Biodiversity Studies of the Hanford Site 2002-2003

Full text

Biodiversity Studies
of the Hanford Site
2002-2003
FINAL REPORT: AUGUST 2003

Biodiversity Studies
of the Hanford Site
Final Report: 2002–2003
Editors
James R. Evans
Marita P. Lih
Peter W. Dunwiddie
Contributors
Florence E. Caplow
Richard Easterly
Peter J. Landholt
Terry T. McIntosh
Jennifer K. Meisel
Robert L. Newell
John J. Nugent
Debra Salstrom
Dennis L. Strenge
Richard S. Zack
Prepared by The Nature Conservancy of Washington
for the U.S Department of Energy and the U.S. Fish
and Wildlife Service, Hanford Reach National
Monument, in partial fulfillment of federal grant
DE-FG-06-02RL14344.
August 29, 2003
Washington Field Office
217 Pine Street, Suite 1100
Seattle, WA 98101

BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
I
Executive Summary
Background
The Hanford Site is recognized as a critical reservoir of biodiversity for the semi-arid interior of the Pacific
Northwest. Less than 40% of the great shrub-steppe ecosystem that once dominated the Columbia Plateau of
Washington, Oregon, and Idaho has escaped development to date, and much of what remains unconverted
exists in a highly degraded condition. The biological importance of the Hanford Site’s relatively undisturbed
shrub-steppe, riverine, and riparian habitats only increases as more and more of the surrounding landscape is
converted to urban or agricultural uses.
A decade ago, the U.S. Department of Energy and The Nature Conservancy of Washington cooperated in
conducting an inventory of the natural biological diversity of the Hanford Site. Between 1994 and 1998,
researchers surveyed the length and breadth of the site, identifying, cataloging, and mapping the plants,
animals, and biological communities of this special landscape. This work culminated with the publication of
the volume Biodiversity Inventory and Analysis of the Hanford Site: Final Report, 1994–1999 (Soll et al.
1999). The inventory documented occurrences of dozens of rare taxa, mapped critical biological resources
such as plant communities, and documented concerns regarding invasive species. Although the study
accomplished much of its mission and provided a great deal of valuable information, some questions
remained unanswered, and new information provided by the report generated many new questions. The
current work is intended to address some of these questions.
The Hanford Site and the Hanford Reach National Monument
The Hanford Site was established in 1943 for the Manhattan Project of the United States Department of
Defense. The 586-square-mile site has been managed by the Department of Energy (DOE) and its
predecessors since that time. In May 2000, 175,000 acres of the Hanford Site surrounding Central Hanford
was designated as the Hanford Reach National Monument by proclamation of President William J. Clinton.
DOE continues to hold title to Monument lands, is the primary manager for some portions of the Monument,
and cooperates with USFWS in comanagement of other Monument Lands. Five management units of the
Hanford Reach National Monument—the Fitzner-Eberhardt Arid Lands Ecology Reserve, the McGee Ranch–
Riverlands Unit, the Saddle Mountain Unit, the Wahluke Unit, and the River Corridor Unit—encircle Central
Hanford, which remains under DOE management.
The Hanford Site lies within the Columbia Basin, the hottest, driest part of Washington state (Franklin and
Dyrness 1973). Annual precipitation varies with elevation, from as little as 16 cm at the lowest elevations (ca.
400 ft./122 m) up to 35 cm along the crest of Rattlesnake Mountain (3500 ft./1067 m). Major soil types
include sandy soils, which are typical of lower elevations, as well as silt loams and stony loams. Upland
vegetation, where undisturbed, is dominated by Wyoming big sagebrush (Artemisia tridentata ssp.
wyomingensis) and associated shrubs, perennial bunchgrasses, and forbs, especially on zonal, silt loam soils.
Plant communities on sandy soils and stony loams may be characterized by bitterbrush (Purshia tridentata)
and desert buckwheat (Eriogonum) species, respectively, along with associated grasses and forbs. Where
disturbed, communities may be converted to annual grasslands dominated by cheatgrass (Bromus tectorum).
Riparian areas are characterized by shrubs such as woods rose (Rosa woodsii), mock orange (Philadelphus
lewisii), and traveler’s joy (Clematis ligusticifolia), by occasional trees such as black cottonwood (Populus
trichocarpa), quaking aspen (P. tremuloides) and willows (Salix spp.), and by moisture-loving graminids and
forbs.

EXECUTIVE SUMMARY
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
II
The Hanford Site and the Hanford Reach National Monument constitute a conservation site of national and
regional importance (Soll et al. 1999). The landscape scale of the shrub-steppe ecosystem, the diversity of
habitats varying with substrate, elevation, and other factors, the relatively undisturbed nature of much of the
site, and the large relatively intact tracts of native shrub-steppe vegetation make the site a unique haven for
native biodiversity of all kinds. Riverine and riparian habitats are equally important. The Monument
encompasses most of the Hanford Reach. The 51-mile Reach is the last free-flowing non-tidal stretch of the
Columbia River in the United States and is home to the last major salmon spawning grounds on the great
river, as well as other aquatic resources.
Areas of Research
VEGETATION OF THE MCGEE RANCH–RIVERLANDS UNIT
The McGee Ranch–Riverlands Unit of the Hanford Reach National Monument occupies approximately 9,100
acres bounded by State Route 24 to the south and east, the Columbia River to the north, and private lands to
the west. The unit is characterized by diverse soils and topography. The vascular plant communities are
diverse as well. Topography, geology, fire history, and land-use history have combined to create a complex
mosaic of vegetation types within the McGee Ranch–Riverlands Unit. This survey delineated 245 polygons of
existing vegetation representing 17 major vegetation types. The greatest diversity in vegetation types occurred
along the crest of Umtanum Ridge and adjacent areas. The gentle slopes down to the Cold Creek Valley south
of Umtanum Ridge, along with the Riverlands area to the north, tended to have relatively more uniform
vegetation, as reflected by the fewer, larger polygons identified there.
The McGee Ranch–Riverlands Unit contains large-scale examples of characteristic native shrub-steppe plant
communities of regional importance. These high-quality plant communities include big sagebrush/needle-
and-thread (Artemisia tridentata/Stipa comata), big sagebrush/bluebunch wheatgrass (Artemisia
tridentata/Pseudoroegneria spicata), stiff sagebrush/Sandberg’s bluegrass (Artemisia rigida/Poa secunda),
big sagebrush-spiny hopsage/Sandberg’s bluegrass (Artemisia tridentata-Grayia spinosa/Poa secunda), and
winterfat/needle-and-thread – Sandberg’s bluegrass (Eurotia lanata/Stipa comata-Poa secunda). These areas
have been proposed for inclusion in Washington state’s Natural Heritage database as Element Occurrences,
representing native landscapes of significant conservation value. The Unit also contains some areas that are
highly degraded, especially where agricultural activities and other developments have taken place in the past.
BIOLOGICAL SOIL CRUSTS OF THE HANFORD REACH NATIONAL MONUMENT
Biological soil crusts are complex groupings of organisms that occupy soil surfaces in many arid and semi-
arid landscapes. The dominant organisms that comprise biological soil crusts are lichens, bryophytes (mostly
mosses as well as a few liverworts), and cyanobacteria. These crusts perform a number of ecologically
important roles that contribute to the production, hydrology, nutrient cycling, and other functions of arid land
ecosystems, and are an important component of the biodiversity of these lands. In general these crusts are
highly sensitive to disturbance. Biological soil crusts of the Hanford Reach National Monument are typically
fragmented and in early to middle successional states resulting from the site’s history of wildfire, domestic
grazing, and anthropogenic activities.
The objectives of this study were to extend the biodiversity inventories of lichens and bryophytes begun
during the 1990s on the Hanford Site and to begin investigations into the community associations these
organisms form with each other and with vascular plant communities. The Hanford Reach National
Monument has a rich diversity of lichens and mosses that are found in shrub steppe plant communities as well
as in a variety of other habitats. Over 120 taxa of lichens and mosses were found within the Monument. The
study found 54 lichen and 24 moss taxa growing as part of the terrestrial soil crust community. Twenty-six
additional lichen taxa and five moss taxa were collected growing on rock outcrops, stones, or talus. Eleven

EXECUTIVE SUMMARY
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
III
lichen taxa are epiphytic on bark of shrubs and trees, and five species of mosses are associated with wetland
habitats.
The study of soil crust communities and their relationships to environmental factors is at a very early stage.
This study tentatively describes three late-successional soil crust communities found on the Monument. The
Trapeliopsis steppica – Bryoerythrophyllum columbianum Community occurs on silt loam soils on the west
side of the Monument; the Syntrichia spp. – Caloplaca tominii Community occurs on sandier soils on the
North Slope; and the Phaeorrhiza sareptana – Lecanora spp. – Encalypta rhaptocarpa Community occurs on
stony loams and lithosolic soils at higher elevations along Rattlesnake Mountain, the Rattlesnake Hills, and
the Saddle Mountains.
We are still only beginning to learn about the extent of the biodiversity of biological soil crusts on the
Hanford Site and to document their role in plant communities and ecosystem processes. Further research in
this area is likely to uncover additional species and to build our understanding of the composition, structure,
and function of biological soil crusts in arid ecosystems. At present, no proven techniques exist for the
restoration of microbiotic crusts at a landscape scale. Therefore, all management activities related to
restoration, invasive species, and fire management, along with general road and facilities maintenance, should
be conducted in such a way as to minimize or eliminate any adverse effect on existing microbiotic crust.
RARE PLANTS
The results of rare plant surveys during the 1990s confirmed the Hanford Site as a critical area for the
conservation of rare shrub-steppe, riparian, and aquatic plant taxa in Washington state. Demographic
information is necessary to interpret population fluctuations and guide management activities in the
conservation of rare species. However, little is known about the reproduction and other life history traits of
Hanford’s important rare plants. The objectives of rare plant studies during the 2002 field season were to
collect and analyze data regarding the status and population dynamics of three of Hanford’s rare plant taxa.
Taxa that were targeted for study included the local endemics Umtanum desert buckwheat (Eriogonum
codium), and White Bluffs bladderpod (Lesquerella tuplashensis), and the more widespread Columbia
yellowcress (Rorippa columbiae). An additional objective was to survey potential habitats for the
reintroduction of northern wormwood (Artemisia campestris ssp. borealis var. wormskioldii) along the
Columbia River.
Since 1997 there has been a precipitous decline in the number of patches and in the number of stems of
Columbia yellowcress on the Hanford Reach. In 2002 less than 200 stems were seen in an area which had
supported at least 36,000 stems in 1992. Little or no sexual reproduction was observed during the last two
monitoring years, 1998 and 2002. The cause of this population decline is not known with certainty but may be
related to changes in river hydrology resulting from upstream flow control. Careful monitoring of this
population over the next three years, along with an analysis of river flow regimes over the period of perceived
decline, is strongly recommended.
Since population monitoring efforts for Umtanum desert buckwheat were initiated in 1997, only a single
seedling has established successfully, while approximately 10% of monitored plants have suffered mortality.
Because of the relatively short time that monitoring has been conducted, it is not clear if these observations
indicate a true decline of the population or a situation of extremely episodic recruitment; however, the
observed trends are cause for concern over this narrow endemic. Continued monitoring and protection of this
sensitive species’ habitat is strongly recommended.
The population size of White Bluffs bladderpod appears to fluctuate widely from year to year. Population size
estimates based on monitoring efforts in 2002 represent the lowest levels since monitoring of this taxon began
in 1997. However, this estimate falls within the possible surveyor error of 1997 estimates. Too little is known
as yet regarding natural population fluctuations of this rare species to support predictions regarding
population trends. A full monitoring once every three to five years is recommended to determine whether
population numbers remain within acceptable limits. No immediate threat to the overall population is
perceived; however, portions of the population are threatened by slumping of their White Bluffs habitat and

EXECUTIVE SUMMARY
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
IV
by invasive species. These issues must be addressed in order to ensure the continuing viability of the sole
population of this Hanford endemic.
No existing populations of northern wormwood were found in surveys along the Hanford Reach. However, a
number of islands in the Reach exhibited habitats that were highly similar to offsite areas this rare taxon
currently occupies. Areas that appeared most suitable were mapped as potential reintroduction sites for
northern wormwood.
AQUATIC MACROINVERTEBRATES
The primary objective of this study was to survey and compile existing records of aquatic macroinvertebrates
of the Hanford Reach, its local tributaries, and spring streams on the Hanford Reach National Monument in
order to document changes to the taxa of aquatic macroinvertebrates in these environments over time.
Additional sampling sought to assess the status of crayfish and western pearl mussels on the Hanford Reach
and to assess the status of aquatic macroinvertebrate diversity in spring streams of the Arid Lands Ecology
(ALE) Reserve in the aftermath of a landscape-scale wildfire in summer 2000.
Macroinvertebrate taxa new to the Hanford Site continue to be collected in the Hanford Reach and in the
spring streams of the ALE Reserve. The macroinvertebrate fauna of the Hanford Reach has changed over the
last 50 years, with certain taxa and taxonomic groups increasing while others decrease. Ephemeroptera
(mayfly) diversity has increased; Plecoptera (stoneflies) have disappeared; Trichoptera (caddisfly) diversity
and abundance remain high; Odonata (dragonflies and damselflies), Hemiptera (true bugs), Lepidoptera
(butterflies and moths) and Coleoptera (beetles) are rare; and Diptera (fly) diversity remains relatively
constant. More intensive sampling of the Hanford Reach and its shoreline is recommended to create a
comprehensive inventory of macroinvertebrates for the Reach. Long-term, seasonal studies are needed to
develop baseline data that can be used to monitor the effects of both natural and anthropogenic disturbances,
such as unstable hydrological regimes, on benthic fauna over time.
Aquatic invertebrate diversity has changed over time in the spring streams of the ALE Reserve as well. Some
historically collected taxa have not been collected in over a decade; however, previously uncollected taxa
have been recorded as recently as 2000. Rattlesnake Spring was affected by the 2000 wildfire, with
invertebrate diversity declining as a result of the deposit of large amounts of sediment and plant debris in the
aftermath of the fire. Sampling in Benson, Snively, and Rattlesnake springs should occur periodically to
document the status of invertebrate populations and to monitor recovery from the 2000 wildfire. Monitoring
of stream morphology and chemistry can provide valuable baseline information to help assess the impacts of
erosion and sedimentation and to interpret changes in invertebrate diversity and abundance in these spring
channel ecosystems.The Pacific crayfish (Pacifasticus leniusculus) population on the Hanford Reach appears
to be robust. However, the western pearl mussel (Margaritinopsis falcata) seems to have nearly disappeared
from the Reach, where it was once abundant. An intensive survey for possible remnants of this once-large
population is recommended. One introduced mollusk, the Asiatic clam (Corbicula fluminea) appears to be
extremely abundant in the Hanford Reach. Impacts of the huge population of this mollusk on other benthic
fauna are unknown.
TERRESTRIAL INVERTEBRATES
The primary objective of this study was to extend the entomological inventories of the 1990s regarding
selected taxonomic groups, to extend the inventory to groups not previously examined, and to examine
habitats on the Wahluke and Saddle Mountain Units that had not been sampled during previous studies.
The Hanford Site represents the closest approximation to a pre-European colonization insect fauna that can be
found in Eastern Washington. Patterns of entomological diversity suggest a strong connection between the
expanses of native vegetation and other natural habitat features on the Hanford Site and the predominantly

EXECUTIVE SUMMARY
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
V
native invertebrate fauna, compared to the introduced invertebrate fauna of the surrounding urban and
agricultural landscape.
The 2002–2003 study collected and processed approximately 12,000 specimens of terrestrial invertebrates. To
date, 376 species, representing approximately 50–60% of the insects collected, have been identified thus far,
with the majority of identifications coming from the Lepidoptera (moths) and Coleoptera (beetles). Numerous
species not previously collected at Hanford, especially in the orders Trichoptera (caddisflies) and Lepidoptera,
have been added to the invertebrate fauna of the Hanford Site. Approximately 200–300 species are still
awaiting identification. It is likely that it is from these specimens that the most significant finds will be made.
Most of these specimens are in the hands of taxonomic experts. Groups with the highest percentages of
unidentified specimens include Lepidoptera and Coleoptera while identifications for groups such as
Siphonaptera (fleas) and Dermaptera (earwigs) are complete.
Several groups of insects appear to be associated with areas of extensive microbiotic soil crusts. The
Hydracarina (mite) and Collembola (springtail) fauna represented significant portions of pit fall samples
where the crust was intact and were virtually nonexistent in samples where the crust had been destroyed. The
distribution of snow scorpionflies (Boreus: Mecoptera: Boreidae) exhibits the same contrast: The larvae of
these small insects feed on mosses within the soil crust and are not found in areas where the crust has been
degraded or destroyed. Intact shrub-steppe areas of the Hanford Site appear to be especially rich in this genus.
During the 1990s four species of Boreus were collected on the ALE Reserve, making Hanford the only site
known to the world authority on this taxonomic group from which four species have been recorded.
The sand dune habitats of Central Hanford and the Wahluke Slope exhibit an invertebrate fauna distinct from
other areas of the site. Based on collections from dune habitats around the state, it appears that a number of
these dune taxa are also limited outside the Hanford Site due to isolation of habitats and, perhaps, habitat
degradation and conversion.
At the time of the publication of Soll et al. (1999), 1,536 species of terrestrial arthropods had been identified.
Since that time another 143 species have been positively identified, making a total of 1,679 species. These
additions include species identified after 1999 and those thus far identified from the 2002–2003 study.
Although no species new to science have been added from the 2002–2003 study as yet, three new species
have been identified from previous collections since Soll et al. (1999) for a total of 46 from Hanford studies
over the last decade. The three new species include a scarab beetle (Aphodius sp.), a snow scorpionfly
(Boreus sp.) and a parasitic wasp (Macrocentrus shawi Ahlstrom). The number of species new to Washington
state, difficult to ascertain precisely because of the lack of catalogs and checklists, is estimated at 150–200
species.
Insects not only are important as organisms of biological study, but they also have economic importance as
pests and beneficials. Entomological studies of the site continue to indicate that Hanford is unusual in its lack
of pest species and in its abundance of native taxa. The native arthropod fauna of the Hanford Site provides
one of the few remaining areas where potentially beneficial native insects may be sought and, perhaps, found.
Insect diversity may also serve as an indicator of habitat condition, and Hanford can provide an excellent
laboratory for studies of this nature. Areas of the Hanford Reach National Monument and Central Hanford
should be considered for long-term entomological diversity studies.
INVASIVE PLANT SPECIES INVENTORY AND MANAGEMENT
Invasive plant species represent one of the most serious threats to the native biodiversity of the Hanford Site.
Invasive plant species compete against and reduce habitat available for native plant species, alter ecosystem
structure and function, disrupt food chains and other ecosystem characteristics vital to wildlife, and can
dramatically alter key ecosystem processes such as hydrology, productivity, nutrient cycling, and fire regime.
Noxious weed surveys in 2002 and 2003 confirmed the presence of 23 invasive plant species on the Hanford
Reach National Monument, including three species that had not previously been documented on Monument
lands. Overall, the inventory recorded more than 400 occurrences of invasive species, infesting more than
9000 acres (> 3600 ha) over all management units of the Monument. Diffuse knapweed (Centaurea diffusa)
was the most widespread and abundant invasive plant species surveyed, infesting more than 3600

EXECUTIVE SUMMARY
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
VI
acres (> 1480 ha), just over 40% of the land area occupied by all invasive species. A number of other species
of concern, such as Yellow starthistle (Centaurea solstitialis), rush skeletonweed (Chondrilla juncea),
saltcedar (Tamarix spp.), Russian knapweed (Acroptilon repens), whitetop (Cardaria draba), and other species
are widespread on the Monument. Several invasive species, such as dalmatian toadflax (Linaria dalmatica)
and Scotch thistle (Onopordum acanthium), are presently known from only one or a few small colonies on the
Monument. Several invasive species that have not yet been recorded on the Monument are present nearby on
Central Hanford or elsewhere in the Columbia Basin. Invasive species that are already nearly ubiquitous, such
as cheatgrass (Bromus tectorum), were not included in the inventory. The number of invasive species of
concern, along with the size and complexity of the Monument landscape, present extreme challenges to
managers of the Hanford Reach National Monument. To assist in maximizing the effectiveness of limited
resources for invasive species management, a weed management plan for the Monument has been developed.
The plan includes protocols prioritizing invasive plant species and infestated sites for treatment based on
characteristics of the invasive species, the size of the infestation, and the proximity of the infestation to key
conservation targets. A listing of highest priority treatment sites is included, along with a discussion of
treatment options for each species based on weed management literature and the experience of local
professionals . An integrated approach is recommended, utilizing manual, mechanical, and chemical means of
control individually or in combination as appropriate depending on characteristics of the invasive species to
be treated, the size of the infestation, and other factors. Ongoing, thorough monitoring is a critical element of
the plan. An aggressive, coordinated weed management program will be necessary to adequately conserve the
natural features that the Hanford Reach National Monument was designated to protect.
Conclusions
Biological studies continue to confirm Hanford’s national and regional importance as a refuge for both rare
and common species and communities that were once far more widespread in the inland Northwest.
Biodiversity studies over the last decade have allowed us to learn much about the natural systems of the
Hanford Site, and of the diverse array of native organisms that populate these systems and contibute to their
natural processes. However, in many ways, our investigations have just begun to scratch the surface of the
complex biology of this arid land. Studies of aquatic and terrestrial invertebrates and of biological soil crusts
continue to uncover new species; our understanding of the function of these organisms in ecosystems is in its
infancy. Our knowledge of rare plant population trends is severely limited by the short time period during
which we have been able to study them; a much more long-term perspective is required to provide the
information necessary to adequately manage these limited resources. Plant communities may change
gradually in response to long-term fluctuations in climate and rapidly in response to episodic events such as
wildfires and other disturbances. Invasive species populations are dynamic and will continue to pose a
challenge for natural resource managers into the forseeable future, a challenge that will only increase with the
increasing globalization of commerce. A strong commitment to ongoing monitoring programs to maintain up-
to-date capabilities for assessment of the status of biological resources and the threats to those resources
throughout the Hanford Site is highly recommended.
The biological inventories and associated studies conducted over the past decade have shown that every
management unit of what is now the Hanford Reach National Monument, as well as Central Hanford,
possesses important resources that contribute to the biodiversity of the site and the region. It is important that
these biological values be given strong consideration by the U.S. Fish and Wildlife Service, the U.S.
Department of Energy, and the engaged public in planning for the use and development of the Hanford Reach
National Monument and the other lands of the Hanford Site.

BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
VII
Contents
Introduction ......................................................................................................................................................1
1. Introduction............................................................................................................................................... 3
Current Management Units of the Hanford Site and the Hanford Reach National Monument ..............4
Current Scope of Work ...........................................................................................................................7
Plant Communities .........................................................................................................................................9
2. Vegetation of the McGee Ranch–Riverlands Unit. Richard Easterly and Debra Salstrom ............... 11
Introduction...........................................................................................................................................11
Site Description and Geology .....................................................................................................11
Land Use History ........................................................................................................................12
Methods ................................................................................................................................................12
Taxonomic Nomenclature...........................................................................................................13
Results and Discussion .........................................................................................................................14
General Vegetation Description..................................................................................................17
Vegetation Condition ..................................................................................................................18
Natural Heritage Element Occurrences.......................................................................................18
Management Recommendations...........................................................................................................21
3. Biological Soil Crusts of the Hanford Reach National Monument. Terry T. McIntosh .................... 23
Introduction...........................................................................................................................................23
Biological Soil Crusts: Composition and Function.....................................................................23
Previous Soil Crust Research in the Hanford Area.....................................................................24
Constraints on the Identification of Lichens and Bryophytes.....................................................24
Methods ................................................................................................................................................25
Taxonomy and Nomenclature.....................................................................................................29
Results...................................................................................................................................................29
Lichens........................................................................................................................................29
Bryophytes ..................................................................................................................................33
Community Analyses..................................................................................................................34
Discussion.............................................................................................................................................38
Lichens........................................................................................................................................38
Bryophytes ..................................................................................................................................39
Community Analyses..................................................................................................................39
Environmental Factors ................................................................................................................41
Recommendations.................................................................................................................................42
Biodiversity Studies ....................................................................................................................42
Research and Monitoring ............................................................................................................42

CONTENTS
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
VIII
Rare Plants ..................................................................................................................................................... 43
Overview....................................................................................................................................................... 45
Purpose and Scope................................................................................................................................45
4. Current Status of Columbia Yellowcress (Rorippa columbiae) on the Hanford Reach.
Florence E. Caplow ......................................................................................................................................47
Introduction .......................................................................................................................................... 47
Methods................................................................................................................................................ 47
BLM Monitoring Transects........................................................................................................ 47
Visual Surveys............................................................................................................................ 48
Results .................................................................................................................................................. 53
Discussion ............................................................................................................................................ 54
Recommendations ................................................................................................................................56
5. Current Status of Umtanum Desert Buckwheat (Eriogonum codium) on the Hanford Site.
Florence E. Caplow ......................................................................................................................................57
Introduction .......................................................................................................................................... 57
Methods................................................................................................................................................ 57
Results .................................................................................................................................................. 57
Annual Mortality and Recruitment............................................................................................. 57
Inflorescence Production ............................................................................................................ 58
Seedling Production.................................................................................................................... 58
Discussion ............................................................................................................................................ 60
Recommendations ................................................................................................................................60
6. Current Status of White Bluffs Bladderpod (Lesquerella tuplashensis) on the Hanford Site.
Florence E. Caplow ......................................................................................................................................63
Introduction .......................................................................................................................................... 63
Methods................................................................................................................................................ 63
Results .................................................................................................................................................. 63
Discussion ............................................................................................................................................ 65
Recommendations ................................................................................................................................65
Sampling Protocols..................................................................................................................... 65
Invasive Species ......................................................................................................................... 67
7. Survey for Northern Wormwood (Artemisia campestris subsp. borealis var. wormskioldii) and
Potential Habitat on the Islands of the Hanford Reach. Florence E. Caplow ........................................69
Invertebrates.................................................................................................................................................. 71
8. Aquatic Macroinvertebrates. Robert L. Newell..................................................................................... 73
Introduction .......................................................................................................................................... 73
Purpose and Scope................................................................................................................................73
Methods................................................................................................................................................ 73
The Hanford Reach of the Columbia River................................................................................ 73
Spring Streams of the Arid Lands Ecology Reserve .................................................................. 74
Results and Discussion......................................................................................................................... 75
Literature Review ....................................................................................................................... 75
Comparisons of Invertebrate Communities Over Time.............................................................. 76
Overview of Selected Aquatic Insect Orders.............................................................................. 88
Origin of Adult Trichoptera (Caddisflies) .................................................................................. 91
Wildfire Effects on Spring-Stream Invertebrates ....................................................................... 93
Status of the Pacific Crayfish, Pacifasticus leniusculus, in the Hanford Reach......................... 93
Status of the Western Pearl Mussel, Margaritinopsis falcata, in the Hanford Reach................ 93

CONTENTS
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
IX
Summary and Conclusions ...................................................................................................................95
Recommendations.................................................................................................................................96
9. Terrestrial Invertebrates. Richard S. Zack, Dennis L. Strenge, and Peter J. Landolt........................ 97
Introduction...........................................................................................................................................97
Purpose and Scope ................................................................................................................................97
Methods ................................................................................................................................................97
Results and Discussion .........................................................................................................................98
Treatments of Individual Orders .................................................................................................99
Conclusions.........................................................................................................................................103
Recommendations...............................................................................................................................104
Invasive Plant Species...............................................................................................................................105
10. Invasive Plant Species Inventory of the Hanford Reach National Monument: 2002–2003.
James R. Evans, John J. Nugent, and Jennifer K. Meisel ....................................................................... 107
Introduction.........................................................................................................................................107
Methods ..............................................................................................................................................107
Inventory Search Strategies ......................................................................................................110
Results and Discussion .......................................................................................................................110
Characterization of Infestations of Target Species by Management Area................................116
Conclusions.........................................................................................................................................117
Recommendations...............................................................................................................................117
11. Invasive Plant Species Management Plan for the Hanford Reach National Monument.
James R. Evans, John J. Nugent, and Jennifer K. Meisel ....................................................................... 119
Introduction.........................................................................................................................................119
Impacts of Invasive Plant Species.............................................................................................119
Management Setting .................................................................................................................119
Management Program Overview ........................................................................................................120
Resource-Based Management...................................................................................................120
Prevention .................................................................................................................................120
Early Detection and Sustained Monitoring...............................................................................121
Prioritization of Species and Sites ............................................................................................121
Integrated Treatment Program for Priority Species and Sites...................................................123
Adaptive Management ..............................................................................................................124
Building Partnerships................................................................................................................124
Education and Outreach............................................................................................................124
Fire Management ......................................................................................................................124
Conclusions.........................................................................................................................................125
Conclusions..................................................................................................................................................127
References....................................................................................................................................................131
Appendices...................................................................................................................................................150
Appendix A – Biodiversity Studies Contributors and Personnel ......................................................... 152
Appendix B – Acknowledgements ........................................................................................................... 154

CONTENTS
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
X
List of Tables
Table 1.1. Research conducted in this study, including management units where work was performed,
and time frames. ................................................................................................................................8
Table 2.1. Partial list of priority species used to define polygon boundaries and generate
mapping-unit names. ....................................................................................................................... 13
Table 2.2. Coverage of existing plant community types on the McGee Ranch–Riverlands Unit, Hanford
Reach National Monument.............................................................................................................. 14
Table 2.3. Ecosystem Element Occurrences on the McGee Ranch–Riverlands Unit, Hanford Reach
National Monument, with tentatively assigned ranks...................................................................... 21
Table 3.1. Biological soil crust community sampling sites, 2002–2003........................................................... 25
Table 3.2. Terrestrial Lichens on the Hanford Reach National Monument, 2002–2003. ................................. 30
Table 3.3. Saxicolous lichens on the Hanford Reach National Monument, 2002–2003................................... 32
Table 3.4. Epiphytic lichens on the Hanford Reach National Monument, 2002–2003..................................... 32
Table 3.5. Bryophytes on the Hanford Reach National Monument, 2002–2003. ............................................. 33
Table 3.6. Proportion of species variance explained. Non-metric multidimensional scaling (NMS)
of biological soil crust communities of the Hanford Reach National Monument, 2002–2003. ...... 34
Table 3.7. Stress in relation to dimensionality (number of axes). Non-metric multidimensional
scaling (NMS) ordination, biological soil crust communities of the Hanford Reach National
Monument, 2002–2003.................................................................................................................... 34
Table 3.8. Species codes for lichen and bryophyte taxa used in non-metric multidimensional
scaling (NMS) analysis (Fig. 3.2).................................................................................................... 36
Table 3.9. Correlations of community and environmental variables with ordination axes. Non-metric
multidimensional scaling (NMS) of biological soil crust communities of the Hanford Reach
National Monument, 2002–2003..................................................................................................... 38
Table 4.1. Number of stems observed per transect, Hanford Reach population of Columbia
yellowcress (Rorippa columbiae), 1994–2002................................................................................ 54
Table 4.2. Average numbers of flowers and fruit per plant, Hanford Reach population of Columbia
yellowcress (Rorippa columbiae), 1994–2002................................................................................ 54
Table 4.3. General trends in Columbia yellowcress (Rorippa columbiae) population on the Hanford
Reach, 1982–2002. .......................................................................................................................... 55
Table 5.1. Annual mortality and recruitment of Umtanum desert buckwheat (Eriogonum codium) on
the Hanford Site............................................................................................................................... 58
Table 5.2. Total seedling production of Umtanum desert buckwheat (Eriogonum codium) on the
Hanford Site, 1997–2002................................................................................................................. 61
Table 6.1. Comparison of confidence intervals for White Bluffs bladderpod (Lesquerella tuplashensis)
sampling 10 or 20 transects. ............................................................................................................ 67
Table 7.1. Potential habitat for northern wormwood (Artemisia campestris subsp. borealis var.
wormskioldii) on islands in the Hanford Reach............................................................................... 70
Table 8.1. Summary of all benthic invertebrate taxa reported by the major benthic studies on the
Hanford Reach, 1948–1998, including all organisms, immatures and adults. ................................ 77
Table 8.2. Aquatic benthic invertebrate taxa collected from tributaries to the Hanford Reach of
the Columbia River, February 1998 (Newell 1998). ....................................................................... 82
Table 8.3. Aquatic invertebrate taxa collected from Rattlesnake Spring. ......................................................... 83
Table 8.4. Aquatic invertebrate taxa collected from Snively Spring................................................................. 85
Table 8.5. Aquatic Macroinvertebrates from Benson, Snively, and Rattlesnake Springs collected and
identified by Pickel (2000). ............................................................................................................. 86
Table 8.6. Taxa of adult Ephemeroptera (mayflies) captured by Newell in 1998 in the vicinity of the
Columbia River, Richland, WA. ..................................................................................................... 88

CONTENTS
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
XI
Table 8.7. Hemiptera collected on or near the Hanford Site..............................................................................89
Table 8.8. Odonata (adults and nymphs) captured in or near the following locations on the Hanford
Site by Newell (1998) and Zack (1998, pers. comm.). ....................................................................90
Table 8.9. Caddisfly adults collected using ultraviolet and mercury vapor light trapping and
Lepidoptera pheromone traps...........................................................................................................91
Table 9.1. Number of species level identifications of terrestrial invertebrates, 2002–2003 study. ...................99
Table 9.2. Arthropod taxa new to science collected at Hanford, 1994–2003. .................................................100
Table 10.1. Target list of invasive plant species for the Hanford Reach National Monument. .......................108
Table 10.2. Occurrences and areas infested by target invasive plant species, Hanford Reach National
Monument 2002–2003. ..................................................................................................................115
Table 11.1. Invasive plant species treatment priorities, Hanford Reach National Monument, 2002–2003.....120
List of Figures
Fig. 1.1. The Hanford Site, including Central Hanford and the Hanford Reach National Monument................5
Fig. 2.1. Existing vegetation of the McGee Ranch–Riverlands Unit, Hanford Reach National
Monument, 2002.................................................................................................................................15
Fig. 2.2. Proposed Natural Heritage Element Occurrences on the McGee Ranch–Riverlands Unit,
Hanford Reach National Monument...................................................................................................19
Fig. 3.1. Locations of microbiotic crust community sampling sites, Hanford Reach National
Monument, 2002–2003.......................................................................................................................27
Fig. 3.2. Non-metric multidimensional scaling (NMS) ordination of biological soil crust communities:
triplot of sites, lichen and bryophyte taxa, and environmental vectors...............................................35
Fig. 4.1. Range of Columbia yellowcress (Rorippa columbiae) on the Hanford Reach....................................49
Fig. 4.2. Location of BLM monitoring transects established in 1991 for Columbia yellowcress
(Rorippa columbiae)...........................................................................................................................51
Fig. 4.3. Stem counts of Columbia yellowcress (Rorippa columbiae) in study plots on the Hanford
Reach, 1994–2002...............................................................................................................................53
Fig. 5.1. Average number of infloresences of Umtanum desert buckwheat (Eriogonum codium) per
plant, 1997–2002.................................................................................................................................59
Fig. 5.2 Annual seedling production of Umtanum desert buckwheat (Eriogonum codium), 1997–2002.
Results are from July surveys..............................................................................................................59
Fig. 5.3. Proportion of total seedlings of Umtanum desert buckwheat (Eriogonum codium) produced
by the three most productive quadrats, 1997–2002.............................................................................59
Fig. 6.1. Total number of flowering plants of White Bluffs bladderpod (Lesquerella tuplashensis;
10 transects), 1997–2002.....................................................................................................................64
Fig. 6.2. Estimated number of flowering plants of White Bluffs bladderpod (Lesquerella tuplashensis)
in the sample area................................................................................................................................64
Fig. 6.3 Total number of flowering plants of White Bluffs bladderpod (Lesquerella tuplashensis) per
transect (10 transects), 1997–2002......................................................................................................66
Fig. 6.4 Relative spatial distribution of flowering plants of White Bluffs bladderpod (Lesquerella
tuplashensis; 10 transects), 1997–2002...............................................................................................66
Fig. 10.1. Search areas for invasive plant species, Hanford Reach National Monument, 2002–2003............111
Fig. 10.2. Areas infested by invasive plant species, Hanford Reach National Monument, 2002–2003..........113

CONTENTS
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
XII

Introduction

BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
3
1. Introduction
The Hanford Site was established in 1943 for the Manhattan Project of the United States Department of
Defense. Decades of restricted development and limited public use over most of the site have resulted in the
site’s recognition as a critical reservoir of biodiversity for the semi-arid interior of the Pacific Northwest (Soll
et al. 1999, Clinton 2000, Rickard et al. 1988). Less than 40% of the great shrub-steppe ecosystem that once
dominated the Columbia Plateau of Washington, Oregon, and Idaho has escaped development to date, and
much of what remains unconverted exists in a highly degraded condition (DOE-RL 2001). The biological
importance of the Hanford Site’s relatively undisturbed shrub-steppe habitats only increases as more and
more of the surrounding landscape is converted to other uses.
The aquatic and riverine habitats of the Hanford Site also represent areas of highly significant conservation
value for the interior Northwest. The 51-mile extent of the Hanford Reach represents the last free-flowing,
non-tidal stretch of the Columbia River within the United States, critical habitat for the rivers last great runs
of anadramous fish, and important stopover and nesting sites for migratory birds. Freshwater springs are all
the more valuable for their scarcity, standing out like green jewels in the surrounding semi-arid landscape,
providing habitats for specialized plant and insect life, offering nest sites for migratory songbirds, and
focusing the activities of upland wildlife.
The Hanford Site lies within the Columbia Basin, the hottest, driest part of Washington state (Franklin and
Dyrness 1973). Environmental characteristics are summarized in Soll et al. (1999), in Rickard et al. (1988),
and elsewhere. Elevations range from below 400 ft. (122 m) a.s.l. along the Columbia River to more than
3500 ft. (1067 m) at the summit of Rattlesnake Mountain near the western boundary of the site. Annual
precipitation varies with elevation, ranging from as little as 16 cm at the lowest elevations up to 35 cm along
the crest of Rattlesnake Mountain.
Background: The Biodiversity Inventory and Analysis of the Hanford Site, 1992–1999. In 1992 the U.S.
Department of Energy and The Nature Conservancy of Washington entered into a Memorandum of
Understanding, which laid the groundwork for cooperation between the two entities in conducting an
inventory of the natural biological diversity of the Hanford Site. Over four field seasons between 1994 and
1998, researchers surveyed the length and breadth of the site, identifying, cataloging, and mapping the plants,
animals, and biological communities of this special landscape. This important phase of work culminated in
1999 with the publication of the volume Biodiversity Inventory and Analysis of the Hanford Site: Final
Report, 1994–1999 (Soll et al. 1999). The inventory documented occurrences of dozens of rare taxa, mapped
critical biological resources such as plant communities, and documented concerns regarding invasive plant
species. Although the study accomplished much of its mission and provided a great deal of valuable
information, some questions remained unanswered. Moreover, new information provided by the report
generated many additional questions.
Since the publication of Soll et al. (1999) the Hanford Site has experienced significant changes, both on the
landscape as well as in the management arena:
• In June 2000, approximately 195,000 acres of the Hanford Site surrounding Central Hanford was
designated as the Hanford Reach National Monument by proclamation of President William J.
Clinton (Presidential Proclamation 7319). The proclamation calls for the protection of the
Monument’s riparian, aquatic, and upland shrub-steppe habitats, including rare vascular plants,
microbiotic soil crusts, shrub-steppe-dependent wildlife, insects, migratory birds, and fisheries
resources, as well as cultural and geological features.

1. INTRODUCTION
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
4
• In late June 2000, a wildfire burned more than 160,000 acres of the Hanford Site, including nearly all
of the 77,000-acre Fitzner-Eberhardt Arid Lands Ecology Reserve Unit of the newly proclaimed
national monument, along with significant portions of Central Hanford. Wildfires burned smaller
acreages in the Vernita Flats area of the Saddle Mountain Unit, north of the Columbia River, in 2000,
and near the White Bluffs of the Wahluke Unit during July 2002.
• In fall 2003, construction of a large high-voltage powerline is scheduled to traverse Umtanum Ridge
and other portions of the McGee Ranch–Riverlands Unit of the Monument.
Current Management Units of the Hanford Site and the Hanford Reach
National Monument
The Hanford Site consists of Central Hanford and the Hanford Reach National Monument (Fig. 1.1). The
Monument itself is divided into six administrative units. Land ownership for the entire site resides with the
U.S. Department of Energy (DOE). However, the U.S. Fish and Wildlife Service (USFWS) exercises direct
management over 165,000 acres of Monument lands, while the Washington Department of Fish and Wildlife
(WDFW) manages a small recreational access area. The administrative management units of the Hanford Site
are as follows:
• Central Hanford. Central Hanford is a wide expanse of the Columbia River Plain in the center of the
Pasco Basin. Managed by DOE, Central Hanford contains portions of the Hanford Reach National
Monument, most notably the Hanford Dunes and a one-quarter-mile strip along the Columbia River
shoreline (see River Corridor Unit). Other significant natural features of Central Hanford include
Gable Mountain and Gable Butte. Portions of the site have been subjected to considerable human
impacts, from old agricultural sites and townsites to construction camps, reactor sites, and processing
areas associated with the nuclear weapons program of the mid- to late-twentieth century.
• The Fitzner-Eberhardt Arid Lands Ecology (ALE) Reserve. The 77,000-acre ALE Reserve lies
along the southwest boundary of the Hanford Site, in Benton County. The Reserve was officially
recognized as a valuable site for scientific study in 1967 due to the rich and relatively undisturbed
character of its native shrub-steppe ecosystem. The Reserve was subsequently designated a federal
Research Natural Area in 1971. The area, managed by USFWS since 1999, is closed to public uses
and is maintained for scientific and educational purposes.
• The McGee Ranch–Riverlands Unit. This 9100-acre unit of the Monument lies north of ALE and is
managed directly by DOE. The unit lies entirely within Benton County and contains the biologically
diverse Umtanum Ridge area and some intact shrublands as well as powerline corridors and former
agricultural lands, homesteads, and townsites. Public access is limited to the Riverlands area north of
the Midway Substation Road.
• The Vernita Bridge Recreation Area. This small (approximately 800 acres) area on the Columbia
River just north of the Vernita Bridge has been managed by WDFW since 1971, primarily to provide
river access for fishing and boating.
• River Corridor Unit. This 25,000-acre unit of the Monument includes the Hanford Reach of the
Columbia River along with the Columbia River islands and a one-quarter-mile corridor along the
south and west shore of the river. The unit also contains the Hanford Dunes, reportedly the only
active dunefield within Washington state. Management of this unit is multijurisdictional, involving
DOE, USFWS, the U.S. Bureau of Land Management, and state and county agencies. In general, the
south and west shores of the Columbia, its islands, and the Hanford Dunes are managed by DOE,
while the north and east shores of the Columbia are managed by USFWS.

1. INTRODUCTION
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
5
Fig. 1.1. The Hanford Site, including Central Hanford and the Hanford Reach National Monument.

1. INTRODUCTION
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
6

1. INTRODUCTION
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
7
• Saddle Mountain Unit/Saddle Mountain National Wildlife Refuge. This 32,000-acre unit borders
the north shore of the Columbia River and is located entirely within Grant County. This unit of the
Monument, managed by USFWS since 1971, contains sagebrush stands and important rare plant
habitats, along with heavily disturbed former agricultural lands and the Saddle Mountain Lakes, a
large area of irrigation wasteway impoundments. The unit is bisected by State Route 24 but is
otherwise closed to public access.
• Wahluke Unit. The 57,000-acre Wahluke Unit, located primarily in Grant and Franklin counties
(with a small portion in Adams County), is open to the public. This unit, managed by USFWS since
1999, includes most of the Monument’s signature geologic feature, the White Bluffs, as well as
significant shrub-steppe habitats and irrigation district wasteway impoundments.
Current Scope of Work
The Biodiversity Inventory and Analysis of the Hanford Site (Soll et al. 1999) identified a number of areas
where planned inventories could not be completed, or where the findings of preliminary inventories indicated
that additional work was needed. The studies summarized within this current volume were designed to
address some of these gaps in current knowledge of the site’s organisms and understanding of the
relationships between organisms. Field work was begun in 2002, with some field investigations continuing
into 2003 (Table 1.1) Specific objectives of these studies included the following:
• Vegetation mapping. The Biodiversity Inventory and Analysis of the Hanford Site mapped
vegetation over most of the Hanford Site. One remaining major unit, the McGee Ranch–Riverlands
Unit, has now been mapped as a part of these studies (Easterly and Salstrom 2003).
• Microbiotic crusts. Studies of microbiotic crusts accomplished through the Biodiversity Inventory
and Analysis of the Hanford Site were the first attempts to systematically collect and identify soil
mosses and lichens at Hanford. Work during 2002–2003 involved more extensive surveys for these
organisms around the site, surveyed previously unsurveyed habitats such as talus, rock outcrops, and
other habitats, and examined community relationships among soil crust organisms, environmental
variables, and vascular plant communities (McIntosh 2003).
• Rare plant studies. The Biodiversity Inventory and Analysis of the Hanford Site identified numerous
populations of rare vascular plant taxa, including several taxa new to science. Little is known about
the reproduction and other life history traits of many of Hanford’s rarest plants. The recent round of
studies assessed the population status and viability of the Hanford endemics Umtanum desert
buckwheat (Eriogonum codium) and White Bluffs bladderpod (Lesquerella tuplashensis), along with
Columbia yellowcress (Rorippa columbiae), and surveyed for occurrences and potential habitat for
northern wormwood (Artemisia campestris ssp. borealis var. wormskioldii; Caplow 2003).
• Aquatic invertebrates. This portion of the current studies focused on a synthesis of existing
literature on Hanford’s aquatic invertebrates, while conducting new surveys for selected aquatic
invertebrate taxa on the Hanford Reach, and made comparisons of historical collections from spring
stream habitats on the Fitzner-Eberhardt Arid Lands Ecology Reserve with new collections following
a landscape-scale wildfire (Newell 2003).
• Terrestrial invertebrates. Collections of terrestrial invertebrates on the Hanford Site during the
1990s contributed large numbers of taxa new to science and indicated that this area of study would
likely yield many additional contributions to local, regional, and worldwide biodiversity. Ongoing
work at Hanford continues to add to the entomological record of the site (Zack et al. 2003).

1. INTRODUCTION
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
8
• Invasive plant species. Invasive plant species have been identified as one of the greatest threats to
biodiversity on the Hanford Site. This scope of work included two elements to assist site managers in
addressing this issue: 1) an inventory of noxious weeds on the Hanford Reach National Monument,
and 2) development of a noxious weed management plan for the Monument (Evans et al. 2003).
The results of these studies have been provided to the U.S. Department of Energy and to the U.S. Fish and
Wildlife Service, co-managers of the Hanford Reach National Monument, to inform ongoing resource
management and land use decisions.
Table 1.1. Research conducted in this study, including management units where work was performed, and
time frames. Management Units are abbreviated as follows: ALE (Arid Lands Ecology Reserve); HR
(Hanford Reach, River Corridor Unit); HRNM (Hanford Reach National Monument—entire monument); MR
(McGee Ranch–Riverlands Unit); W (Wahluke Unit).
Year
Subject Area 2002 2003
Plant Community Mapping MR
Microbiotic Crusts HRNM HRNM
Rare Plants W, MR, HR
Aquatic Invertebrates HR, ALE
Terrestrial Invertebrates W W
Weed Inventory and Management HRNM HRNM

Plant Communities

BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
11
2. Vegetation of the McGee Ranch–Riverlands Unit
Richard Easterly and Debra Salstrom
Introduction
Between 1994 and 1998, vascular plant communities were inventoried and mapped over most of the Hanford
Site (Soll et al. 1999). These mapping studies, characterized by intensive walking surveys and field checking,
were conducted on the Fitzner-Eberhardt Arid Lands Ecology Reserve and the North Slope (Wilderman
1994), Central Hanford (Easterly and Salstrom 1997), and the south shorelines and islands of the Columbia
River (Salstrom and Easterly 1995). Mapping of the McGee Ranch–Riverlands Unit completes the detailed
vegetation mapping of the Hanford Site. Complete details of this study are reported in Easterly and Salstrom
(2003).
SITE DESCRIPTION AND GEOLOGY
The McGee Ranch–Riverlands Unit of the Hanford Reach National Monument occupies approximately 9,100
acres and is bounded by State Route 24 to the south and east, the Columbia River to the north, and privately-
owned lands to the west. The unit is characterized by diverse soils and topography and by a varied land use
history. The McGee Ranch–Riverlands Unit is under the direct management of the U. S. Department of
Energy.
The study area is located on and adjacent to eastern Umtanum Ridge, which is composed of numerous basalt
flows of the Columbia River Basalt Group. Umtanum Ridge is one of a series of east-west trending anticlines
that comprise the Yakima Fold Belt. It is asymmetrical, with a relatively gentle south slope and a steep,
intensely folded and faulted north slope.
Between some of the upper basalt flows are sedimentary interbeds. The largest of these, the Vantage Interbed,
is the major water-bearing stratum in the area, and the source of numerous cold springs along the north flank
of Umtanum Ridge (Goff 1981). Water in this buried interbed is also likely the source of several artesian
wells on the south flank of the ridge (Goff 1981), such as at the McGee Well.
Eastern Umtanum Ridge is located along the route of catastrophic floods that occurred during the 1.5-2.5
million years of the Pleistocene Epoch (Bjornstad et al. 2001). Umtanum Ridge deflected a major trajectory of
these floodwaters to the east, scouring the north slope of the ridge. The surging and temporarily ponded water
deposited large quantities of fine-textured materials on the south slope of Umtanum Ridge (Lindberg 1994).
On the south side of the ridge, some road cuts expose a carbonate horizon that has developed in the wind- and
water-borne sediments. This carbonate-cemented sandy-silt occurs throughout the fine deposits at a depth of
30-60 cm (Lindberg 1994).
Substrates north of Umtanum Ridge along the Columbia River are composed chiefly of boulders, cobble,
gravels and sand from the Pleistocene outburst floods (Reidel and Fecht 1994), and is generally mantled with
Quaternary alluvium (Goff 1981).

2. VEGETATION OF THE MCGEE RANCH–RIVERLANDS UNIT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
12
LAND USE HISTORY
Overgrazing by livestock occurred in the area as early as 1880-81 (Parker 1979). This long-term grazing
pressure undoubtedly suppressed the preferred grasses and promoted increased density of shrubs, a condition
that is probably still evident in some of the oldest unburned portions on the site. The study area has two areas
that were under early cultivation and development. As early as 1892, settlers along the Columbia River
developed natural springs, dug wells, or pumped irrigation water from the river using gasoline engines.
Artesian wells near the McGee Ranch on the south side of Umtanum Ridge provided irrigation water for
agriculture and a number of home sites prior to 1943, when the site was acquisitioned by the Federal
Government for the Hanford Site.
In the early 1950s, several anti-aircraft artillery batteries were established around the Hanford Site’s nuclear
production facilities. One of these batteries was located on Umtanum Ridge in the eastern portion of the study
area. Although the approximately 20-acre facility was decommissioned and razed during the early 1960s, its
footprint can still be seen near the east end of the study area. Activities surrounding this site are presumably
responsible for some ground disturbances along the ridge. In the lowland north of Umtanum Ridge, a railway
depot was located in the Riverlands Area, along the Milwaukee Road right of way. The depot was dismantled
in 1990 and the railway tracks removed. The Bonneville Power Administration’s Midway Substation is
located nearby. A townsite where substation workers and their families were housed was located near the
substation, just downslope from Juniper Springs. Several power transmission lines cross the area. Roads,
many of which are associated with powerline construction and maintenance, provide access to much of the
site. The southern portion of the unit is closed to the public, and vehicle access is regulated with locked gates.
The Riverlands portion of the site near the Columbia River is open to public access. Some of the primitive
roads in this section are closed to vehicles.
Livestock grazing has presumably been prohibited on the unit since about 1950, although active enforcement
was apparently sporadic until the 1970s. Incidences of trespass grazing by sheep continue to be reported
occasionally along the western edge of the site.
Methods
Mapping methodology was similar to that described in Easterly and Salstrom (1997, 1999,2002a, 2002b).
Prior to beginning work in the field, a preliminary assessment of vegetation polygons was made using aerial
photos. These photos were extremely useful in discerning large-scale vegetation patterns and developing a
preliminary map of polygon distributions, but they were generally not useful in delineating changes in shrub
or grass species. In addition, portions of the study area burned in 1996, after the most recent aerial photos
were taken. Extensive ground surveys were done between May and September 2002 to adjust and refine
preliminary polygon boundaries and to detect plant community types that were beneath the resolution of the
aerial photos. Polygon boundaries were drawn to reflect the sinuosity of plant community boundaries as much
as possible.
Distributions of priority species (Table 2.1) were used to delineate polygon boundaries. Boundaries were
drawn to reflect changes in cover of priority species when trends were observed at a level that could be
mapped. Mapping units were identified by the dominant shrub and grass species, or by the dominant grasses
where no shrubs were present. Plant community identifications were based on technical literature (Crawford
1999, Daubenmire 1970) and personal experience. Significant natural biological resources are classified as
‘elements’ of biodiversity and reported to the Washinton Natural Heritage Program. Each polygon that
represented an element identified in the state’s Natural Heritage Plan (WNHP 2003, 1999) was evaluated for
its conservation potential based on a ranking of the plant community’s condition, size, and factors in the

2. VEGETATION OF THE MCGEE RANCH–RIVERLANDS UNIT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
13
surrounding landscape. Community condition was evaluated in terms of the cover and condition of
microbiotic crusts, cover of non-native and disturbance-oriented plant species, and the similarity of the
community’s composition to published accounts of the vegetation type. Criteria for community size relate to
the community’s potential long-term viablility; these criteria vary with the type of system being evaluated and
with other factors. Landscape factors include the proximity of areas or corridors of disturbance, the presence
of disturbance vectors such as grazing or development, and other factors (NatureServe 2002).
TAXONOMIC NOMENCLATURE
Taxonomic nomenclature follows Hitchcock and Cronquist (1973), with three exceptions. Updated taxonomy
is used in referring to Atriplex spinosa (= Grayia spinosa), Agropyron spicatum (= Pseudoroegneria spicata),
and for the Poa secunda complex, which formerly included Poa nevadensis, Poa sandbergii, and Poa
scabrella, among others.
Table 2.1. Partial list of priority species used to define polygon boundaries and generate mapping-unit names.
Common Name Scientific Name
Shrubs
stiff sagebrush Artemisia rigida
Wyoming big sagebrush Artemisia tridentata ssp. wyomingensis
Douglas’ desert buckwheat Eriogonum douglasii
snow buckwheat Eriogonum niveum
rock buckwheat Eriogonum sphaerocephalum
thyme-leaved desert buckwheat Eriogonum thymoides
winterfat Eurotia lanata
spiny hopsage Grayia spinosa
bitterbrush Purshia tridentata
purple sage Salvia dorrii
Grasses
crested wheatgrass Agropyron cristatum
thickspike wheatgrass Agropyron dasytachyum
cheatgrass Bromus tectorum
alkali saltgrass Distichlis spicata
Great Basin wildrye Elymus cinereus
bulbous bluegrass Poa bulbosa
Sandgerg’s bluegrass Poa secunda
bluebunch wheatgrass Pseudoroegnaria spicata
sand dropseed Sporobolus cryptandrus
needle-and-thread Stipa comata

2. VEGETATION OF THE MCGEE RANCH–RIVERLANDS UNIT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
14
Results and Discussion
Topography, geology, fire history, and land-use history have combined to create a complex mosaic of
vegetation types within the McGee Ranch–Riverlands Unit of the Hanford Reach National Monument. This
survey delineated 245 polygons of existing vegetation, representing 17 major vegetation types on the unit
(Fig. 2.1; Table 2.2). The greatest diversity in vegetation types occurred along the crest of Umtanum Ridge
and adjacent areas. The gentle slopes down to the Cold Creek Valley south of Umtanum Ridge, along with the
Riverlands area to the north, tended to have relatively more uniform vegetation, as reflected by the fewer,
larger polygons identified there.
Table 2.2. Coverage of existing plant community types on the McGee Ranch–Riverlands Unit, Hanford
Reach National Monument. Areas covered do not include riparian and rivershore communities of the
Columbia River previously mapped by Salstrom and Easterly (1995) and Easterly and Salstrom (2001).
Plant Community Number of Polygons
Total Acreage
Mapped
WNHP Protection
Priority Status,
Columbia Plateau
bluebunch wheatgrass 13 329 1
cheatgrass 2 12
crested wheatgrass 1 14
big sagebrush/bluebunch wheatgrass 19 253 3
big sagebrush/needle-and-thread 2 12 1
big sagebrush/Great Basin wildrye 2 4
big sagebrush/alkali saltgrass 2 13
big sagebrush/Sandberg’s bluegrass 97 3409
big sagebrush – stiff sagebrush/bluebunch
wheatgrass
3 119
needle-and-thread 4 307 1
purple sage/bluebunch wheatgrass 1 34
Sandberg’s bluegrass 76 3975
stiff sagebrush/bluebunch wheatgrass 2 27
stiff sagebrush/sandberg’s bluegrass 14 120 3
winterfat/needle-and-thread – Sandberg’s
bluegrass
3 338 2
winterfat/bluebunch wheatgrass 2 45
Facilities 2 51
Total 245 9060

2. VEGETATION OF THE MCGEE RANCH–RIVERLANDS UNIT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
15
Fig. 2.1. Existing vegetation of the McGee Ranch–Riverlands Unit, Hanford Reach National Monument,
2002.

2. VEGETATION OF THE MCGEE RANCH–RIVERLANDS UNIT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
16

2. VEGETATION OF THE MCGEE RANCH–RIVERLANDS UNIT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
17
GENERAL VEGETATION DESCRIPTION
The historic floodplain of the Columbia River north of Umtanum Ridge is gravel and cobble with occasional
sandy areas and some secondary flood channels. The dominant cover type in this area is Wyoming big
sagebrush (Artemisia tridentata ssp. wyomingensis)/Sandberg’s bluegrass (Poa secunda), commonly with
spiny hopsage (Grayia spinosa) on substrate that appears to be coarser in texture and/or shallower. Snow
buckwheat (Eriogonum niveum) is common and sometimes dominant on sandy sites. The grass layer is
frequently dominated by Sandberg’s bluegrass (which is sometimes vigorous), sometimes with high densities
of cheatgrass (Bromus tectorum). Bulbous bluegrass (Poa bulbosa) replaces Sandberg’s bluegrass in some of
the most heavily disturbed areas.
Closer to the river, the vegetation grades into riparian communities mapped in previous studies (Salstrom and
Easterly 1995, Easterly and Salstrom 2001), which include thickspike wheatgrass (Agropyron dasytachyum),
creeping wildrye (Elymus triticoides), and sand dropseed (Sporobolus cryptandrus). The latter species also
occurs intermittently in some historic flood channels and along some roads. Some of the old flood channels
that were intensely disturbed (possibly historically used as livestock bedding areas) are infested with Russian
knapweed (Centaurea [= Acroptilon] repens). Diffuse knapweed (Centaurea diffusa) has colonized most
roadways in this area to some degree, as well as the surface of the old railroad bed.
Along the top of Umtanum Ridge, lithosols occur repeatedly and support stiff sagebrush (Artemisia
rigida)/Sandberg’s bluegrass with and without thyme-leaved buckwheat (Eriogonum thymoides) and
Douglas’ buckwheat (Eriogonum douglasii). While some of them burned, these lithosols generally served as
firebreaks for the 1996 fire.
On the north slope of Umtanum Ridge, substrates include basalt outcrops, lithosols, sedimentary interbeds,
and loess. On much of this area, the substrates (and accompanying vegetation) recur on a relatively small
scale and intergradations are common. Lithosols along spur ridges support stiff sagebrush/Sandberg’s
bluegrass, frequently with purple sage (Salvia dorrii) and rock buckwheat (Eriogonum sphaerocephalum).
Elsewhere, bluebunch wheatgrass (Pseudoroegneria spicata) is common, especially on soils with a loess
component. Cheatgrass is a frequent component of the vegetation on the south aspects of secondary ridges.
Needle-and-thread (Stipa comata) occurs sporadically along the slope, usually in areas with a relatively higher
percentage of sand sorted from the slack-water Pleistocene sediments. Portions of the slope, especially in the
western part of the study area, burned in 1996. There, as in most other burned sites within the study area, big
sagebrush reproduction was often abundant. Both grey and green rabbitbrush (Chrysothamnus nauseosus and
C. viscidiflorus) occur sporadically, especially on upper slopes in the burned areas where they have
resprouted. Small areas with Winterfat (Eurotia lanata) occur along the slope, apparently associated with
soils derived from the sedimentary interbed materials.
On the upper slope south of Umtanum Ridge in the western portion of the study area, winterfat/needle-and-
thread occurs on slack-water flood sediments and associated loess. Parts of this area burned in 1996, after
which the winterfat resprouted. Within this zone, needle-and-thread generally occurs intermittently, creating a
mosaic of winterfat/needle-and-thread and winterfat/Sandberg’s bluegrass. Fire eliminated most of the mature
individuals of Wyoming big sagebrush in this area. Bluebunch wheatgrass occurs with winterfat along the
western margin of the study area, a cover type that continues upslope to the west off the site. To the east and
south, the elevation drops, the substrate becomes coarser, and winterfat drops out. Needle-and-thread and
bluebunch wheatgrass continue along the ridge to the east, with the latter species becoming confined to north
aspects as the elevation continues to drop. Big sagebrush seedlings are abundant in much of the burned area.
The south flank of Umtanum Ridge burned patchily in 1996. On the lower to middle portion of the slope,
unburned sites support big sagebrush/Sandberg’s bluegrass. Spiny hopsage is frequently present at relatively
high concentrations, especially at lower elevations. Large patches of needle-and-thread occur regularly at
mid-elevations, especially on sandier sites where the shrub cover has been reduced by fire. Adjacent burned
and unburned sites often seem to indicate an inverse relationship between needle-and-thread and shrub cover

2. VEGETATION OF THE MCGEE RANCH–RIVERLANDS UNIT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
18
that is evidently not due to substrate variation. Needle-and-thread drops out at lower elevations within the
study area. As elsewhere on the site, reproduction of big sagebrush is generally abundant, although uneven, in
the burned area.
Hemishrubs such as longleaf phlox (Phlox longifolia) and a wide variety of forbs are conspicuous in many
areas. On the south flank of Umtanum Ridge, the forbs buckwheat milkvetch (Astragalus caricinus) and
hoary aster (Machaeranthera canescens) are common and sometimes abundant. Large patches of Cusick’s
sunflower (Helianthus cusickii) are also conspicuous throughout the lower south slope, usually where shrub
cover is low. Carey’s balsamroot (Balsamorhiza careyana) occurs throughout much of the entire area,
sometimes in high concentration. The unit provides habitat for rare plants such as Columbia milkvetch
(Astragalus columbianus), Piper’s daisy (Erigeron piperianus), Hoover’s desert parsley (Lomatium
tuberosum), Umtanum desert buckwheat (Eriogonum codium), and others (Soll et al. 1999).
Non-native invasive species occur sporadically throughout the area, sometimes in high concentrations.
Russian thistle (Salsola kali) occurs in areas of recent disturbance. Diffuse knapweed (Centaurea diffusa)
occurs along most roadways in the area, and in some disturbed grasslands and shublands. Old agricultural
fields have been colonized by numerous invasive species, including extensive infestations of Russian
knapweed (Centaurea [= Acroptilon] repens), whitetop (Cardaria draba), and perennial pepperweed
(Lepidium latifolium), among others.
In and around McGee Ranch on the lower south slope, the vegetation is dominated by cheatgrass (Bromus
tectorum). This is presumably a result of historic cultivation and livestock grazing, along with recurring
wildfires in recent years. Big sagebrush seedlings are present in much of the area.
VEGETATION CONDITION
Although parts of the site exhibit evidence of heavy disturbance by cultivation, fire, grazing, and invasion by
non-native species, much of the study area is in relatively good ecological condition. Disturbed areas at the
higher elevations have potential for natural recovery. At lower elevations, the potential for recovery from past
disturbances is likely slowed or reduced because of the lower productivity and resilience in these harsher
physical settings. These areas are apparently below the ecotone for needle-and –thread and bluebunch
wheatgrass, and the initial diversity was probably low relative to sites at higher elevations. Although
cheatgrass is a component of the vegetation in much of the site, it is seldom dominant above the low elevation
areas.
In some portions of the site, dense shrub cover likely reflects a response to historical overgrazing. These high
shrub densities have been reduced or removed in some areas as a result of the 1996 wildfire. It is not yet clear
to what extent those areas will recover the perennial bunchgrass component of the vegetation, but initial
observations frequently indicate higher bunchgrass cover where the shrub cover has been reduced or removed,
especially at middle to upper elevations. The structure of the communities will continue to be modified as the
shrub seedlings present at many of these sites come to maturity.
NATURAL HERITAGE ELEMENT OCCURRENCES
Vegetation polygons that meet minimum standards for size, condition, and landscape factors represent areas
of significant conservation value, termed elements of biodiversity, and will be reported to the Washington
Natural Heritage Program. The extensive, unconverted, natural landscape of much of the McGee Ranch–
Riverlands Unit, some of which is managed for conservation, gives a high landscape rank for all elements that
can be identified on the site. Elements are based on potential native plant communities: the existing “climax”
vegetation or the climax vegetation projected to occur if the site is left undisturbed. In some cases ecosystem
components, such as a complete shrub layer, may be missing at present, but may be expected to develop in the
absence of outside disturbance.

2. VEGETATION OF THE MCGEE RANCH–RIVERLANDS UNIT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
19
Fig. 2.2. Proposed Natural Heritage Element Occurrences on the McGee Ranch–Riverlands Unit, Hanford
Reach National Monument.

2. VEGETATION OF THE MCGEE RANCH–RIVERLANDS UNIT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
20

2. VEGETATION OF THE MCGEE RANCH–RIVERLANDS UNIT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
21
Elements that meet minimum size standards for regional importance are big sagebrush/needle-and-thread
(Artemisia tridentata/Stipa comata), big sagebrush/bluebunch wheatgrass (Artemisia
tridentata/Pseudoroegneria spicata), stiff sagebrush/Sandberg’s bluegrass (Artemisia rigida/Poa secunda),
big sagebrush-spiny hopsage/Sandberg’s bluegrass (Artemisia tridentata-Grayia spinosa/Poa secunda), and
winterfat/needle-and-thread – Sandberg’s bluegrass (Eurotia lanata/Stipa comata-Poa secunda; Fig. 2.2,
Table 2.3). Many of these elements occur within a landscape mosaic rather than as discrete polygons.
Proposed element occurrences on the McGee Ranch–Riverlands Unit are presented in Table 2. Letter ranks
are assigned on a scale from A to F where A = highest or most favorable quality and F = the lowest or least
favorable quality (NatureServe 2002). All elements large enough to meet size criteria for element occurrences
will be considered eligible for entry into the WNHP Information System. Two of the elements mentioned
above are more specific than those currently in the Natural Heritage system. Big sagebrush-spiny
hopsage/Sandberg’s bluegrass is a subset of big sagebrush/Sandberg’s bluegrass, and winterfat/needle-and-
thread – Sandberg’s bluegrass is a subset of winterfat/Sandberg’s bluegrass. In addition, some of the polygons
on the north slope of Umtanum Ridge represent vegetation that is transitional between big
sagebrush/bluebunch wheatgrass and stiff sagebrush/Sandberg’s bluegrass, often including rock buckwheat
(Eriogonum sphaerocephalum) and purple sage (Salvia dorrii). These polygons are included in the records for
big sagebrush/bluebunch wheatgrass and stiff sagebrush/Sandberg’s bluegrass, depending on the community
type to which it was most similar.
Table 2.3. Ecosystem Element Occurrences on the McGee Ranch–Riverlands Unit, Hanford Reach National
Monument, with tentatively assigned ranks. See text for more complete explanation.
Element
Landscape
Rank
Size
Rank
Condition
Rank
Overall
Rank
Acreage
Total
big sagebrush – spiny hopsage/Sandberg’s bluegrass A B BC B 1483
big sagebrush/bluebunch wheatgrass ACB C B 830
big sagebrush/needle-and-thread ACB CB B 394
winterfat/needle-and-thread – Sandberg’s bluegrass ACB CB B 401
stiff sagebrush/Sandberg’s bluegrass A C CD BC 151
Management Recommendations
Plant community element occurrences should be managed to conserve the values of the natural resource. Soil
disturbance, in particular, should be avoided in these areas.
The entire site is susceptible to recurring wildfire. Several of the recent fires in the area were human-caused,
and most originated from vehicles. Regardless of the source of ignition, the frequency, severity, and extent of
wildfires in the Columbia Basin have increased in recent years, as they have elsewhere throughout the arid
West, in reponse to increasing abundance of cheatgrass and other invasive species (USFS 2001, Brooks and
Pyke 2001, Whisenent 1990, Young and Evans 1985, 1978). To reduce the risk of unintended ignition,
highway rights-of-way in the area should be maintained free of weeds and fuels with controlled fires or other
means compatible with management objectives. Firebreaks could be maintained along some secondary roads
within the site as well. All vehicles with back-road access should be equipped with a fire extinguisher and
shovel, and drivers should be informed of fire-prevention behavior.
Several areas within the study site are infested with noxious weeds, including large infestations of diffuse
knapweed and Russian knapweed, along with some yellow starthistle. Successful treatment of these
infestations is likely to require many years of effort and should begin as quickly as possible. Roads through
untreated areas should be closed to vehicles during periods of seed dispersal.

2. VEGETATION OF THE MCGEE RANCH–RIVERLANDS UNIT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
22

BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
23
3. Biological Soil Crusts of the Hanford Reach National
Monument
Terry T. McIntosh
Introduction
In most shrub-steppe and grassland plant communities of the Intermountain West, thin crusts of living
organisms occupy the soil surface in the interspaces between widely spaced vascular plants. Easily
overlooked by the casual observer, these biological soil crusts, also known as cryptogamic crusts or
microbiotic crusts, perform important ecological functions and are an important component of the biodiversity
of arid lands. The following section presents the results of a study of the lichens and bryophytes of the
biological soil crusts in the Hanford Reach National Monument conducted during 2002–2003. Full details are
presented in McIntosh (2003).
The primary objectives of this study were as follows:
• To expand upon previous surveys of the biodiversity of the lichens and bryophytes of the Hanford
Site. While the microbiotic crusts of shrub-steppe and grassland habitats were the primary focus of
this study, lichens and bryophytes in other habitats, including rock outcrops and talus, shrub and tree
surfaces, and wetlands, were also investigated.
• To examine relationships between the distribution of lichens and bryophytes of the biological soil
crusts and major vascular plant communities.
• To examine relationships between the distribution of lichens and bryophytes of the biological soil
crusts and readily measurable environmental variables.
BIOLOGICAL SOIL CRUSTS: COMPOSITION AND FUNCTION
Biological soil crusts are complex groupings of organisms that occupy soil surfaces in many arid and semi-
arid landscapes (Belnap et al. 2001, Ponzetti 2000). The dominant organisms that comprise biological soil
crusts are lichens, bryophytes (including mosses as well as a few liverworts), single-celled algae, and
cyanobacteria. These organisms are intermixed with fungal hyphae, algae, plant roots, litter, and soil.
Biological crusts can be extremely diverse: More than 10 species of organisms can be present on as little as 2
cm of soil. As a unit, these assemblages are often compact and fragile.
Biological crusts perform a number of ecologically important roles that contribute to ecosystem health and
integrity (Belnap et al. 2001, Ponzetti 2000, Evans and Johansen 1999). An example is their function in
respect to soil stability. Open soils are often in constant movement, as particles are displaced by wind and
water. As a biological crust develops, the soil stabilizes and soil displacement is reduced or eliminated,
mainly due to the binding of soil particles by the various crust organisms (Belnap and Gardner 1993, Schulten
1985). The complex microtopography of mature biological crusts creates a boundary of still air at its surface
which further protects it and the underlying soil from wind erosion (Eldridge and Kinnell 1997, Neuman and
Maxwell 1999, Lehrsch et al. 1988).

3. BIOLOGICAL SOIL CRUSTS OF THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
24
The presence of a biological soil crust can influence the surface hydrology of a site. In many sites, it appears
that infiltration rates are increased with the presence of a crust, although this depends on a number of factors,
including soil type, crust composition, and climate (Ponzetti 2000, Eldridge 1993). The presence of intact
biological crusts may also inhibit the establishment of cheatgrass (Bromus tectorum) and other invasive
species (Belnap et al. 2001, Kaltenecker et al. 1999).
Lichens, bryophytes, cyanobacteria, and green algae in the crust fix atmospheric carbon, contributing to the
overall productivity of a plant community. Free-living cyanobacteria and many lichens in the crust are
capable of fixing atmospheric nitrogen, which is subsequently released into the soil and used by vascular
plants and fungi, contributing to enhanced productivity (Belnap et al. 2001, Evans and Belnap 1999). In some
cases, vascular plants that grow in areas of well developed crust have higher accumulations of essential plant
nutrients than in sites that lack a crust (Belnap et al. 2001, Ridenour and Callaway 1997).
Most biological soil crusts are fragile and readily disturbed, with susceptibility to disruption related in part to
site factors such as soil type, local climate, the vascular plant community, and other factors (Belnap et al.
2001, Ponzetti 2000). Over the past century, most biological crusts in the Pacific Northwest have been heavily
altered and sometimes destroyed by livestock, agricultural practices, wildfire, invasive species, and off-road
vehicle use. There is evidence that the biological soil crusts in the Pacific Northwest, including those in the
Hanford area, evolved in low disturbance environments, where impacts by large herbivores and fire were
much less severe than at present.
PREVIOUS SOIL CRUST RESEARCH IN THE HANFORD AREA
Biological soil crusts have frequently been overlooked in studies of shrub-steppe vegetation, and until
recently, little research has been completed on the biological crusts of the Hanford area. McIntosh (1986)
collected bryophytes and lichens on the Fitzner-Eberhardt Arid Lands Ecology (ALE) Reserve in 1981, before
several landscape-scale wildfires had swept the site. The lichens in these collections are still awaiting
identification. Johansen et al. (1993) studied the effects of fire on the algal and cyanobacterial components of
biological soil crusts in the area.
The first study of lichens and bryophytes in the biological soil crusts at Hanford was completed in 1998. Link
et al. (2000, summarized in Soll et al. 1999) collected lichens and bryophytes from 13 locations across the
Hanford Site, including six locations in the Central Hanford area. They reported 29 lichen and six moss
species. Six of the lichen species that they collected were unidentified at the time of their survey, but since
then, two have been described as new species of Trapeliopsis (McCune et al. 2002). Five of their lichen
collections were reported as new to Washington state.
Ponzetti et al. (2000) completed an extensive grazing management-related ecological study of the biological
crust communities in the Horse Heaven Hills, in Benton County south of the Yakima River. Their research
identified more than 50 lichen species and 11 bryophytes in the biological crusts in this area. Another 50 or
more species of lichens were identified from rock surfaces or on wood or bark.
The rare lichen species Texosporium sancto-jacobi (McCune and Rosentreter 1992) is the subject of a long-
term study in the region by Von Reis and her students at Columbia Basin College. Although this species has
not yet been found on the Monument, there is potential for it to be present (J. von Reis pers. comm.).
CONSTRAINTS ON THE IDENTIFICATION OF LICHENS AND BRYOPHYTES
Lichens and bryophytes are inherently difficult to identify with confidence in field studies. Most species of
arid land lichens and bryophytes are very small in stature. Lichen thalli and apothecia and the gametophyte
stage of many mosses often range from only 1 mm to 2 mm in size at maturity. These organisms are often
difficult to distinguish in the field and usually must be collected in order to confirm identifications. In the

3. BIOLOGICAL SOIL CRUSTS OF THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
25
laboratory their small stature leads to difficulties in identification, even with the use of microscopes. Chemical
testing, leaf cross-sections, spore analysis, and other methods must frequently be employed before conclusive
identifications can be made.
Few taxonomic keys and little illustrative material is available for most groups of these taxa. These groups of
organisms have comparatively few specialists who fully understand specific genera, let alone the full suite of
taxa that are present in a geographic region. Consequently, collections must often be sent to experts far away,
sometimes overseas, before identifications can be confirmed. Bryophyte and, especially, lichen taxonomies
are far from resolved. There can be conflicts in species concepts, and identical specimens may be identified
differently by different experts.
Methods
Field work was conducted between August 2002 and April 2003. One hundred and eighteen microbiotic
biodiversity sites were established across the Monument. Sites were chosen based primarily on richness of the
microflora and/or on the presence of an unusual habitat. At each site, all identifiable lichen and bryophyte
species were listed in the field, and collections were made for later identification. General ecological
observations, including vegetation type, were recorded at each site.
The primary focus of biodiversity surveys was on soil crust taxa; however, additional collections were made
on rock outcrops, talus, rocks, and stones, and on the branches and bark of shrubs and trees. Two collections
were made in wetland habitats: one site along the Hanford Reach of the Columbia River, and another in a
seepage area in the southern portion of the Wahluke Unit.
Fifteen sites were selected for community sampling of biological soil crusts (Table 3.1, Fig. 3.1). Sites were
chosen based on the distinct and well-developed character of the crust communities, following an extensive
reconnaissance of Monument lands. All of the community sampling sites exhibit a more or less irregular
mosaic of biological crusts, with patches of open soil alternating with patches of crust, mainly as a result of
past or ongoing disturbance.
Table 3.1. Biological soil crust community sampling sites, 2002–2003.
Site Management Unit UTM Coordinates
(NAD27)
Elevation (Ft.) Soil Type Slope Aspect
1ALE 300789 / 5140760 3520 stony loam 20o–30oW–SW
2ALE 306215 / 5139957 1140 sandy loam 0o0
3Saddle Mountain 293688 / 5172363 787 loamy sand 5o SE
4Saddle Mountain 293688 / 5172363 787 loamy sand 5o SE
5Saddle Mountain 302951 / 5176023 432 sandy loam 0o0
6ALE 296714 / 5146925 1618 sandy loam 5o–10oSW
7ALE 291354 / 5150809 946 sandy loam 0o–5o 0–NW
8McGee-Riverlands 286889 / 5165518 1362 sandy loam 5o N
9ALE 288469 / 5152773 810 sandy loam 0o 0
10 ALE 290797 / 5158731 782 sandy loam 0o0
11 McGee-Riverlands 288564 / 5164812 1053 loamy sand 0o0
12 McGee-Riverlands 288614 / 5165458 1040 sandy loam 0o–5o 0–N
13 Saddle Mountain 289687 / 5169108 454 loamy sand 0o0
14 Saddle Mountain 297146 / 5177298 640 sandy loam 0o –5o0–N
15 Wahluke 321208 / 5160233 400 loamy sand 0o0

3. BIOLOGICAL SOIL CRUSTS OF THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
26
The initial intent of the study was to select sites representative of the major vascular plant communities and to
sample associated crust assemblages. Owing to the disturbed condition of much of the Monument, however, it
was difficult to find clearly defined vascular plant communities with sufficiently developed crusts. Therefore,
the site selection protocol was modified to emphasize the better-quality crust assemblages, and the associated
vascular plant communities were described following site selection.
A single 20 m transect was laid out in the most homogeneous part of the site and through the most
representative part of the crust community, avoiding shrubs when possible. The transect was placed parallel to
a slope, if present. At Site 4 this protocol was altered; this plot was installed to sample undisturbed areas
under shrubs along a 80 m transect in order to compare the microbiotic species there with the open crust
areas.
Twenty 20 x 20 cm microplots were sampled at 1m intervals along each transect (Belnap et al. 2001).
Microplots that fell on heavily disturbed locations were moved to the opposite side of the transect, or 40 cm
along the transect if the opposite side was also disturbed.
Cover of mineral soil, litter, total crust, vascular plant bases, stones, and individual microbiotic species or
species groups were estimated using a cover class scale (Ponzetti 2000). In most sites, there were juvenile or
colonizing microbiotic taxa that were lumped into unidentified lichen (UL, including lichens and
cyanobacteria) or unidentified bryophyte (UB) categories. In all cases, greater than 90% of all species present
along or near the transect were captured in the sampling plots.
Small collections of representative species were collected from many of the plots in order to confirm
identifications later and to ensure that smaller taxa had not been overlooked.
Each site was photographed, and general habitat conditions, including surface soil characteristics, slope,
aspect, and other observations, were recorded. Coordinates were recorded at the origin of each transect using
a portable GPS device.
Surface soil samples were collected from each site near the center of the transect. Samples were taken from
areas of open soil so that the crust was not disturbed. Conductivity and pH were assessed for all samples,
following the protocols outlined by Ponzetti (2000). Unfortunately, soil pH and electro-conductivity values
varied considerably within sites and could not be used in the site-based community analysis. Soil texture was
estimated by hand for the purpose of site characterization.
Community data were analyzed using non-metric multidimensional scaling (NMS). NMS is an ordination
method designed to produce a graphical representation of a set of data points, in this case representing species
and sites, based on their similarity or dissimilarity (McCune and Grace 2002, Kenkel and Orloci 1986).
Distance in the ordination diagram is roughly proportional to the dissimilarity between sampling units
calculated from the correlation values of their species composition data. The goodness of fit of the ordination
dimensions to the actual calculated distance matrix is represented by a stress value, with smaller stress values
representing a better fit than larger values. Only confirmed lichen and bryophyte species and genera (45 taxa
in total) were used in the analysis.
Unlike other commonly used ordination methods in ecology, NMS does not require assumptions of linearity
or unimodality of species along environmental gradients. Thus, NMS is often considered the method of
choice where species distributions are patchy and discontinuous (De Grandpré et al., 2000, Kenkel and Orloci
1986, Pyke et al. 2001, Qian et al. 2003), as in this data set. The ordination axes generated by NMS represent
the optimum number of dimensions for summarizing the data and do not necessarily account for sequentially
declining proportions of variation in the data as is the case with other ordination methods. For this reason,
once the final multidimensional solution has been determined for a given dataset, the selection of axis
combinations to use for graphic representation is that which leads to the clearest overall interpretation. The
NMS was run in autopilot mode using PC-ORD version 4.17 (McCune and Mefford 1999).

3. BIOLOGICAL SOIL CRUSTS OF THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
27
Fig. 3.1. Locations of microbiotic crust community sampling sites, Hanford Reach National Monument,
2002–2003.

3. BIOLOGICAL SOIL CRUSTS OF THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
28

3. BIOLOGICAL SOIL CRUSTS OF THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
29
TAXONOMY AND NOMENCLATURE
Collections of lichens and bryophytes were made at both biodiversity and community sites for later
identification in the laboratory. In total, over 2000 individual specimens were examined during this project.
While many taxa were identified, a number of specimens were too undeveloped or too small to identify. Other
taxa could be identified only to the genus level and are still awaiting identification to the species level.
There is no single comprehensive reference available for arid land lichens. Goward et al. (1994), McCune and
Rosentreter (1995), and Brodo et al. (2001) proved to be useful general guides. There are more references
available for the bryophytes, including Flowers (1973), Lawton (1971), McIntosh (1986, 1989), Rossman
(1977), and some of the recently published works for the Bryophyte Flora of North America Project (BFNA
2003). J. Ponzetti, B. McCune, and T. Goward assisted with the identification of lichens. Bryophytes were
identified by the author, and some specimens have been sent away for confirmation or identification by other
experts. Herbaria at Oregon State University, at the University of British Columbia, and the private herbaria
of T. Goward and J. Ponzetti were also helpful in the identification of lichens.
Vascular plant taxonomy follows Hitchcock and Cronquist (1973).
At this time, an increasing number of arid land lichen and bryophyte taxa are under revision and many generic
names are in flux. In most cases, the taxonomic names that are used here are the more familiar traditional
names, with a few exceptions. Following the work of Zander (1993), the moss genus Syntrichia is used here
instead of the more familiar Tortula for the larger and coarser species of this group. Also, some researchers
consider Syntrichia ruralis var. papillosissima to be a separate species, but this taxon is kept as a variety here,
pending results of the ongoing research of Chan (2003).
Representative specimens of all species, once identified, will be packaged, labeled, and sent to the U.S. Fish
and Wildlife offices in Hanford. Extra specimens will be housed at Oregon State University, the University of
British Columbia, and, for the bryophytes, at the University of Washington, a request of Judith Harpel, a rare
plant specialist for Washington state.
Vascular plant nomenclature follows Hitchcock and Cronquist (1973).
Results
LICHENS
This study found 54 lichen taxa growing as part of the terrestrial soil crust community (Table 3.2). Thirty-six
of these taxa have been identified to species, while the identifications of the remainder are conditional at
present. Of these, four taxa have tentative species identifications and14 have been identified to the genus only.
Twenty-six lichens are common and widespread to locally common across the Monument, and the remaining
taxa are uncommon to rare.
In addition to the terrestrial lichens, at least 26 taxa of saxicolous lichens were collected growing on rock
outcrops, rocks, or stones (Table 3.3). Most collections of saxicolous lichens have been identified to genus
only; five taxa are still of unknown identity. Not enough information is available to assess the distributions of
saxicolous lichens.
Eleven lichen taxa are epiphytic on bark of shrubs and trees (Table 3.4). Most have been identified to genus,
with species identification pending. Most of the epiphytic lichens listed in Table 3.4 appear to be relatively
widespread, at least where sagebrush is present.
Four lichen species were found on two substrata. Lecanora muralis and an unknown, Xanthoria-like lichen
are both primarily saxicolous, but are also found on soil. Physconia enteroxantha is found commonly on both
bark and soil, and Candelaria concolor, primarily epiphytic, was occasionally found on soil.

3. BIOLOGICAL SOIL CRUSTS OF THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
30
Table 3.2. Terrestrial Lichens on the Hanford Reach National Monument, 2002–2003. X = taxa identified in
2002 (this study) and 1998 (Link et al. 2000). Numbers in parentheses indicate estimated number of species
collected from that genus in 2002. General distribution of the taxa as observed in 2002 is indicated as follows:
C = common and widespread; L = locally common, but not widespread; U = uncommon; R = rare.
Taxon 2002 1998 Distribution
Acarospora schleicheri X X L
Amandinea punctata X X L
Arthonia glebosa X X C
Aspicilia filiformis X X U
Aspicilia reptans X X L
Aspicilia spp. (2) X X R
Aspicilia cf. terrestrialis X R
Caloplaca jungermanniae X X L
Caloplaca stillicidiorum X L
Caloplaca tominii X X C
Caloplaca sp. X R
Candelaria concolor X R
Candelariella terrigena X X L
Catapyrenium sp. X R
Cladonia cariosa XC–U
Cladonia fimbriata X
Cladonia cf. pyxidata X X C–U
Cladonia sp. (unknown
number)
X L
Collema cf. coccophorum X U
Collema tenax X X C
Collema spp. (2) XU–R
Diploschistes muscorum X X C
Endocarpon pusillum X X L
Lecanora sp. X R
Lecanora hagenii X X L
Lecanora muralis X X L
Lecanora zosteri X U
Lecidiella stigmatea X U
Lepraria sp. X R
Leptochidium albociliatum X X L
Leptogium lichenoides X X C
Leptogium spp. (2) X R
(Table continues)

3. BIOLOGICAL SOIL CRUSTS OF THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
31
Table 3.2 (continued).
Taxon 2002 1998 Distribution
Massalongia carnosa X X U
Megaspora verrucosa X L
Mycobilimbia lobulata X R
Peltigera rufescens X X R
Phaeorrhiza sareptana X L
Physconia enteroxantha X X C
Physconia isidiigera X X U
Physconia muscigena X R
Placidium sp. X R
Placynthiella cf. uliginosa X X C
Psora cerebriformis X U
Psora decipiens X R
Psora globifera X X L
Psora luridella X X U–R
Psora montana X X L
Toninia sedifolia X R
Trapeliopsis bisorediata X X L
Trapeliopsis sp. (possibly T.
californica)
X R
Trapeliopsis steppica X X L
possibly Xanthoria sp. X R

3. BIOLOGICAL SOIL CRUSTS OF THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
32
Table 3.3. Saxicolous lichens on the Hanford Reach National Monument, 2002–2003. Question marks (?)
indicate taxonomic uncertainty. Figures in parentheses indicate estimated number of species collected in that
genus.
Taxon Taxon
Acarospora cf. fuscata ?Lobothallia sp.
Acarospora sp. Melania cf. disjuncta
Aspicilia cf. calcarea Melania sp.
Aspicilia cf. contorta Neofuscelia sp.
Aspicilia sp. Rhizocarpon sp.
Caloplaca sp. Rhizoplaca peltata
Candelariella cf. vitellina Rhizoplaca sp.
Endocarpon cf. pulvinatum ?Sarcogyne sp.
Lecanora cf. garovaglii Umbillicaria cf. arctica
Lecanora muralis Umbillicaria spp. (2)
Lecanora cf. rupicola ?Verrucaria sp.
Lecanora sp. Xanthoria sp.*
Lecidia atrobrunnea Unknown spp. (2–5)
Lecidia cf. tessellata
Table 3.4. Epiphytic lichens on the Hanford Reach National Monument, 2002–2003. Question marks (?)
indicate taxonomic uncertainty. Figures in parentheses indicate estimated number of species collected in that
genus.
Taxon Taxon
Candelaria concolor Physcia sp.
?Cyphelium tigillare Physconia enteroxantha
Lecanora cf. piniperda Xanthoria spp. (2)
Leptogium sp. Unknown spp. (2)
Melanelia sp.

3. BIOLOGICAL SOIL CRUSTS OF THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
33
BRYOPHYTES
At least 35 bryophyte taxa, all mosses, were found during this survey (Table 3.5). Twenty-eight species
identifications have been confirmed, and seven have been identified to genus only. Twenty-four of the moss
species are associated principally with soil crusts. Five species are principally saxicolous, although two of
these species, Grimmia alpestris and G. trichophylla, are also found on some crusts with finer soils, and one
species, Grimmia anodon, on the edges of silt-rich cliffs. Five species are associated with wetland habitats.
Table 3.5. Bryophytes on the Hanford Reach National Monument, 2002–2003. Question marks (?) indicate
taxonomic uncertainty. Figures in parentheses indicate estimated number of species collected in that genus.
Habitat codes are as follows: C = soil crust, R = rock or stones, W = wetland. General distribution of the taxa
is indicated as follows: C = common and widespread; L = locally common, but not widespread; U =
uncommon; R = rare.
Taxon Habitat Code Distribution
Aloina bifrons C L
Aloina cf. rigida C R
Amblystegium sp. W R
Anacolia mensiesii R R
Barbula sp. C R
Bryoerythrophyllum columbianum C C
Bryum argenteum C L
Bryum cf. caespiticium C C
Bryum sp. C C
?Calliergon sp. W R
Ceratodon purpureus C C
Crossidium seriatum C R
Didymodon brachyphyllus C U
Didymodon cf. nevadensis C R
Didymodon tophaceus W R
Didymodon vinealis C L
Didymodon spp. (2) C U
Drepanocladus aduncus W R
Encalypta rhaptocarpa C U
Funaria hygrometrica W R
Grimmia alpestris R/C U–R
Grimmia anodon R/C R
Grimmia ovalis R U
Grimmia trichophylla R/C U
Phascum cuspidatum C R
Pseudocrossidium obtusulum C L
Pterygoneurum ovatum C U
Pterygoneurum subsessile C R
Syntrichia caninervis C C
Syntrichia princeps C L
Syntrichia ruralis C C
Syntrichia ruralis var. papillosissima C C
Tortula brevipes C C
Trichostomopsis australasiae C C

3. BIOLOGICAL SOIL CRUSTS OF THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
34
COMMUNITY ANALYSES
NMS ordination resulted in a three-dimensional solution that explained 93% of the variance in the microbiotic
soil crust community data (Table 3.6) and minimized stress in the ordination (Table 3.7). Of the three axes of
the solution, Axis 1 (59%) and Axis 3 (30%) explained the greatest proportion of the variation (Table 3.6).
Axes 1 and 3 are presented in the ordination diagram (Fig. 3.2).
In the diagram, distances between the sample units approximate similarity or dissimilarity in species
composition (McCune and Grace 2002), thus S5, S12, S13, and S14 have similar species assemblages but are
dissimilar to S11, and still more dissimilar to S2. Based on the results of the ordination, several sites or groups
of sites can be distinguished:
• Group 1 (Sites 2, 6, 7, and 9). Group 1 includes four sites on silt loam soils of the Arid Lands
Ecology (ALE) Reserve. The sites have similar vascular plant assemblages: herb layers are dominated
by bluebunch wheatgrass (Agropyron spicatum [= Pseudoroegneria spicata]) and Sandberg’s
bluegrass (Poa sandbergii [=Poa secunda]) along with associated forbs. The shub layer of Wyoming
big sagebrush (Artemisia tridentata ssp. wyomingensis) is still present in sites 7 and 9. Sites 2 and 6
have burned recently but the species composition of their biological crusts still exhibit strong
similarities to the other sites in the group.
Lichen diversity is high in this group of sites. Defining species include Acarospora schleicheri,
Arthonia glebosa, Aspicilia sp., Cladonia sp., Diploschistes muscorum, Leptochidium albociliatum,
Leptogium cf. lichenoides, and Trapeliopsis bisorediata and T. steppica. The sites exhibit relatively
high cover of mosses, with Bryoerythrophyllum columbianum, Aloina bifrons, Syntrichia caninervis,
and S. ruralis usually present.
Table 3.6. Proportion of species variance explained. Non-metric multidimensional scaling (NMS) ordination
of biological soil crust communities of the Hanford Reach National Monument, 2002–2003.
Table 3.7. Stress in relation to dimensionality (number of axes).
Non-metric multidimensional scaling (NMS) ordination of
biological soil crust communities of the Hanford Reach National
Monument, 2002–2003.
Stress
Axes Minimum Mean Maximum
126.969 36.169 53.513
211.446 14.647 18.028
36.178 6.300 6.772
43.860 5.215 18.360
Proportion Explained
Axis Incremental Cumulative
1.594 .594
2.042 .635
3.296 .932

3. BIOLOGICAL SOIL CRUSTS OF THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
35
Fig. 3.2. Non-metric multidimensional scaling (NMS) ordination of biological soil crust communities: triplot
of sites (▲), lichen and bryophyte taxa (+), and environmental vectors. Species codes for lichen and
bryophyte taxa are presented in Table 3.8. Environmental vectors are as follows: C = total percent cover of all
microbiotic crust; H = percent cover of herbaceous layer; L = percent cover of litter; R = percent cover of
rock and stone.
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10
S11
S12
S13
S14
S15
AS
AG
AF
As
CJ
CS
CTO
CTE
Cl
Co
DM
EP
LH
LM
LZ
LA
LL
Le
MC
MV
Pe
PS
Ph
PU PC
PG
PM
TBI
TS
AB BC
BA
Br
CP
Di
DV
ER
GT
POB
POV
SC
SP
SR
TBR
TA
L
CH
R
Axis
1
Axis
3

3. BIOLOGICAL SOIL CRUSTS OF THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
36
Table 3.8. Species codes for lichen and bryophyte taxa used in non-metric multidimensional scaling (NMS)
analysis (Fig. 3.2).
Lichens Code Bryophytes Code
Acarospora schleicheri AS Aloina bifrons AB
Arthonia glebosa AG Bryoerythrophyllum columbianum BC
Aspicilia filiformis AF Bryum argenteum BA
Aspicilia spp. As Bryum sp. Br
Caloplaca jungermaniae CJ Ceratodon purpureus CP
Caloplaca stillicidiorum CS Didymodon sp. Di
Caloplaca tominii CTO Didymodon vinealis DV
Candelariella terrigena CTE Encalypta rhaptocarpa ER
Cladonia sp. Cl Grimmia trichophylla GT
Collema sp. Co Pseudocrossidium obtusulum POB
Diploschistes muscorum DM Pterygoneurum ovatum POV
Endocarpon pusillum EP Syntrichia caninervis SC
Lecanora hagenii LH Syntrichia princeps SP
Lecanora muralis LM Syntrichia ruralis SR
Lecanora zosteri LZ Tortula brevipes TBR
Leptochidium albociliatum LA Trichostomopsis australasiae TA
Leptogium lichenoides LL
Leptogium spp. Le
Massalongia carnosa MC
Megaspora verrucosa MV
Peltigera sp. Pe
Phaeorrhiza sareptana PS
Physconia sp. Ph
Placynthiella cf. uliginosa PU
Psora cerebriformis PC
Psora globifera PG
Psora montana PM
Trapeliopsis bisorediata TBI
Trapeliopsis steppica TS

3. BIOLOGICAL SOIL CRUSTS OF THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
37
• Group 2 (Sites 3, 4, 5, 8, 11, 12, 13, 14, and 15). This is a somewhat diverse group of sites
characterized by sandy to sandy loam soils. The vascular plant communities are characterized by
moderately well-developed to well-developed shrub layers, with Wyoming big sagebrush, bitterbrush
(Purshia tridentata), and rabbitbrush (Chrysothamnus spp.) dominant on particular sites.
Characteristic grasses include needle-and-thread (Stipa comata), Indian ricegrass (Oryzopsis
hymenoides), Sandberg’s bluegrass, and, occasionally, bluebunch wheatgrass. Site 4 appears as an
outlier to this group, but represents sampling exclusively under sagebrush, in the same plant
community as, and adjacent to, Site 3
Mosses are the major defining species for this group. They include Bryum argenteum, Bryum sp.,
Ceratodon purpureus, Didymodon vinealis, Didymodon spp., Pseudocrossidium obtusulum,
Syntrichia caninervis, S. princeps, S. ruralis, Tortula brevipes, and Trichostomopsis australasiae.
Caloplaca tominii and Placynthiella cf. uliginosa are representative lichens.
• Site 1. This site on the west-facing slope near the summit of Rattlesnake Mountain is unique among
the sample sites. It is the highest elevation site in the survey, and its stony loam, regosolic soils are
distinct from the soils of the other community sampling sites.
The vascular plant community is characterized by scattered low shrubs (Eriogonum spp., Artemisia
tripartita), along with bluebunch wheatgrass (Agropyron spicatum), Sandberg’s bluegrass (Poa
sandbergii), and forbs. There is some sign that fire has burned through the site, but the effects of fire
have probably been minimized by the discontinuous distribution of vascular plants on the stony soil.
The crust here appears to be mid- to, possibly, late seral.
Characteristic crust lichen species include Caloplaca cf. stillicidiorum, Lecanora spp., Megaspora
verrucosa, Phaeorrhiza sareptana, and Physconia sp. Lecanora muralis is common on stones in the
site, and also grows on soil, especially adjacent to the stones it inhabits. Characteristic mosses
include, Encalypta rhaptocarpa and Pterygoneurum ovatum, along with Ceratodon purpureus and a
small form of Syntrichia ruralis.
• Site 10. The species composition of microbiotic crusts at site 10 is roughly intermediate between the
associations on silt loam, sand, and stony loam soils described above, as its placement near the center
of the diagram indicates. The vascular plant community of this unburned remnant of shrubland on the
ALE Reserve is characterized by big sagebrush, spiny hopsage (Grayia spinosa), and Sandberg’s
bluegrass. The soil is a sandy loam, with occasional stones. Characteristic species include Candelaria
terrigena, Endocarpon pusillum, Lecanora muralis, Leptogium sp., Massalongia carnosa, and Psora
spp. There are no bryophytes that define this group.
Sites to the right of the ordination diagram all occur on silt loam, sandy loam, or stony loam soils, all on the
ALE Reserve (Fig. 3.2). Sites to the left are located on the McGee Ranch-Riverlands, Saddle Mountain, and
Wahluke units, and exhibit sandy loam to sandy soils, suggesting a soil gradient along Axis 1.
The variable litter (L) exhibited a moderately negative correlation with both Axis 1 (r = - 0.465) and Axis 3 (r
= - 0.463; Table 3.9). All other correlations of environmental and community variables with Axis 1 tended to
be weak. Correlations of variables with Axis 3 tended to be moderate, with total herb cover (H; r = 0.655) and
total crust cover (C; r = 0.630) exhibiting the strongest correlations. Correlations of all variables with Axis 2
tended to be weak. Cover of mineral soil was the variable least correlated with any of the NMS axes and is
not displayed on the ordination diagram.

3. BIOLOGICAL SOIL CRUSTS OF THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
38
Table 3.9. Correlations of community and environmental variables with ordination axes. Non-metric
multidimensional scaling (NMS) ordination of biological soil crust communities of the Hanford Reach
National Monument, 2002–2003.
Axes
Variables 1 2 3
Crust cover 0.049 0.178 0.630
Herb cover 0.339 - 0.131 0.655
Litter - 0.465 - 0.255 - 0.463
Mineral soil 0.167 0.297 0.422
Rock & stone - 0.033 - 0.019 - 0.485
Discussion
LICHENS
This survey has shown that the Hanford Reach National Monument has a rich assemblage of lichens and
mosses that are found in shrub steppe plant communities as well as in a variety of other habitats. Over 120
taxa of lichens and mosses were found within the Monument. Due to the inherent difficulties associated with
the identification of lichens and bryophytes, a number of taxa still await identification. The number of species
is expected to increase as identification work continues. The saxicolous and epiphytic lichens, and the wetland
bryophytes reported in this study represent the first formal collections of cryptogamic taxa from these habitats
on the Monument.
At least 24 taxa have been added to the list of soil crust lichens reported on the Hanford Site (Table 3.2). The
two new species of Trapeliopsis reported by Link et al. have been recently identified as T. bisorediata and T.
steppica (McCune et al. 2002), and both were confirmed during the present survey. Twenty-two of the 23
known taxa identified by Link et al. (2000) have been confirmed, with only Cladonia fimbriata unconfirmed.
Species of Cladonia are almost always only present as squamules and are difficult to identify to species
without mature podetia (reproductive structures). There are probably more species of Cladonia present than
have been reported. Acarospora geogena, listed by Link et al. (2000), is probably best considered within the
A. schleicheri complex (B. McCune pers. comm. 2002). One lichen taxon (possibly Xanthoria) has an
uncertain generic affinity, and may represent a new lichen record for North America (T. Goward pers.
comm.).
Ponzetti et al. (2000) found a comparable number of terrestrial lichen taxa (52) from the nearby Horse Heaven
Hills area. The Horse Heaven Hills area was characterized by generally more extensive and less disturbed
crusts than those found on the Hanford Reach National Monument, as well as a wider diversity of crust
habitats. Ponzetti et al. (2000) also reported approximately 40 saxicolous lichens and some 16 epiphytic
lichens from the Horse Heaven Hills area.

3. BIOLOGICAL SOIL CRUSTS OF THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
39
BRYOPHYTES
This study has recorded more than 5 times the number of bryophyte taxa as had previosly been reported for
the Hanford Site. Four of six mosses collected earlier (Link et al. 2000) have been confirmed, and two of their
collections were found to be misidentifications. In their collections, Grimmia cf. montana is G. alpestris, and
Ceratodon purpureus is Grimmia trichophylla. Ceratodon purpureus has been confirmed for the Monument
by the present study, but G. montana has not. Ponzetti et al. (2000), focusing primarily on lichens, reported 11
bryophyte species on the Horse Heaven Hills.
Four species of bryophytes found earlier by McIntosh (1986) on the ALE Reserve in 1981 were not found
during the present survey, although they are suspected to still be present on the Monument. They include the
mosses Bryoerythrophyllum recurvirostrum, Didymodon vinealis var. luridus, and Grimmia pulvinata, and
the thallose liverwort Athalamia hyalina.
During the present survey, a number of collections were made of unusual forms of Syntrichia caninervis and
S. ruralis that do not clearly fit into familiar North American taxonomic concepts, but strongly resemble
European species. These taxa are presently under investigation at the University of British Columbia (Chan
2003), and will be sent to European authorities for confirmation.
Some of the as yet unidentified mosses may prove to be species of biogeographic significance. At least one
moss, Crossidium seriatum, a rare endemic western North American species, is new to Washington state.
COMMUNITY ANALYSES
Species that have similar ecological requirements overlap in space to form assemblages that traditionally have
been called communities. Although there has been a great deal of ecological discussion regarding vascular
plant communities, very little information is available in the literature concerning arid land bryophyte and
lichen communities.
There are some constraints to defining crust communities in the Hanford Reach National Monument, first and
foremost being the various types and degrees of disturbance and the resulting irregularity and patchiness of
the soil crusts. Most of the sites that were sampled have had fire disturbance at some level of intensity, and
some have ongoing disturbance by animals and wind. Although the crusts at most sites appear to be at an
early to middle successional stage of development, some sites have patches of crust that probably represent
late successional stages.
A minor constraint in the process of defining communities is the incomplete stage of the taxonomy and
understanding of morphological variation of many of the taxa in the Monument. While the major contributing
taxa are known, better understanding of the taxonomy of associated microbiotic species will enable
researchers to define soil crust communities more accurately.
Because of these constraints, combined with the generally early stage of exploration of the soil crusts on the
Monument, the following community identifications and descriptions remain speculative, and further research
is required before they can be more fully clarified. The following late seral soil crust communities are
postulated, based on extensive reconnaissance of the site and supported by the results of community sampling
and multivariate analysis:
1. Trapeliopsis steppica – Bryoerythrophyllum columbianum Community. This community is typical of
Group 1 sites (see Results). Additional microbiotic indicator species include the lichens: Acarospora
schleicheri, Arthonia glebosa, Aspicilia sp., Cladonia sp., Diploschistes muscorum, Leptochidium
albociliatum, Leptogium cf. lichenoides, and Trapeliopsis bisorediata. Early to mid-successional species
present in this association include the lichens: Arthonia glebosa, Cladonia sp., Diploschistes muscorum, and
Trapeliopsis bisorediata. This community was also observed during a visit to ALE in 1981 (McIntosh 1986),

3. BIOLOGICAL SOIL CRUSTS OF THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
40
when it was relatively widespread around the ALE Research Laboratories. In addition to Bryoerythrophyllum
columbianum, the mosses Aloina bifrons, Syntrichia ruralis, and Trichostomopsis australasiae, and the lichen
Diploschistes muscorum were collected there from all eight grazing control plots sampled during this visit
(McIntosh 1986).
This community develops on generally finer sandy loam and silt loam soils that predominate on the west side
of the Monument. It is associated mainly with the Wyoming big sagebrush/bluebunch wheatgrass vascular
plant community types. Although sample sites for this community type were all on relatively gentle slopes,
this community may be present on steeper slopes at higher elevations in the Rattlesnake Hills and along the
slopes of Rattlesnake Mountain.
Five of the indicator lichens for this community (Acarospora schleicheri, Arthonia glebosa, Diploschistes
muscorum, Leptochidium albociliatum, and Leptogium cf. lichenoides) are classified as non-calciphiles by
McCune and Rosentreter (1995). This suggests that the substrates on which these crusts grow are relatively
low in calcium and, following Ponzetti (2000), may also have comparatively low pH. Ponzetti (2000) found
that crust cover in the Horse Heaven Hills was generally highest on these types of soils.
2. Syntrichia spp. (in particular Syntrichia ruralis, but also S. caninervis and S. princeps) – Caloplaca
tominii Community. This moss-dominated community is characteristic of Group 2 sites (see Results). It is
common on sandier soils and thus is probably less stable and more prone to disturbance (Ponzetti 2000) than
the Trapeliopsis steppica – Bryoerythrophyllum community, with early seral species such as Bryum spp.,
Ceratodon purpureus, and Didymodon spp. common across the community and persisting even into later seral
stages. Additional indicator species include the mosses: Bryum argenteum, Caloplaca jungermanniae,
Ceratodon purpureus, Didymodon vinealis, Pseudocrossidium obtusulum, Tortula brevipes, and
Trichostomopsis australasiae, and the lichen Placynthiella cf. uliginosa.
This community develops on sandy soils with a relatively low proportion of clays and/or silts. The sands
themselves range from fine to coarsely textured. The community is associated with a variety of vascular plant
community types, including big sagebrush, bitterbrush, and rabbitbrush shrublands. Although sample sites
were primarily on gentle slopes, this community may develop on steeper slopes as well, although many of
these slopes are lacking significant crust cover.
Two of the indicator lichens for this community (Caloplaca tominii and Caloplaca jungermanniae) are
classified as calciphiles by McCune and Rosentreter (1995). This suggests, although weakly, that the
substrates on which these crusts grow are high in calcium and, following Ponzetti (2000), also have
comparatively high pH.
3. Phaeorrhiza sareptana – Lecanora spp. – Encalypta rhaptocarpa Community. This community has a
diverse assemblage of relatively small lichens, including Caloplaca and Lecanora spp., many of which
inhabit the bases of dead grasses and other litter that are common across the site. Although represented by a
single community sampling site, microbiotic species associations similar to this community were observed at
a number of other sites in the Rattlesnake Hills area and near the top of Saddle Mountain. Additional indicator
species include the lichens Candellaria terrigena, Caloplaca stillicidiorum, Megaspora verrucosa, Peltigera
sp., and Physconia sp. and the moss Pterygoneurum ovatum.
This community is characteristic of stony loam soils, and is found in low shrub (Eriogonum spp., Artemisia
tripartita)/bluebunch wheatgrass communities at higher elevations on the Monument. The generally cooler
and moister conditions at these elevations may contribute to the distinctive microbiotic flora of this
community.
One of the indicator lichens for this community (Phaeorrhiza sareptana) is classified as a calciphile by
McCune and Rosentreter (1995). This suggests, also weakly, that the substrates on which these crusts grow
may be somewhat high in calcium and, according to Ponzetti (2000), have comparatively high pH.

3. BIOLOGICAL SOIL CRUSTS OF THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
41
ENVIRONMENTAL FACTORS
Soil factors, including structure, pH, electro-conductivity, and CaCo3 availability, appear most critical in the
development and composition of biological crusts (Belnap et al. 2001, Ponzetti 2000). Understanding of the
relationship between soil chemistry and the composition of biological soil crusts is at a very early stage.
There appears to be a strong relationship between soil texture and crust composition and stability on the
Monument. Soils with finer materials, including silts, clays, and finer sands, occur most commonly on the
west side of the Monument and east of the Columbia River in the central part of the White Bluffs area. These
soils appear to favour the development of crusts with a relatively high richness and cover of lichen species.
Soils comprised of coarser materials, such as the sandier soils that predominate in the Wahluke, McGee
Ranch–Riverlands, and Saddle Mountain units, appear to have a higher richness and cover of bryophytes and
comparatively few lichens. Climatic factors, in particular heat load, and elevation also influence crust
composition (Belnap et al. 2001).
Large areas of the Monument have been heavily disturbed, particularly by fire. Disturbance, though varied in
severity and extent, was common across the entire Monument, rendering crust development patchy. The
influences of wildfire and disturbance by grazing or burrowing animals are reflected in the seral stages of the
various crusts; i.e., increasing disturbance leads to an increase in early seral taxa at any particular site, and a
generally lower seral stage of succession across the local landscape. Soil crusts across the Monument have
been affected to a greater or less degree by fire. Large areas are devoid of readily discernible crusts, although,
following rainfall, early crust development can be seen in many of these sites. The types of devastating fires
that caused this severe damage were probably nonexistent or rare in the pre-European past.
Although grazing by domestic animals has halted in the Monument, lasting effects of this activity can still be
seen in some sites. Elk also impact the soil crust to some degree over large areas of the Monument, especially
in some of the remaining small patches of Wyoming big sagebrush on the ALE Reserve where, apparently,
elk use has concentrated since the 2000 wildfire. The impacts of elk are likely not beneficial to the recovery
of soil crusts. Exclosure studies may be necessary to document these impacts.
Some areas are strongly impacted by invasive plant species, in particular cheatgrass (Bromus tectorum). In a
few areas on sandy soils, the presence of small amounts of cheatgrass may provide some mosses with a
foothold in an otherwise unstable habitat. In general, however, cheatgrass abundance is inversely related to
microbiotic soil crust cover (Ponzetti et al. 2000). Cheatgrass dominates the interspaces between perennial
vascular plants, competing with microbiotic crusts for moisture and light (Ponzetti et al. 2000) and
smothering crusts with its copious annual production of dense litter (Belnap and Philips 2001, Belnap et al.
2001). Cheatgrass infestations promote changes in other ecosystem factors such as soil chemistry, soil
nutrient regimes, and soil fauna (Evans et al. 2001, Belnap and Phillips 2001), which may impact microbiotic
crusts. Impacts of these changes on crust communities are unknown but are worth investigating.
The study of soil crust communities and their relationships to environmental factors is at a very early stage,
and the results presented here are tentative. Communities of cryptogamic organisms are difficult to define,
especially in disturbed environments (McCune and Grace 2002), and very little is known about the
community dynamics and rates of succession in soil crusts, especially for the bryophytes (Ponzetti 2000,
Ponzetti et al. 2000). The Monument provides an excellent opportunity to observe this process on a broad
scale. Knowledge of the environmental relationships of taxa and communities is often completely lacking.
Detailed studies of soil factors, in particular, are likely to yield important information in terms of species
distribution on the landscape. Such knowledge will help in the conservation and restoration of microbiotic
crust communities in the future.

3. BIOLOGICAL SOIL CRUSTS OF THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
42
Recommendations
BIODIVERSITY STUDIES
No biological inventory is ever truly complete in an area of the size and complexity of the Hanford Reach
National Monument. While most of the representative microbiotic taxa have likely been reported from large
areas of the Monument, some areas of significant cryptogam biodiversity have probably not been sampled. At
minimum, the following areas merit further investigation:
• Central Hanford, including Gable Mountain, Gable Butte, and the Hanford Dunes.
• Western portions of Rattlesnake Mountain on ALE.
• The Yakima Ridge area on ALE.
• Springs, streams, and shaded gullies of the Rattlesnake Hills north of Rattlesnake Mountain.
• Outcrops, ridges, and bluffs in the White Bluffs area. From a distance, much of this area appears to be
barren, but areas of microbiotic species richness are likely to be found, especially alongside shaded
gullies.
• Lithosol, talus, and rock outcrop communities throughout the area, at all elevations.
RESEARCH AND MONITORING
Studies of soil crust communities and their relationships to environmental factors on the Monument are at a
very early stage and much could be learned by their continuation. Monitoring changes in the soil crust
through time will contribute to a more thorough understanding of the ecological dynamics of all the
ecosystems in the Monument. Monitoring is often used to provide an objective platform for changing or
maintaining a current management practice (Rosentreter et al. 2001). However, data collected by monitoring
programs can also be applied to basic questions of conservation biology and can assist in the development and
refinement of best management practices. Rosentreter et al. (2001) and Belnap et al. (2001) provide detailed
guidance in the development of soil crust monitoring plans.
At present, no proven techniques exist for the restoration of microbiotic crusts at a landscape scale (J. Belnap
pers. comm.). Therefore, all management activities related to restoration, invasive species, and fire
management, along with general road and facilities maintenance, should be conducted in such a way as to
minimize or eliminate any adverse effect on existing quality microbiotic crust (Belnap 1994). Research into
management actions that can enhance or restore biological soil crust communities should be strongly
considered. Some promising techniques are outlined in Belnap et al. (2001).

Rare Plants

BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
45
Overview
Large-scale rare plant surveys conducted during 1994, 1995, and 1997 discovered more than 100 occurrences
of 28 rare plant taxa across the Hanford Site (Soll et al. 1999). Three of these rare taxa were entirely new to
science: Umtanum desert buckwheat (Eriogonum codium), White Bluffs bladderpod (Lesquerella
tuplashensis), and basalt milkvetch (Astragalus conjunctus var. rickardii). The results of these surveys
confirmed Hanford as a critical area for the conservation of rare shrub-steppe, riparian, and aquatic plant taxa
in Washington state.
The Biodiversity Inventory and Analysis of the Hanford Site (Soll et al. 1999) identified key areas for
additional rare plant inventory work. Little is known about the reproduction and other life history traits of
newly discovered taxa, nor of many of Hanford’s rarest plants. Demographic information is necessary to
interpret population fluctuations and guide management activities in the conservation of rare species. The
goals of rare plant studies during the 2002 field season were to increase understanding of the population
dynamics of selected rare taxa, and to extend inventories into selected special habitats. The following section
summarizes these investigations. Full details can be found in Caplow (2003).
Purpose and Scope
The design of rare plant investigations for 2002 focused on demographic studies of several rare plant species,
a targeted search for individuals and habitat for another taxon, and targeted searches in special habitat types
for rare annuals. Since low precipitation dramatically reduces the expression of the annual flora, unusually dry
conditions during winter and spring 2002 (Hanford Meteorological Station 2002) necessitated a reassessment
of this last priority. In order to utilize time and funding most efficiently, resources that had been budgeted for
this task were reallocated to other tasks within the rare plant scope of work. The revised list of objectives was
as follows:
• Objective 1. Document current status and summarize previous years’ demographic data for Rorippa
columbiae.
• Objective 2. Document current status and summarize previous years’ demographic data for
Eriogonum codium.
• Objective 3. Document current status and summarize previous years’ demographic data for
Lesquerella tuplashensis.
• Objective 4. Survey islands of the Hanford Reach of the Columbia River for occurrences or potential
habitat of Artemisia campestris subsp. borealis var. wormskioldii.

OVERVIEW
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
46

BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
47
4. Current Status of Columbia Yellowcress (Rorippa columbiae)
on the Hanford Reach
Florence E. Caplow
Introduction
Columbia yellowcress, Rorippa columbiae, is a low-growing perennial herb in the mustard family
(Brassicaceae). Columbia yellowcress is listed as a Species of Concern with the USFWS and is considered
Threatened in Washington (WNHP 1997).
The local population of Columbia yellowcress is one of 11 populations of the species, which is known from
the Hanford Reach of the Columbia River (Fig. 4.1), the lower Columbia, south-central Oregon, and the
Modoc Plateau in northeastern California. Based on fieldwork in 1982 and 1994, the Hanford Reach
population of Columbia yellowcress had been considered the species’ most vigorous known population
(Salstrom and Gehring 1994). The other ten populations supported a total of between 12,000 and 22,000
plants in 1996 (Kaye 1996).
Although the habitat of Columbia yellowcress varies across its range, there are several habitat characteristics
that all populations share: inundation for part of the year, seasonal fluctuation of water level, wet soil well
into the growing season, and open habitats with a low cover of competing vegetation. Population numbers can
fluctuate from year to year, and these fluctuations seem to be hydrologically driven (Kaye 1996). The plants
grow and reproduce in late summer and early fall, when water levels are lowest. The species is rhizomatous
and may also spread vegetatively by rooting at the nodes of aboveground stems. Stems are found in clusters,
indicating the possibility of large clones (Gehring 1994).
Methods
Two methods were used in 2002 to document the current status of Rorippa columbiae on the Hanford Reach:
1. Re-surveying of long-term monitoring plots installed by the U.S. Bureau of Land Management
(BLM) at the downstream end of the Hanford Reach.
2. Direct visual surveys of areas along the reach that once supported large numbers of R. columbiae
plants.
BLM MONITORING TRANSECTS
In 1991 the BLM installed seven transects within the Hanford reach population of R. columbiae (Fig. 4.2).
The transects are located on three islands: Homestead Island (three transects), Plow Island (three transects),
and North Forked Island (one transect). The monitoring was designed based on the protocol developed by
Janet Gehring (1992). Two-meter-wide transects were subjectively placed in areas that support R. columbiae.
Transects varied in length, depending on the spatial organization of the R. columbiae subpopulation. Within

4. CURRENT STATUS OF COLUMBIA YELLOWCRESS (RORIPPA COLUMBIAE) ON THE HANFORD REACH
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
48
each transect, subjectively chosen 2 m x 5 m macroplots were placed in 1991 within areas that supported R.
columbiae. These macroplots have been used since 1991. The number of macroplots per transect also varies.
Sixteen 0.5 m x 0.5 m microplots were placed within each macroplot in 1991. The number, height, and
reproductive status of all stems in each microplot were recorded. The transects were surveyed by BLM in
1994, 1995, 1997 (partial), 1998, and 2002. The 1997 data has not been used in this analysis, since only two
transects were surveyed. Transect #3 on Plow Island has not been relocated since 1994, so the monitoring has
focused on six transects rather than seven. Although the monitoring was designed for data analysis within
macroplots rather than by transect, the number of plants per transect has dropped to such low levels that data
were analyzed by transect for this study.
Monitoring plots were surveyed on October 8, 2002. Another visit was made on November 1 to see if any of
the plants had produced flowers or fruit between October 8 and November 1.
VISUAL SURVEYS
Some visual survey work took place on October 8, 2002, in the vicinity of the BLM monitoring plots. An
attempt at a visual survey was made on October 9, but water levels were too high. A visual survey by boat of
populations at the lower end of the Hanford Reach was made on November 1, 2002.

4. CURRENT STATUS OF COLUMBIA YELLOWCRESS (RORIPPA COLUMBIAE) ON THE HANFORD REACH
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
49
Fig. 4.1. Range of Rorippa columbiae on the Hanford Reach.

4. CURRENT STATUS OF COLUMBIA YELLOWCRESS (RORIPPA COLUMBIAE) ON THE HANFORD REACH
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
50

4. CURRENT STATUS OF COLUMBIA YELLOWCRESS (RORIPPA COLUMBIAE) ON THE HANFORD REACH
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
51
Fig. 4.2. Location of BLM monitoring transects established in 1991 for Rorippa columbiae.

4. CURRENT STATUS OF COLUMBIA YELLOWCRESS (RORIPPA COLUMBIAE) ON THE HANFORD REACH
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
52

4. CURRENT STATUS OF COLUMBIA YELLOWCRESS (RORIPPA COLUMBIAE) ON THE HANFORD REACH
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
53
Results
There was a precipitous decline in the number of stems per transect between 1995 and 1998, and there has
been little recovery between 1998 and 2002 (Fig. 4.3; Table 4.1).
The presence of flowers and fruits (Table 4.2) also decreased precipitously between 1995 and 1998. These
data combined with the visual observations of the Hanford Reach population in 2002 suggest that virtually no
sexual reproduction took place in the Hanford Reach population in 1998 or 2002.
The visual survey included islands and shoreline from Homestead Island upstream to just below the White
Bluffs boat launch. Plants were found in four areas: within two BLM monitoring transects, on Homestead
Island outside of a monitoring transect, and on an island just below the White Bluffs boat launch. A total of
seven patches totaling 110 stems were found on the island south of the White Bluffs boat launch. None of the
stems had either flowers or fruit. No other areas supported plants; at least some of these areas supported plants
as recently as 1995.
0
200
400
600
800
1000
1200
1400
1600
1800
Homestead Island 1
Homestead Island 2
Homestead Island 3
North Forked Island
Plow Island 1
Plow Island 2
Number o
f
Stems
1994
1995
1998
2002
Fig. 4.3. Stem counts of Columbia yellowcress (Rorippa columbiae) in study plots on the Hanford Reach,
1994–2002. Stem counts in 1998 and 2002 ranged only between 0–3 and 0–10 respectively.

4. CURRENT STATUS OF COLUMBIA YELLOWCRESS (RORIPPA COLUMBIAE) ON THE HANFORD REACH
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
54
Table 4.1. Number of stems observed per transect, Hanford Reach population of Columbia yellowcress
(Rorippa columbiae), 1994–2002.
Transect 1994 1995 1998 2002
Homestead Island 1 953 845 3 0
Homestead Island 2 64 59 0 0
Homestead Island 3 159 201 0 0
North Forked Island 967 1546 3 10
Plow Island 1 878 1082 3 4
Plow Island 2 425 621 1 0
Table 4.2. Average numbers of flowers and fruit per plant, Hanford Reach population of Columbia
yellowcress (Rorippa columbiae), 1994–2002.
1994 1995 1998 2002
Transect Flowers Fruit Flowers Fruit Flowers Fruit Flowers Fruit
Homestead Island 1 0.6 2.1 0.4 0.1 0 0 0 0
Homestead Island 2 0Fruits
present
0 0 0 0 0 0
Homestead Island 3 Flowers
present
Fruits
present
Flowers
present
Fruits
present
0 0 0 0
North Forked Island 0.8 1.1 0.1 0.1 0 0 0 0
Plow Island 1 0.4 0000000
Plow Island 2 1.9 1.8 0 0 0 0 0 0
Discussion
In 1982 and in 1994, the Hanford Reach supported millions of stems of Columbia yellowcress in numerous
clumps along a 50-mile stretch of river (Sauer and Leder 1985, P. Camp pers.obs.). Since 1997, there has
been a precipitous decline in the number of observed stems and patches of stems on the Hanford Reach. In
2002, less than 200 stems were seen in the area from the White Bluffs boat launch to the Ringold Boat
Launch, an area which once supported at least 36,000 stems (Camp 1992). In 2002, there were no observed
flowers or fruits on any stems.
It seems likely that some hydrologic change may be implicated in the current decline. Simmons (2000)
conducted an experimental manipulation of an artificial population of Rorippa columbiae and found that
continuously submerged plants exhibited leaf chlorosis, weak stems, and negative growth. Monitoring of
several populations has shown that hydrologic changes influence population levels of Columbia yellow cress
(Kaye 1996). Gehring (1994) hypothesized that sexual reproduction may depend on “long days,” and so
plants exposed too late in the season to experience long photoperiods may not flower.
Gehring’s work from 1991 through 1993 on the Hanford Reach took place through the month of September
(Gehring 1994). Sauer and Leder (1985) also commented that in 1982 the areas where the plants grew were

4. CURRENT STATUS OF COLUMBIA YELLOWCRESS (RORIPPA COLUMBIAE) ON THE HANFORD REACH
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
55
more or less continuously exposed after late August. Observation on the Hanford Reach since 1997 suggests
that plants are not regularly exposed until October, and during the period of maximum growth for plants (late
summer and early fall), the elevation at which the plants grow on the Hanford Reach is submerged for most of
the daylight hours. Plants are submerged during daylight hours on the lower Hanford Reach even after
Reverse Load Factoring begins in mid-October, due to the 6–8 hour lag time from Priest Rapids Dam to the
lower Hanford Reach. Reverse Load Factoring is a river management strategy designed to keep river levels
low over Vernita Bar to allow for redd counting, and it begins in mid-October and continues until mid-
November. However, at least one subpopulation of R. columbiae close to Vernita Bar also appears to be
extirpated. Hydrologic changes include Reverse Load Factoring (which began in 1988), summer spill for non-
listed fish species (July 1–August 15), and/or higher river levels for power production prior to Reverse Load
Factoring. There have also been lower spring peaks since 1995 (T. Dresser pers. comm.). Further work should
be done to characterize the hydrologic changes on the Hanford Reach since 1982 and their possible impacts
on R. columbiae. The USFWS has requested this work from Grant County PUD.
The lack of spring scouring floods and the subsequent development of woody vegetation in the riparian zone
has been implicated in the decline of Columbia yellowcress at Pierce Island on the lower Columbia (Habegger
et al. 2000) but seems unlikely as a major causative factor in the current decline of the Hanford Reach
population. The combination of very high population levels during portions of the last 20 years and the
presence of large areas of suitable non-vegetated habitat upslope from the existing clusters of plants suggests
that the current decline is probably attributable to more recent hydrologic changes. Siltation, also implicated
at Pierce Island (Habegger et al. 2000), may be another factor in the decline of R. columbiae on the Hanford
Reach.
It is difficult to evaluate the significance of the current decline. Monitoring records for the Hanford Reach
population reach back to 1982 (Table 4.3). There was a strong decline in the late 1980s and then high
population levels from 1990 to 1994. The current, very low population levels were first seen in 1997 and have
been low in every year since 1997. No hourly analysis of the flow rate at Priest Rapids dam has been done to
see if there are correlations between river regulation and the decline of the Hanford population.
Table 4.3. General trends in Columbia yellowcress (Rorippa columbiae) population on the Hanford Reach,
1982–2002. BLM = Bureau of Land Management; PNNL = Pacific Northwest National Laboratory;
TNC = The Nature Conservancy; WNHP = Washington Natural Heritage Program.
Year Population Information Agency
1982 high survey PNNL
1988 low monitoring BLM
1989 low monitoring BLM
1991 high monitoring BLM
1992 high monitoring BLM
1993 high monitoring BLM
1994 high survey, monitoring BLM, PNNL, TNC
1996 high monitoring PNNL
1997 none monitoring PNNL
1998 low monitoring PNNL
1999 low monitoring, survey PNNL
2000 low monitoring PNNL
2002 low monitoring, survey BLM, WNHP

4. CURRENT STATUS OF COLUMBIA YELLOWCRESS (RORIPPA COLUMBIAE) ON THE HANFORD REACH
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
56
Recommendations
• Gather information on the status of the species throughout its range. (WNHP)
• Using established monitoring protocols, continue annual monitoring of BLM sites for at least the next
three years and conduct further surveys along the Hanford Reach to evaluate the population as a
whole (BLM, Hanford Reach National Monument).
• Perform an analysis of river flows on an hourly basis and patterns of decline of the species (Grant
County PUD).
• Re-evaluate the known information in 2-3 years and consider further action if decline continues.
Further action could include hydrologic manipulation, establishment of new subpopulations, or
control of riparian vegetation (all parties).

BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
57
5. Current Status of Umtanum Desert Buckwheat (Eriogonum
codium) on the Hanford Site
Florence E. Caplow
Introduction
Umtanum desert buckwheat, Eriogonum codium, is a small, mat-forming shrub in the buckwheat family
(Polygonaceae). The species, which forms low mats up to 1 m in diameter, is an extremely narrow endemic
and has no close relatives in Washington. The only known population is comprised of approximately 5000
plants spread over a 2 km long, 0.79 ha section of Umtanum Ridge in Benton County (Dunwiddie et al.
2000a). The site lies entirely within the McGee Ranch–Riverlands Unit of the Hanford Reach National
Monument. Eriogonum codium Reveal, Caplow & Beck was first described in 1996 (Reveal et al 1996). It is
a Candidate species for listing with the U.S. Fish and Wildlife Service and is listed as Endangered in
Washington.
Eriogonum codium has been the subject of an intensive demographic monitoring project since 1997. Initial
findings indicate that E. codium is a long-lived species (greater than 100 years) with high flower production,
low germination rates, high seedling mortality, and high variability of growth between individuals and
between years. Between 1997 and 1999 annual adult mortality exceeded recruitment, ranging from 0% to 4%.
One hundred and sixty-nine new seedlings were observed during the same period, and none survived more
than one year. Most seedlings died between May and July (Dunwiddie et al. 2000a).
This report summarizes the results of monitoring during the period 2000-2002, with further discussion of the
trends over the six years since monitoring began.
Methods
In 1997, a series of 24 permanent 1 m x 2 m plots were randomly placed along three 50 m belt transects
within the largest subpopulation of Eriogonum codium. Individual adult plants were mapped and tagged.
More than 100 adult plants have been followed annually since 1997. For each tagged adult, data was collected
on length and width of plants, number of inflorescences, and percent of canopy dead within each adult.
Seedlings also were mapped within the 1 m x 2 m plots in May and in July of each year. Number of leaves
and distance to nearest adult were recorded for each seedling (Dunwiddie et al. 2000a). The May seedling
search was omitted in 1998 and 2002.
Results
ANNUAL MORTALITY AND RECRUITMENT
One adult plant died between 1999 and 2000, four adult plants died between 2000 and 2001, and one adult
plant died between 2001 and 2002 (Table 5.1). This pattern is consistent with what we have seen since 1998.
The average annual mortality rate between 1998 and 2002 is 2.0 %. 1999 and 2001 were high mortality years,
while 1998, 2000, and 2002 were low mortality years.

5. CURRENT STATUS OF UMTANUM DESERT BUCKWHEAT (ERIOGONUM CODIUM) ON THE HANFORD SITE
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
58
Table 5.1. Annual mortality and recruitment of Umtanum desert buckwheat (Eriogonum codium) on the
Hanford Site.
Year
Mortality
(# of Plants) Mortality Rate
Recruitment
(# of Plants)
1998 0 0 1
1999 4 0.04 0
2000 1 0.01 0
2001 4 0.04 0
2002 1 0.01 0
TOTAL 10 1
Annual Avg. 20.02 0.2
Recruitment has continued to be very low. Only one recruitment event has been observed since monitoring
began in 1997. A single plant that was first observed in 1999 and believed to be a 1998 seedling was still alive
in 2002. It is now 24 cm2 in area but has not yet flowered. Another plant suspected to be from the 1995 cohort
has also not yet flowered.
INFLORESCENCE PRODUCTION
Inflorescence production varies widely between years and between plants (Fig. 5.1).
Average production has varied from a high of 27.1 inflorescences per plant (range 0–209) in 1997 to a low of
5.4 inflorescences per plant (range 0–61) in 1999. 1999 and 2001 were years of low production. These were
the same years that had the highest mortality (Table 5.1).
A small number of plants (7) produced more than 100 inflorescences in 2002, while more than half of the
plants produced less than 10 inflorescences in 2002. This pattern has also been seen in other years. In other
words, a small number of plants are producing a disproportionate percentage of the inflorescences.
SEEDLING PRODUCTION
Seedling production varies between years (Fig. 5.2). The highest year for seedling production was 2000 (72
seedlings). The lowest year for seedling production was 2002, when no seedlings were produced. Seedling
production also varies widely between quadrats: Three of the 24 permanent quadrats have produced 45% of
the total number of seedlings counted since the study began (Fig. 5.3). Three quadrats have produced no
seedlings at all. Only one quadrat has produced seedlings in every year, and only eight quadrats have
produced seedlings in at least half the years. Seedling mortality has been 100% from one year to the next,
with the exception of 1998. The 1998 seedling that survived was not found during the July survey and is
believed to have germinated later in the season. Seed viability studies conducted by Ransom Seed Laboratory
in 2002 found that 5% of the seed was not dormant and germinated in 21 days with moisture and light. This
suggests that a fraction of the seed would not require stratification to germinate and could potentially
germinate during summer or fall. This is further suggested by the 1999 data, in which more seedlings were
found in July than in May. The weather from May through July in 1999 was unusually cool and dry (Hanford
Meteorological Station web site, February 6, 2003).

5. CURRENT STATUS OF UMTANUM DESERT BUCKWHEAT (ERIOGONUM CODIUM) ON THE HANFORD SITE
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
59
0
5
10
15
20
25
30
35
1997 1998 1999 2000 2001 2002
Number of
Infloresences
Fig. 5.1. Average number of infloresences of Umtanum desert buckwheat (Eriogonum codium) per plant,
1997–2002. Vertical bars indicate ± one standard error.
0
10
20
30
40
50
60
70
80
1997 1998 1999 2000 2001 2002
Number of
Seedlings
livin g
dead
Fig. 5.2 Annual seedling production of Umtanum desert buckwheat (Eriogonum codium), 1997–2002. Results
are from July surveys.
11403
8%
13006
16%
23408
21%
Other (n =21)
55%
Fig. 5.3. Proportion of total seedlings of Umtanum desert buckwheat (Eriogonum codium) produced by the
three most productive quadrats, 1997–2002.

5. CURRENT STATUS OF UMTANUM DESERT BUCKWHEAT (ERIOGONUM CODIUM) ON THE HANFORD SITE
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
60
Mortality between May and July has varied from 70% to 92% (Table 5.2). In general, we have been
successful at relocating May seedlings during the July survey, whether alive or dead at the time of the survey.
This suggests that most of the year’s seedlings were found in the 1998 and 2002 July surveys.
Discussion
The years of 1999 and 2001 were both years of relatively low flower production and high mortality of adult
plants. 1999 was also a year of low seedling production. Due to the correlation between annual mortality and
annual inflorescence production, meteorological patterns between 1997 and 2002 were investigated, with
particular attention to 1998–1999 and 2000–2001 (HMS 2003). In general, there were no extreme patterns,
with the exception of March and April of 1999 (unusually dry) and November and December of 2000
(unusually cold). The dry conditions of 1999 might explain the low seedling production, but March and April
of 2001 (another year of high mortality and low flower production) were quite wet. There were also no
unusual cold periods in the winter of 1998–1999 or 2000–2001. In fact, most winters since 1997 have been
slightly above average in temperature. However, low seedling production in 2002 could be correlated with dry
conditions: All months from March through July exhibited below-average precipitation, with the exception of
June. At this point, there is only a weak potential relationship between meteorological conditions and plant
performance or mortality.
Because monitoring efforts have spanned such a short period of time, it is not clear if observations indicate a
true decline of the population E. codium or a situation of extremely episodic recruitment. Most years since the
monitoring began have been years of average precipitation. 1999 was an unusually dry year (50% of normal
precipitation), and 2000 was a somewhat wet year (116% of normal precipitation). 1995 and 1996 were the
wettest years since records began in 1946 (200% average precipitation), so one would expect those years, if
any, to be years of recruitment. We have one suspected 1995 cohort plant in the study, but when monitoring
began in 1997 we saw very few small plants (Dunwiddie et al. 2000a).
We continue to be concerned about the low recruitment in the population. Further studies on the seed bank
and competition with cheatgrass are planned for in 2003.
Recommendations
It is recommended that annual monitoring be continued for at least the next four years. Within a ten-year
period there may be at least one episode of significant recruitment; by skipping one or more years, we may
miss the year in which that recruitment occurs.
Effects of monitoring on the population could be minimized by eliminating the May seedling count. It is also
desirable to check portions of the populations that are not within the monitoring area to determine whether
recruitment patterns are low outside the monitoring area as within, and are not the result of the monitoring
itself.
Methods for evaluating cheatgrass cover and its impact within the study plots should also be developed.
Currently the Umtanum Ridge portion of the McGee Ranch–Riverlands Unit of the Hanford Reach National
Monument is closed to public access. Because of the extremely limited distribution of Eriogonum codium, the
species’ lack of fire tolerance, and the potentially disruptive effects of off-road vehicle use and other
recreational impacts, it is recommended that current management policies regarding public access to this area
be continued in order to protect this extremely rare species.

5. CURRENT STATUS OF UMTANUM DESERT BUCKWHEAT (ERIOGONUM CODIUM) ON THE HANFORD SITE
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
61
Umtanum desert buckwheat is completely intolerant of wildfire (Dunwiddie et al. 2000a). A wildfire burning
through Umtanum desert buckwheat’s habitat would have a devastating effect upon the only known
population of this extremely rare species. In order to help perpetuate this sensitive species, methods aimed at
protecting the population from wildfires as well as from impacts associated with fire suppression activities
must be incorporated into a comprehensive fire management plan for the Umtanum Ridge portion of the
Hanford Reach National Monument.
Table 5.2. Total seedling production of Umtanum desert buckwheat (Eriogonum codium) on the Hanford Site,
1997–2002.
Year Month Living Dead Total
1997 June 41 0 41
1997 July 6 29 35
1998 July 5 8 43
1999 May 0 1 1
1999 July 18 6 24
2000 May 54 18 72
2000 July 16 56 72
2001 May 36 1 37
2001 July 3 45 48
2002 July 0 0 0

5. CURRENT STATUS OF UMTANUM DESERT BUCKWHEAT (ERIOGONUM CODIUM) ON THE HANFORD SITE
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
62

BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
63
6. Current Status of White Bluffs Bladderpod (Lesquerella
tuplashensis) on the Hanford Site
Florence E. Caplow
Introduction
White Bluffs bladderpod, Lesquerella tuplashensis, is a low-growing, taprooted perennial herb in the mustard
family (Brassicaceae). Discovered only in 1994, L. tuplashensis is a narrow endemic, restricted to a 17 km
stretch of the White Bluffs of the Columbia River in Franklin County (Rollins et al. 1995, WNHP 2000). The
population lies entirely within the Wahluke Unit of the Hanford Reach National Monument. The species
inhabits dry, steep exposures of the White Bluffs where a layer of alkaline calcium carbonate (caliche) soil
has been exposed. Overall vegetation cover is low in this stressful environment. Common associates include
Wyoming big Sagebrush, Sandberg’s bluegrass, and cheatgrass. L. tuplashensis is a Candidate species for
listing by the U.S. Fish and Wildlife Service under the Endangered Species Act and is listed as Threatened in
Washington (Washington Natural Heritage Program 1997).
Lesquerella tuplashensis is a short-lived perennial most closely related to Lesquerella douglasii, which grows
on cobble bars on the Columbia River. Demographic studies of L. tuplashensis were begun in 1997. The
studies had two components: life history plots placed non-randomly throughout the population, and counts of
reproductive individuals in 100 m transects placed randomly throughout the northern half of the population.
In 2002, only the transects were surveyed, and only this portion of the study is summarized below. Results
from life history plots, 1997 to 1999, are presented in Dunwiddie et al. (2000b).
Methods
Sampling was conducted in the northern one-third of the L. tuplashensis population. This area contains the
most contiguous and least disturbed portion of the population: There are no evident impacts from nearby
agricultural activities, and this portion of the population is generally <1 km from a vehicle track. In 1997, ten
permanent 100 m transects were installed at random locations within a 3.7 km length of this area. An
additional ten transects were added in 1998. All flowering plants were counted along each transect, and
recorded according to their location: Plants growing on the top of the bluff are recorded as “Top” plants,
plants growing in the cross-section of the caliche layer exposed at the top of the bluffs are recorded as
“caliche” plants, and plants growing below the caliche on the upper slope are recorded as “slope” plants.
Plants were censused in mid-May to early June in 1997, 1998, 1999, and 2002.
Results
The numbers of adult L. tuplashensis varied greatly between years. Our counts increased 21% on the transects
between 1997–98, decreased by 65% between 1998–99, and decreased by 58% between 1999–2002 (Fig.
6.1). The total of 3,212 plants over ten transects in 2002 is the lowest since the study began, but that figure is
within the possible surveyor error of the 1997 count of 3,793.
Results from the life-history plots showed that nearly all adult plants flower every year (Caplow and
Dunwiddie 2000). Therefore, counts of flowering plants likely represent most of the adults in the sample

6. CURRENT STATUS OF WHITE BLUFFS BLADDERPOD (LESQUERELLA TUPLASHENSIS) ON THE HANFORD SITE
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
64
population. Projecting the transect data to the 3.7 km portion of the population from which these samples are
derived, one may conclude that the number of adult plants within the 3.7 km area varied between a low of
approximately 12,000 plants in 2002 to a high of approximately 32,000 plants in 1998 (Fig. 6.2). Therefore, it
is reasonable to conclude that the White Bluffs population is probably well in excess of 50,000 plants in
“good” years. More monitoring is needed to determine the magnitude and frequency of high- and low-number
years, as well as to obtain an understanding of the causes of these annual fluctuations.
3793
8382
5501
3212
0
2000
4000
6000
8000
10000
1997 1998 1999 2002
Year
Number o
f
Plants in
Flower
Fig. 6.1. Total number of flowering plants of White Bluffs bladderpod (Lesquerella tuplashensis; 10
transects), 1997–2002.
12038
21699
32603
14034
0
5000
10000
15000
20000
25000
30000
35000
40000
1997 1998 1999 2002
Number o
f
Plants in
Flower
Fig. 6.2. Estimated number of flowering plants of White Bluffs bladderpod (Lesquerella tuplashensis) in the
sample area. Sample area is a 3.7 km length of the northern one-third of the entire population. Vertical bars
indicate 95% confidence intervals. Estimated values are based on 20 transect samples except for 1997, which
is based on 10 transect samples.

6. CURRENT STATUS OF WHITE BLUFFS BLADDERPOD (LESQUERELLA TUPLASHENSIS) ON THE HANFORD SITE
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
65
Lesquerella tuplashensis is not uniformly distributed in the study area. Counts of plants along the 100 m
transects varied considerably. However, plants along most of the transects appear to respond similarly to
annual conditions (Fig. 6.3).
There are also changes in the spatial distribution of plants along the slope (Fig. 6.4). For instance, between
1997 and 1999 the proportion of plants found on the slope itself vs. in the caliche or on top of the caliche
decreased from nearly 20% to less than 5%. Conversely, the proportion of plants on the flat top of the caliche
layer increased from slightly more than 30% to nearly 60% between 1997 and 1999.
Discussion
Data from the permanent transects provide some indication of the magnitude and direction of trends in the
overall population of Lesquerella tuplashensis from 1997–2002 (Figs. 6.1, 6.2). Since these transects were
randomly selected only within the northern portion of the site, they may not necessarily represent changes in
the overall population. However, they should be representative of changes that occur in the northern portion
of the population.
The long-term trend and significance of changing proportions over slope position is not known. Given the
relatively short life span of individual plants (4–5 years, based on life history plots; Dunwiddie et al.2000b),
there may be cyclical colonization of and extirpation from various portions of the slope.
The population of L. tuplashensis is threatened by a number of factors within the Hanford Reach National
Monument and beyond its borders. Slope failure along the White Bluffs, attributable to irrigation agriculture
in neighboring lands, has the potential to create local disturbances within a portion of the population.
Recreational impacts such as trampling and illegal off-road vehicle use increase erosion locally. Invasive
plant species, especially yellow starthistle (Centaurea solstitialis), may compete with L. tuplashensis for
limited moisture and contribute to increases in wildfire frequency (WNHP 2000, Soll et al. 1999).
A critical methodological question is the number of transects and the frequency of monitoring needed to
detect a significant change in the population of L. tuplashensis, particularly when natural fluctuations in the
population can be 100% or more from year to year. One approach is to assume that the years from 1997 to
2002 represent a normal range of variation: i.e., the northern portion of the population can range from 12,000
+/- 1450 plants to 33,000 +/- 3100 plants without affecting the viability of the population. The lower end of
the confidence interval of the lowest population estimate is 10,550, so a conservative threshold for concern
could be 10,500 plants. Data indicate that the population can fluctuate widely from year to year, so just one
year of a population below 10,500 may not be cause for concern. Multiple years of low population levels are
likely to be of greater significance.
Recommendations
SAMPLING PROTOCOLS
A reasonable management objective for Lesquerella tuplashensis would be to maintain at least 10,500
reproductive plants of L. tuplashensis in the northern 3.7 km of the White Bluffs population from 2003–2013.
If the population remains below this threshold for two years or more, management should conduct further
research into the causes of decline and/or initiate management action(s). Under this scenario, a sampling
objective could then be 90% confidence that the population estimates are within 25% of the estimated true
value.

6. CURRENT STATUS OF WHITE BLUFFS BLADDERPOD (LESQUERELLA TUPLASHENSIS) ON THE HANFORD SITE
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
66
0
200
400
600
800
1000
1200
1400
1600
1800
2000
1997 1998 1999 2002
Number of Flowering Plants
Transect 2
Transect 3
Transect 6
Transect 12
Transect 13
Transect 15
Transect 16
Transect 18
Transect 28
Transect 36
Fig. 6.3 Total number of flowering plants of White Bluffs bladderpod (Lesquerella tuplashensis) per transect
(10 transects), 1997–2002.
0%
20%
40%
60%
80%
100%
1997 1998 1999 2002
Proportion o
f
Population
Top
Caliche
Slope
Fig. 6.4 Relative spatial distribution of flowering plants of White Bluffs bladderpod (Lesquerella
tuplashensis; 10 transects), 1997–2002.

6. CURRENT STATUS OF WHITE BLUFFS BLADDERPOD (LESQUERELLA TUPLASHENSIS) ON THE HANFORD SITE
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
67
A full monitoring of once every three to five years is recommended for the current degree of threat for this
population. However, if the population estimate (including its confidence interval) is at or below the threshold
of 10,500 plants, the population should be sampled again in the following year. In years where full monitoring
is not taking place, a visual survey of the northern end of the population should take place. Monitoring and
visual surveys should also assess the extent of invasive plant species within the population area.
There is a clear decrease in the range of confidence intervals when 20 transects are sampled, suggesting that
all 20 transects must be sampled in order to be within 25% of the estimated true population value. When
confidence intervals were calculated on the basis of 20 transect samples between 1998 and 2002, confidence
intervals were nearly always within the target range; when calculations were based on only 10 transects,
estimates were rarely within this range (Table 6.1).
INVASIVE SPECIES
Invasive plant species pose a threat to at least portions of the White Bluffs bladderpod population. Invasive
species may compete with White Bluffs bladderpod for moisture, nutrients, or other limiting resources, and
may alter fire regimes or other ecosystem properties upon which Lesquerella tuplashensis depends. Invasive
species within the range of L. tuplashensis should be mapped and appropriate treatments applied to minimize
these species’ effects on the bladderpod population. An infestation of yellow starthistle (Centaurea
solstitialis) was discovered during 2003 within a portion of White Bluffs bladderpod’s range (Evans et al.
2003). The infestation was mapped and plants were removed manually. Timely followup treatment and
monitoring of this infestation is necessary to protect the narrow habitat of L. tuplashensis.
Table 6.1. Comparison of confidence intervals for White Bluffs bladderpod (Lesquerella tuplashensis),
sampling 10 or 20 transects.
a. 95% confidence
Twenty Transects Ten Transects
Year
Estimated
Total
Individuals
Confidence
Interval
Proportion of
Mean
Estimated
Total
Individuals
Confidence
Interval
Proportion of
Mean
1997 14034 5491 0.39
1998 32603 6287 0.19 31013 10394 0.34
1999 21699 6589 0.30 20354 12025 0.59
2002 12038 2893 0.24 11884 4904 0.41
b. 90% confidence
Twenty Transects Ten Transects
Year
Estimated
Total
Individuals
Confidence
Interval
Proportion of
Mean
Estimated
Total
Individuals
Confidence
Interval
Proportion of
Mean
1997 14034 4608 0.33
1998 32603 5276 0.16 48211 8723 0.28
1999 21699 5530 0.25 34854 10091 0.50
2002 12038 2428 0.20 20609 4116 0.35

6. CURRENT STATUS OF WHITE BLUFFS BLADDERPOD (LESQUERELLA TUPLASHENSIS) ON THE HANFORD SITE
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
68

BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
69
7. Survey for Northern Wormwood (Artemisia campestris
subsp. borealis var. wormskioldii) and Potential Habitat on the
Islands of the Hanford Reach
Florence E. Caplow
Northern wormwood, Artemisia campestris ssp. borealis var. wormskioldii, is a low, taprooted biennial or
perennial forb in the composite family (Asteraceae). Northern wormwood is a regional endemic within the
Columbia Basin, known only from riparian areas of the Columbia River at two locations: Miller Island at the
eastern end of the Columbia Gorge in Klickitat County, and the Beverly site in Grant County. Northern
wormwood is a Candidate species for listing under the Endangered Species Act with the USFWS and is
considered Endangered in Washington (WNHP 1997).
The islands of the Hanford Reach were surveyed for existing or potential habitat of northern wormwood on
April 22–23, 2003. While no existing populations of this rare taxon were found, a number of islands exhibited
habitats that were highly similar to that of the Beverly site. The Beverly site, upstream of the Hanford Reach,
currently supports the largest known population of Artemisia campestris subsp. borealis var. wormskioldii.
This site has the following characteristics (Framatome AMP DE&S 2003):
• Stabilized cobble or sand substrate.
• Elevation of most of the population between 1 ft. and 6 ft. of the elevation of the high-water line.
• Most of the population on gravel islands or peninsulas surrounded on two or more sides by water.
• Low total vegetation cover.
• High cover of bare ground.
• Low noxious weed cover.
• Most common associated native species: Eriogonum compositum, Artemisia campestris var.
scouleriana, Lesquerella douglasii, Descurainia pinnata, Lomatium grayii, Draba verna.
The areas on the islands which most resembled the Beverly site in terms of substrate, vegetation, and
elevation above high water were mapped as potential reintroduction sites (Table 7.1). Each polygon was
identified as being either “moderate” or “excellent” habitat, based on the presence or absence of weedy
species and the similarity of the site to the Beverly population area. Areas on the islands of the reach that are
not within these polygons are less likely to be appropriate habitat for the species. Further detailed work is
necessary before choosing a particular site as a reintroduction area.
Potential habitat for northern wormwood on the Columbia River shoreline was not assessed. Potentially
suitable habitat could be identified using existing vegetation maps (Easterly and Salstrom 2001). Shoreline
habitat is considered a lower priority as a reintroduction area, however, due to its greater vulnerability to
disturbance. Both extant populations occur on islands, so there may be aspects of island hydrology that are
particularly important for the species.

7. SURVEY FOR NORTHERN WORMWOOD (ARTEMISIA CAMPESTRIS SUBSP. BOREALIS VAR. WORMSKIOLDII) AND POTENTIAL HABIT AT
ON THE ISLANDS OF THE HANFORD REACH
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
70
Table 7.1. Potential habitat for northern wormwood (Artemisia campestris subsp. borealis var. wormskioldii)
on islands in the Hanford Reach. Island names are from USGS 71/2′ maps. Island numbers are from Hansen
and Eberhardt (1971).
Island Area Habitat Quality
Locke Island West side Moderate
Rosseau Island Most of island Moderate
East of 100F East side Excellent
Plow Island (Island 12) North end Moderate
Plow Island (Island 12) Center Moderate
Homestead Island Southeast side Moderate
Island 15 West side Moderate
Wooded Island North end Moderate
Johnson Island North end Excellent
Island 18 North end Excellent
Island 19 Most of island Excellent

Invertebrates

BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
73
8. Aquatic Macroinvertebrates
Robert L. Newell
Introduction
This chapter reviews the literature of aquatic macroinvertebrates of the Hanford Site and compares taxonomic
findings of studies conducted between 1948 and 2002. The results of recent benthic (bottom dwelling) and
light-trap sampling are presented in relation to the distribution of Trichoptera (caddisflies) in Hanford aquatic
environments and to the effects of wildfire on macroinvertebrates in two spring streams. Surveys of the
Hanford Reach of the Columbia River for Pacific crayfish (Pacifasticus leniusculus towbridgii) and the
western pearl mussel (Margaritinopsis falcate) are described. Newell (2003) provides details not included
here.
Purpose and Scope
The primary objective of this study was to survey and compile all known records of aquatic
macroinvertebrates of the Hanford Reach National Monument, including records from the Hanford Reach of
the Columbia River, its local tributaries, and three spring streams on the Fitzner-Eberhardt Arid Lands
Ecology (ALE) Reserve, in order to prepare a comprehensive literature review and to document changes in
the taxa of aquatic macroinvertebrates in these environments over time. In 2002, this study also conducted
benthic (bottom dwelling) sampling of Rattlesnake Spring and Snively Spring on the ALE Reserve. These
collections were compared to those from light-trap sampling that recently had been conducted near the two
springs, in the sand dunes area between the springs and the Columbia River, and on the Hanford Reach in
order to evaluate the origin of several species of adult Trichoptera that had been captured in the light traps
near the springs. The benthic sampling was also compared to similar sampling that had been conducted during
spring 2000 in order to evaluate the effects on aquatic macroinvertebrates of the major wildfire that occurred
in July 2000. Additionally, this study examined the current status of the crayfish, Pacifasticus leniusculus
towbridgii, and the western pearl mussel, Margaritinopsis falcata, in the Hanford Reach.
Methods
THE HANFORD REACH OF THE COLUMBIA RIVER
The Hanford Reach is the only free-flowing, non-tidal segment of the Columbia River within the United
States. The Hanford Reach study area has previously been described in Newell (1998) and elsewhere. The
Reach is home to a diverse assemblage of fish and other aquatic organisms, is a major spawning site for
Chinook salmon, and provides valuable nesting and feeding habitat for migratory waterfowl such as ducks,
geese, and pelicans. The width of the river varies from approximately 1000 ft. to 3300 ft. (305–1005 m)
within the Hanford Reach (PNNL 1998). Flows through the Reach fluctuate significantly on a daily basis as
well as seasonally and annually and are controlled by releases from Priest Rapids Dam. During the last ten
years, flows have averaged 120,000 cfs (340 m3/sec). But in 1996–97 peak flows reached 415,000 cfs (1175
m3/sec), far from the most recent flood of 1948 when peak discharge reached 742,000 cfs (2101 m3/sec)

8. AQUATIC MACROINVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
74
(PNNL 1998). Large annual and diurnal flow variations can cause water level fluctuations of about 25 ft. (7.6
m) that can be devastating to aquatic invertebrates. Even during the summer and fall, daily water levels may
fluctuate by nearly 5 vertical feet (1.5 m) as hydroelectric generating needs dictate (pers. obs.).
Crayfish (Pacifasticus leniusculus towbridgii) and western pearl mussel (Margaritinopsis falcata) sampling
occurred on the Hanford Reach during late winter (February–March 2002) and late spring (May 2002).
Shorelines were walked, looking for mussel shells, and live mussels and rocks were randomly turned to
search for crayfish. Crayfish traps were baited with fish and left overnight. Sampling areas were in the
vicinity of the old Hanford townsite and one mile upstream from the Hanford 300 area. Several miles of
shoreline were examined in both locations. The Washington Department of Fish and Wildlife was contacted
for data on their recent snorkeling surveys. Current and historical records for M. falcata were reviewed and
tabulated.
SPRING STREAMS OF THE ARID LANDS ECOLOGY RESERVE
Sampling was conducted in Snively Spring and Rattlesnake Spring to assess effects of the recent fire that
burned areas around the spring streams. The study area, including a third spring, Benson Spring, has been
described in Newell (1998), Pickel (2000), Newell et al. (2001), and elsewhere. Benson Spring is located in
Bobcat Canyon and comprises three small springs that seep out of the base of the foothills near the north end
of Rattlesnake Mountain. The discharge for this spring is approximately 0.0023 cubic meters/second, and it
flows approximately 800–900 m before disappearing into the ground. Snively Spring originates from ground
seeps about 5 km south of Rattlesnake Spring. Its perennial flow is approximately 3.6 km. Rattlesnake Spring
originates from ground seeps, and its perennial flow is approximately 2.5 km before it disappears into the
ground. This stream is the largest of the three and average discharge is approximately 0.01 cubic
meters/second. Prior to the recent wildfire, Rattlesnake Spring had a luxuriant riparian zone that was heavily
used by many animals, including the large elk herd present on the Monument, especially during the hot
summers.
Each of the spring sampling stations was visited during the winter of 2002. Four stations in Rattlesnake
Spring and four stations in Snively Spring were sampled. Stations were approximately equidistant from one
another along the entire flowing water stretch of each spring stream. Samples were taken with a D-ring
aquatic net with a 500-micron mesh. The sampler waded into the stream and placed the net downstream. The
substrate was disturbed by kicking, wiping, and brushing the rocks and substratum. The current then carried
the thus dislodged organisms into the net. Typically, up to 6 linear feet (2 m) of bottom was disturbed at each
sample point. The net contents were placed into an enamel pan. All large pieces of detritus were carefully
cleaned of organisms and discarded. The contents of the pan were poured through a very fine mesh net to
remove the excess water. All organisms were preserved with 70% ethyl alcohol, labeled, and returned to the
laboratory. Pickel (2000) used a quantitative sampler (0.093 m sq. area) of the same mesh size and similar
separation and identification techniques.
In the laboratory, the benthic samples were processed and preserved for later identification. Organisms were
identified to the lowest possible taxon, using the most current, regional, and complete references such as:
Plecoptera (stoneflies), Baumann et al. (1977) and Stewart and Stark (1993); Odonata (dragonflies and
damselflies), Paulson (1998); Trichoptera (caddisflies), Wiggins (1996); all other aquatic insects, Merritt and
Cummins (1996); and other invertebrates, Smith (2001). A reference collection of all organisms is stored at
the museum of the Washington State University/Tri-Cities campus in Richland, Washington, or at the
Entomological Museum, Washington State University in Pullman, Washington. Appendix B of this volume
acknowledges taxonomists who assisted in the identification of organisms for this study.
Night collecting trips for adult insects were conducted at both Rattlesnake Spring and Snively Spring.
Mercury vapor and ultraviolet lights were illuminated at dusk at ground level, and sampling continued until
approximately two hours after dark. Light trap sampling continued approximately twice monthly in 1998 and

8. AQUATIC MACROINVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
75
1999, from March until adults failed to appear, usually in October (Newell et al. 2001). Some adult
caddisflies were also collected from pheromone traps set to collect Lepidoptera. D. Strenge conducted
additional unpublished sampling during 2001 near the springs and in a sand dunes area located between the
springs and the Hanford Reach. This sampling provided some additional taxa and provided species names for
some genera. Casual light-trap sampling was also conducted by Newell and others along the Hanford Reach
between 1998 and 2002.
Results and Discussion
LITERATURE REVIEW
The first and possibly the most complete study of the benthic aquatic macroinvertebrates of the Hanford
Reach was by Davis and Cooper (1951). This research was conducted during 1948. No one since this study
has used a similar, intensive and comprehensive sampling approach. Davis and Cooper used a huge bottom
dredge to collect samples during 1948–1950. This study began the same year as the most recent flood on the
Columbia River (PNNL 1998). The principal objective was to survey radioactivity from the river aquatic
organisms. Any resulting radioactivity would have originated from the nuclear reactors situated on the
Columbia River along the northern boundary of the Hanford Site. The taxonomic treatment by Davis and
Cooper (1951) was extensive, given the date and state of the taxonomy of many western species of aquatic
organisms at that time. The report by Davis and Cooper (1951), like many early reports prepared at Hanford,
was classified as “Secret” for many years and was only declassified in the 1990s.
Coopey (1948, 1953) completed one of the first limnological studies of the Columbia River. He studied the
abundance of benthic organisms and provided a list of phytoplankton and zooplankton. Coopey (1953) also
studied other crustacea of the river and found an extraordinary number of crayfish, Pacifasticus leniusculus
(39 /ft2, 420 /m2).
The Pacific Northwest Laboratory, now the Pacific Northwest National Laboratory (PNNL), took charge of
research at Hanford beginning in 1965. Battelle’s researchers have published numerous papers on the fauna,
flora, and ecology of Hanford. Annual reports in the 1960s contain numerous studies on Columbia River
aquatic organisms. Coutant (1966), for example, studied phototaxis on the caddisfly, Hydropsyche cockerelli
and determined the retention time of radionuclides in mollusks and algae. Coutant et al. (1967b) also
examined upstream dispersal of some caddisflies, Hydropsyche cockerelli, Cheumatopsyche campyla, and C.
enonis. The limpet, Fisherola nutalli, was a favorite study organism (Coutant et al. 1967a, and Coutant 1968a,
b).
Becker (1972a, b) examined effects of thermal discharges on aquatic biota such as the blackfly, Simulium
vittatum, and thermal resistance of the crayfish. Wolf and Cushing (1972) published one of the earliest studies
on Rattlesnake Spring. Their work provided some productivity estimates and records of the occurrence of
periodic severe floods that had a devastating effect on the biota.
In the early 1970s, research on benthic organisms was stimulated by plans of the Washington Public Power
Supply System (WPPSS) to build nuclear power plants on the Hanford Site near the Columbia River and to
extract cooling water from the Hanford Reach (PNL 1977, 1978, 1979a, b, c; Beak Consultants Inc. 1980;
WPPSS 1977, 1984, 1985, 1986). One of these reactors operates today. These studies provide the bulk of
river aquatic invertebrate data available in the published record. Schwab et al. (1979) conducted a survey of
all springs on Hanford and provided maps, water chemistry data, elevations, and drawings. Wolf and Cushing
(1972) published one of the first studies on the ecology and environment around Rattlesnake Spring. Cushing
and Rader (1982) investigated the food of Callibaetis sp. (Ephemeroptera) nymphs from Rattlesnake Spring.
Cushing and Wolf (1982) provided an energy budget and water chemistry data. Gaines et al. (1992) and

8. AQUATIC MACROINVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
76
Gaines (1987a, b) calculated secondary production of benthic insects in Rattlesnake and Snively Springs.
Gaines et al. (1989) studied trophic relations and functional group composition of some benthic insects in
both springs. Pickel (2000) was the first to survey Benson Spring for macroinvertebrates.
COMPARISONS OF INVERTEBRATE COMMUNITIES OVER TIME
The Hanford Reach of the Columbia River
Table 8.1 lists results of 11 previous studies covering a 50-year period. These studies utilized at least three
very different sampling schemes, and this would affect sampling results. Davis and Cooper (1951) utilized a
large, barge-mounted suction dredge, and their study occurred prior to the construction of Priest Rapids Dam.
Some studies emphasized certain taxa, e.g., the WPPSS studies found many taxa of Annelida and Mollusca
and resulted in the greatest number of taxa collected (92). Some studies identified most taxa to order or genus
only, rather than to species. Differences in benthic assemblages are expected between the river suction dredge
results gathered before Priest Rapids Dam was constructed and the wading sampling conducted by Newell
(1998). Major taxa collected in all studies included Porifera, Annelida, Mollusca, Hemiptera, Ephemeroptera,
Trichoptera, Lepidoptera, Diptera, and Arachnida. Some of the species identification was made from adult
collections (Newell 1998). It is uncertain if the other studies collected adults. Major taxonomic revisions
make comparisons very difficult in the Mollusca and for other taxa. No reference collections remain for
comparison.
Tributaries of the Hanford Reach
Newell (1998) provided the first examination of Hanford Reach tributaries. The assumption that tributary
streams might contain a microcosm of the river’s fauna or that the streams might function as refugia proved
not to be true. However, some organisms were collected here and not in the nearby river in 1998, including
damselflies (Odonata—two species of Argia, Enallagma sp., and one unknown species), flatworms
(Turbellaria), and two species of riffle beetles (Elmidae).
A total of 21 taxa were collected in the tributaries in 1998 (Table 8.2) compared to 52 from the Hanford
Reach. The irrigation-return stream at Ringold had the most diverse fauna of the tributaries with 14 taxa
collected. Several major taxa found in the Hanford Reach were missing from the tributaries, including
Porifera, Bryozoa, Decapoda, Lepidoptera, and Arachnida.
Spring Streams of the Arid Lands Ecology Reserve
All aquatic macroinvertebrates collected in Rattlesnake Spring from all published studies are listed in Table
8.3. Gaines (1987a, b) collected 20 taxa, and Newell (1998) found 30 taxa, while the present study found 21
taxa. Gaines apparently did not collect or did not identify Oligochaeta, Mollusca, Amphipoda, and Hemiptera
but did identify Chironomidae to genus, while Newell (1998 and this study) identified all of these groups but
identified Chironomidae only to family. When only those groups collected and identified by both researchers
are compared, the results are: Gaines (1987a,b) 15 taxa; Newell (1998) 15 taxa; and Newell (this study) 12
taxa.
All aquatic macroinvertebrates collected in Snively Spring from all published studies are listed in Table 8.4.
Gaines (1987a, b) collected 18 taxa, while Newell (1998) found 14 taxa, and Newell (this study) collected 13
taxa. Gaines apparently did not collect or did not identify Decapoda, Amphipoda, Hemiptera, or Coleoptera
but did identify Chironomidae to genus, while Newell (1998 and this study) identified all of these groups but
identified only Chironomidae to family. Since Gaines identified Coleoptera in Rattlesnake Spring but not in
Snively Spring, there may not have been any beetles collected from Snively Spring. When only those groups
collected and identified by both researchers are compared, the total taxon count is: Gaines (1987a,b) 13 taxa;
(Text continues on page 87)

8. AQUATIC MACROINVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
77
Table 8.1. Summary of all benthic invertebrate taxa reported by the major benthic studies on the Hanford
Reach, 1948–1998, including all organisms, immatures and adults. Current taxonomic names are provided
when applicable. PHYLUM/SUBPHYLUM is in uppercase bold. CLASS/SUBCLASS is in uppercase.
Order/suborder is in lowercase bold.
Benthic Invertebrates
Davis &
Cooper
(1951)
PNL
(1976-
1979)
Beak
Consul-
tants
(1980)
WPPSS
(1977,
1984-
1986)
Newell,
(1998)
PORIFERA—Sponges
Spongilla lacustris X XXXX
COELENTERATA—Jellyfish, hydroids, corals, sea anemones
Craspedacusta sowerbii X
Hydra sp. X X X
PLATYHELMINTHES—Flatworms, tapeworms, planarians, flukes
Cura sp. X
Dugesia sp. X
Dugesia dorocephala X
Planaria sp. X
BRYOZOA—Moss animals X
Plumatella sp. X X
Pertinatella sp. X X
NEMATODA—Nematodes, roundworms, eelworms X X X
ANNELIDA—Earthworms, marine worms, leeches X X
HIRUDINEA—Leeches X X X
Erpobdella punctata X
Helobdella stagnalis X
Illinobdella moorei X
Piscicola sp. X
Placobdella montifera X
Theromyzon rude X
OLIGOCHAETA—Earthworms, freshwater ringed worms, pot worms XXX
Chaetogaster sp. X
Triannulata montana X
Xironogiton instabilis X
MOLLUSCA—Mollusks: clams, snails, octopi
BIVALVIA—Bivalves: clams/mussels X X
Anodonta californiensis X
Anodonta compressum X
Anodonta nuttalliana X
Corbicula fluminea X X
Cyclas fluminea (=Corbicula?) X
Margaritifera margaritifera (=falcata) X
Pisidium sp. X
(Table continues)

8. AQUATIC MACROINVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
78
Benthic Invertebrates
Davis &
Cooper
(1951)
PNL
(1976-
1979)
Beak
Consul-
tants
(1980)
WPPSS
(1977,
1984-
1986)
Newell,
(1998)
Pisidium columbiana X X
Pisidium compressum X
GASTROPODA—Snails
Fluminicola sp. X X
Fluminicola nuttalliana X X X
Gyraulus parvus X
Gyraulus vermicularis X X
Goniobasis plicifera X
Limnaea sp. XXX
Lymnaea stagnalis X
Lithoglyphus sp. X
Parapholyx sp. X X
Parapholyx effusa costata X X
Parapholyx effusa neritoides X X
Parapholyx sp. X X
Planorbis sp. X
Physa sp. XXX
Physa nuttalla (=nuttallii?) X X X
Radix auricularia X
Radix japonica X X
Stagnicola apicina X X
Stagnicola nuttalliana X X
Vorticifex (Parapholyx) sp. X
Basommatophora—Freshwater limpets, pond snails
Fisherola sp. X
Fisherola nuttallii X X X X
ARTHROPODA—Arthropods: crayfish, insects, spiders, etc.
CRUSTACEA—Crustaceans
Cerophium spinicorne X
Decapoda—Crayfish, shrimp
Astasus trowbridgii X
Pacifasticus leniusculus trowbridgii X X X
Amphipoda—Scuds, sandhoppers, beach fleas X
Gammarus sp. X X X
Isopoda—Isopods: sow bugs, pill bugs
FAMILY Asellidae
Caecidotea sp. X
UNIRAMIA—Insects, millipedes, centipedes, symphylans

8. AQUATIC MACROINVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
79
Benthic Invertebrates
Davis &
Cooper
(1951)
PNL
(1976-
1979)
Beak
Consul-
tants
(1980)
WPPSS
(1977,
1984-
1986)
Newell,
(1998)
HEXAPODA (INSECTA)—Insects
Hemiptera—Bugs X
FAMILY Corixidae—Water boatmen X X
Corixa sp. X
Sigara washingtonensis X
FAMILY Gerridae—Water striders
Gerris sp. X
FAMILY Notonectidae—Backswimmers
Notonecta sp. X
Ephemeroptera—Mayflies XXX
FAMILY Baetidae XXX
Acentrella insignificans X
Baetis sp. X X X
Baetis bicaudatus X
Baetis tricaudatus X
FAMILY Baetiscidae
Baetisca columbiana [collected by Edmunds (1960) only]
FAMILY Ephemerellidae X
Ephemerella yosemite (=Drunella grandis) X X
Ephemerella inermis X
Ephemerella sp. X X X
FAMILY Ephemeridae
Ephemera simulans X
Ephoron album X X
Hexagenia sp. X X
FAMILY Heptageniidae X
Heptagenia sp. X
Heptagenia solitaria X
Nixe sp. X
Nixe simplicioides X
Stenonema sp. X X X X
Stenonema terminatum terminatum X
FAMILY Leptophlebiidae
Paraleptophlebia bicornuta X X
FAMILY Tricorythidae X X
Tricorythodes minutus X
(Table continues)

8. AQUATIC MACROINVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
80
Benthic Invertebrates
Davis &
Cooper
(1951)
PNL
(1976-
1979)
Beak
Consul-
tants
(1980)
WPPSS
(1977,
1984-
1986)
Newell,
(1998)
Plecoptera—Stoneflies X X
Arcynopteryx parallela (= Skwala americana) X
Isogenus sp. X
Perlodes americana (=Skwala americana) X
Pteronarcys californica X
Trichoptera—Caddisflies X XXXX
FAMILY Brachycentridae
Brachycentrus sp. X
Brachycentrus occidentalis X X
FAMILY Glossosomatidae X X
Glossosoma sp. X
Glossosoma parvulum X X
Glossosoma velona (= velonum?) X X X
FAMILY Hydropsychidae—Net-spinning caddisflies X X
Cheumatopsyche sp. X X X X
Cheumatopsyche campyla X X X X
Cheumatopsyche enomis (= enonis) X X X X
Cheumatopsyche logani X
Hydropsyche sp. X X
Hydropsyche (=Ceratopsyche) cockerelli X X X X
Hydropsyche californica X X X
FAMILY Hydroptilidae—Micro-caddisflies X X
Hydroptila sp. X X X
Hydroptila argosa X X X
Leucotrichia pictipes X X
FAMILY Leptoceridae—Long-horned caddisflies X X
Athripsodes annulicornis X X X
Lepidostoma strophis X X
Leptocella sp. X X
Mystacides alafimbriata X X
Oecetis sp. X
FAMILY Limnephilidae—Northern caddisflies
Limnophilus sp. (=Limnephilus ?) X
FAMILY Psychomyiidae—Tube making and trumpet-net cad. X X
Psychomyia flavida X X X
FAMILY Rhyacophilidae—Primitive caddisflies X
Rhyacophila coloradensis X X
Odonata—Damselflies and dragonflies X

8. AQUATIC MACROINVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
81
Benthic Invertebrates
Davis &
Cooper
(1951)
PNL
(1976-
1979)
Beak
Consul-
tants
(1980)
WPPSS
(1977,
1984-
1986)
Newell,
(1998)
FAMILY Gomphidae—Clubtails
Ophiogomphus sp. X
Lepidoptera—Moths and butterflies X
FAMILY Pyralidae—Snout and grass moths X X
Argyractis angulatalis X X
Petrophila confusalis X
Diptera—Flies X
FAMILY Chironomidae—Midges XXXX
SUBFAMILY Hydrobaeninae (=Chironomidae) X
FAMILY Simuliidae—Black flies or buffalo gnats X X
Simulium sp. X X X
Simulium vittatum X
FAMILY Tipulidae—Crane Flies X
Coleoptera—Beetles
FAMILY Dytiscidae—Predacious diving beetles X
Dytiscus sp. X
FAMILY Elmidae—Riffle beetles X X
FAMILY Gyrinidae—Whirligig beetles
Gyrinus sp. X
CHELICERATA
ARACHNIDA—Arachnids: spiders, mites, ticks, scorpions
Araneida—Spiders X X
Acari -- Mites
Hydracarina— Water mites X XXXX
FAMILY Hygrobatidae X
TOTAL TAXA 58 30 28 92 52
NOTE: Taxa are listed and names are spelled as they appeared in the original documents. In some cases the
current correct name has been added.

8. AQUATIC MACROINVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
82
Table 8.2. Aquatic benthic invertebrate taxa collected from tributaries to the Hanford Reach of the Columbia
River, February 1998 (Newell 1998). PHYLUM/SUBPHYLUM is in uppercase bold. CLASS/SUBCLASS
is in uppercase. Order/suborder is in lowercase bold.
Benthic Invertebrates
Hatchery
Outlet (1)
Ringold
Spring (2)
Irrigation
Return (3)
P.R. Hatchery
(4)
PLATYHELMINTHES—Flatworms, tapeworms, planarians
TURBELLARIA—Flatworms X
ANNELIDA—Earthworms, marine worms, leeches
OLIGOCHAETA—Earthworms, freshwater ringed worms X
MOLLUSCA—Mollusks: clams, snails, octopi
Gyraulus sp. X
Vorticifex (Parapholyx) sp. X
ARTHROPODA—Arthropods: crayfish, insects, spiders, etc.
Amphipoda—Scuds, sandhoppers, beach fleas
Gammarus sp. X X
Isopoda—Isopods: sow bugs, pill bugs
FAMILY Asellidae
Caecidotea sp. X
HEXAPODA (INSECTA)—Insects
Ephemeroptera—Mayflies
Baetis tricaudatus X X X X
Tricorythodes minutus X
Trichoptera—Caddisflies
Hydropsyche sp. X X X X
Hydroptila sp. X
FAMILY Limnephilidae—Northern caddisflies X
Odonata—Damselflies and dragonflies
Argia vivida X
Argia sp. X
Enallagma sp. X
Unknown X
Diptera—Flies
FAMILY Chironomidae—Midges X X X X
FAMILY Empididae—Dance flies
Hemerodromia sp. X
FAMILY Simuliidae—Black flies or buffalo gnats X X X X
FAMILY Stratiomyiidae—Soldier flies X X
Coleoptera—Beetles
FAMILY Elmidae—Riffle beetles
Optioservus sp. X X X
Zaitzevia sp. X
TOTAL TAXA = 9 7 14 7
1-Hatchery Outlet Stream = Outlet from the Ringold Fish Hatchery, river mile 355.
2-Ringold Spring = Spring stream originating from the hill east and across the road from the Ringold Fish Hatchery.
3-Irrigation Return = Irrigation return stream that enters the Columbia River adjacent to Ringold Hatchery land at river mile 354.5.
4-P.R. Hatchery = Outlet stream from the Priest Rapids Dam fish hatchery. This stream enters the Columbia River approximately 1
mile (1.6 km) downstream from Priest Rapids Dam, east bank.
Note: The sampling points for all but the spring stream at the Ringold fish hatchery were below the river’s high-water mark and within
100 m of the river.

8. AQUATIC MACROINVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
83
Table 8.3. Aquatic invertebrate taxa collected from Rattlesnake Spring. Cushing and Rader (1982) worked
with a single taxon, Callibaetis (Ephemeroptera), that is not listed in this table. PHYLUM/SUBPHYLUM is
in uppercase bold. CLASS/SUBCLASS is in uppercase. Order/suborder is in lowercase bold.
Benthic Invertebrates
Gaines
1987 a,b
Newell
1998
Pickel
2000
Newell
2003
ANNELIDA—Earthworms, marine worms, leeches
OLIGOCHAETA—Earthworms, freshwater ringed worms X X
MOLLUSCA—Mollusks: clams, snails, octopi
Physella sp. X X
Pisidium sp. X X X
Radix auricularia X X
Fisherola sp. X
ARTHROPODA—Arthropods: crayfish, insects, spiders, etc.
Amphipoda—Scuds, sandhoppers, beach fleas
Hyalella azteca X X X
HEXAPODA (INSECTA)—Insects
Hemiptera—Bugs
FAMILY Belostomatidae—Giant water bugs
Belostoma bakeri X
FAMILY Corixidae—Water boatmen
Cenocorixa bifida hungerfordi X
Corisella inscripta X
Graptocorixa californica X X
Hesperocorixa laevigata X
Sigara alternata X X
FAMILY Gerridae—Water striders X
FAMILY Notonectidae—Backswimmers X X
Notonecta kirbyi X
Notonecta undulata X
Notonecta sp. X
Ephemeroptera—Mayflies
Baetis sp. X X X
Callibaetis sp. X X
Paraleptophlebia sp. X
Tricorythodes sp. X
Trichoptera—Caddisflies
Cheumatopsyche sp. X X
Hesperophylax sp. X X X
Lepidostoma sp. X
Limnephilus sp. X
Parapsyche sp. X
(Table continues)

8. AQUATIC MACROINVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
84
Benthic Invertebrates
Gaines
1987 a,b
Newell
1998
Pickel
2000
Newell
2003
Odonata—Damselflies and dragonflies
FAMILY Aeshnidae—Darners X
Aeshna multicolor (adult) X
Aeshna umbrosa(adult) X
Aeshna sp. X
Archilestes californica X
FAMILY Coenagrionidae—Narrow-winged damselflies
Argia tibialis X
Argia sp. X X X
Enallagma sp. X
Diptera—Flies
FAMILY Chironomidae—Midges X X X X
Chaetocladius sp. X
Chironomus sp. X
Heleniella sp. X
Polypedilum sp. X
Thienemannimyia sp. X
FAMILY Dixidae—Dixid midges X X X
FAMILY Empididae—Dance flies X X
FAMILY Psychodidae—Moth flies and sand flies X X
FAMILY Simuliidae—Black flies or buffalo gnats X X X X
Simulium sp. X X X
FAMILY Tabanidae—Horse flies and deer flies X
FAMILY Tipulidae—Crane Flies
Dicranota sp. X
Coleoptera—Beetles
FAMILY Dryopidae—Long-toed water beetles X
FAMILY Dytiscidae—Predacious Diving Beetles X
Hydaticus sp. X X
Unknown X
FAMILY Elmidae—Riffle beetles
Optioservus sp. X
Rhizelmis sp. X
FAMILY Gyrinidae—Whirligig Beetles X X
FAMILY Hydrophilidae—Water scavenger beetles X
ARACHNIDA—Arachnids: spiders, mites, ticks, scorpions
Acariformes—Mite-like mites X
TOTAL TAXA 20 30 17 21

8. AQUATIC MACROINVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
85
Table 8.4. Aquatic invertebrate taxa collected from Snively Spring. PHYLUM/SUBPHYLUM is in
uppercase bold. CLASS/SUBCLASS is in uppercase. Order/suborder is in lowercase bold.
Benthic Invertebrates
Gaines
1987a, b
Newell
1998
Pickel
2000
Newell
2003
MOLLUSCA—Mollusks: clams, snails, octopi
PELECYPODA (=BIVALVIA)
FAMILY Sphaeriidae—Fingernail clams X
ARTHROPODA—Arthropods: crayfish, insects, spiders, etc.
Decapoda—Crayfish, shrimp
Pacifasticus leniusculus X X
Amphipoda—Scuds, sandhoppers, beach fleas
Gammarus sp. X X X
HEXAPODA (INSECTA)—Insects
Ephemeroptera—Mayflies
Baetis sp. X X X X
Paraleptophlebia sp. X
Tricorythodes sp. X
FAMILY Heptageniidae X
Trichoptera—Caddisflies
Cheumatopsyche sp. X X X X
Parapsyche sp. X X X
Odonata—Damselflies and dragonflies
Argia sp. X X
Argia tibialis X
Diptera—Flies
FAMILY Chironomidae—Midges X X X X
Chaetocladius sp. X
Chironomus sp. X
Heleniella sp. X
Polypedilum sp. X
Thienemannimyia sp. X
FAMILY Dixidae—Dixid midges X X X X
FAMILY Empididae—Dance flies X X
FAMILY Psychodidae—Moth flies and sand flies X
FAMILY Simuliidae—Black flies or buffalo gnats X X X X
Simulium sp. X X X
FAMILY Tabanidae—Horse flies and deer flies X
FAMILY Tipulidae—Crane Flies X X X X
Dicranota sp. X
Coleoptera—Beetles
FAMILY Curculionidae—Weevils or snout beetles X
FAMILY Elmidae—Riffle beetles X
FAMILY Hydrophilidae—Water scavenger beetles X X
TOTAL TAXA 18 14 11 13

8. AQUATIC MACROINVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
86
Table 8.5. Aquatic Macroinvertebrates from Benson, Snively, and Rattlesnake Springs collected and
identified by Pickel (2000). PHYLUM/SUBPHYLUM is in uppercase bold. CLASS/SUBCLASS is in
uppercase. Order/suborder is in lowercase bold.
Benthic Invertebrates Benson Snively Rattlesnake
MOLLUSCA—Mollusks: clams, snails, octopi
FAMILY Lymnaeidae—Fisherola sp. X
FAMILY Sphaeriidae—Fingernail clams X X X
ARTHROPODA—Arthropods: crayfish, insects, spiders, etc.
Decapoda—Crayfish, shrimp
Pacifasticus leniusculus X
Amphipoda—Scuds, sandhoppers, beach fleas
Gammarus sp. X
Hyalella azteca X
HEXAPODA (INSECTA)—Insects
Hemiptera—Bugs
FAMILY Corixidae—Water boatmen, Graptocorixa sp. X
Ephemeroptera—Mayflies
Baetis tricaudatus X X
Callibaetis sp. X
Paraleptophlebia sp. X
FAMILY Heptageniidae X
Trichoptera—Caddisflies
Cheumatopsyche sp. X
Parapsyche sp. X
Lepidostoma sp. X
FAMILY Limnephilidae—Northern caddisflies X
Hesperophylax sp. X
Odonata—Damselflies and dragonflies
FAMILY Aeshnidae—Darners X
FAMILY Coenagrionidae—Narrow-winged damselflies, Argia sp. X X
Diptera—Flies
FAMILY Chironomidae—Midges X X X
FAMILY Dixidae—Dixid midges, Meringodixa sp. X X X
FAMILY Psychodidae—Moth flies and sand flies, Pericoma sp. X
FAMILY Simuliidae—Black flies or buffalo gnats X X X
FAMILY Tipulidae—Crane Flies X X X

8. AQUATIC MACROINVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
87
Benthic Invertebrates Benson Snively Rattlesnake
Coleoptera—Beetles
FAMILY Curculionidae—Weevils or snout beetles X X
FAMILY Dryopidae—Long-toed water beetles X
FAMILY Dytiscidae—Predacious Diving Beetles X
FAMILY Elmidae—Riffle beetles, Optioservus sp. X
FAMILY Elmidae—Riffle beetles, Rhizelmis sp. X
FAMILY Hydrophilidae—Water scavenger beetles X X
ARACHNIDA – Arachnids: spiders, mites, ticks, scorpions
Acariformes—Mite-like mites X
TOTAL TAXA 16 11 17
Newell (1998) 10 taxa; and Newell (this study) 11 taxa. The following taxa previously collected by Gaines
(1987a, b) and/or by Newell (1998) were not found by Newell in the 2002 study: Paraleptophlebia,
Tricorythodes, Elmidae, Hydrophilidae, Argia tibialis, Dicranota sp., Tabanidae, and perhaps some
Chironomidae. The 2002 study found the previously undetected Diptera family Psychodidae.
Pickel (2000) sampled all three springs prior to the 24 Command Fire of June–July 2000 (Table 8.5 has more
specific taxonomic entries than Tables 8.3 and 8.4 for Pickel’s collections). He noted 16 taxa in Benson
Spring, 11 in Snively Spring and 17 in Rattlesnake Spring. When compared to Newell’s (1998) pre-fire
sampling, the results for Pickel’s and Newell’s results are: Snively Spring—11 and 14 taxa respectively;
Rattlesnake Spring—17 and 30 taxa respectively. Important differences between the two studies at Snively
Spring are that Pickel (2000) found new taxa of Sphaeriidae, Heptageniidae, and Curculionidae, but did not
collect Pacifasticus leniusculus, Parapsyche sp., Argia spp., Simulium sp., Dicranota sp., nor Elmidae (Table
8.4).
For Rattlesnake Spring, the differences between Pickel (2000) and Newell (1998) are as follows. Pickel found
the following new taxa: Fisherola sp., Lepidostoma sp., Parapsyche sp., Dixidae, Psychodidae, Dryopidae,
Elmidae (2 genera), and Acariformes. Newell found the following taxa not noted by Pickel: Oligochaeta,
Physella sp., Radix auricularia, Belostoma bakeri, Corixidae (5 species), Gerridae, Notonectidae (2 species),
Baetis sp., Cheumatopsyche sp., adults of three species in the family Aeshnidae (Pickel did note collecting the
family Aeshnidae), perhaps Simulium sp., Dytiscidae (2 species), and Gyrinidae (Table 8.3). Some of the
Hemiptera are not technically benthic organisms, but are aquatic insects.

8. AQUATIC MACROINVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
88
OVERVIEW OF SELECTED AQUATIC INSECT ORDERS
Ephemeroptera (Mayflies)
Several of the taxa of adult mayflies that were captured in 1998 in the vicinity of the Columbia River (within
1 mile/1.6 km) but not noted recently from the Hanford Reach are listed in Table 8.6. These catches were far
enough from the river to raise questions as to their habitat and origin. These species may potentially occur in
the Reach; other possible origins include the Yakima River and nearby irrigation ditches, ponds, etc.
Ephoron album is very abundant in the nearby Yakima River and was collected in the Columbia River by
Davis and Cooper (1951). In late July and early August, huge numbers of adults of this mayfly are attracted to
light sources in Richland, Washington, during the evening hours. Over many years of collecting, the author
has not caught nymphs of this species in the Hanford Reach, nor has he collected adults immediately adjacent
to the Reach. Davis and Cooper also collected nymphs of the largest U.S. mayfly, Hexagenia; more recently,
this species has been collected in Lake Wallula but not in the Hanford Reach (pers. obs.). Since nymphs of
both of these species are burrowers, their specialized habitat could have been missed in Newell’s sampling of
the Reach but collected by Davis and Cooper with their bottom-dredge sampling procedure.
Fourteen mayfly species in 8 genera were collected by Newell (1998), and Davis and Cooper (1951) listed 7
species in 6 genera from the river (Table 8.1). Three of the genera reported by Davis and Cooper (1951) were
collected by Newell (1998): Ephemerella, Stenonema, and Baetis. Paraleptophlebia bicornuta, collected in
small streams in southeastern Washington, was not found in the Hanford Reach. The species Ephemerella
yosemite is now known as Drunella grandis and is common in cold mountain streams in Washington and
elsewhere in the west, but it has not been collected recently in the Hanford Reach. Newell (1998) found a
number of species of mayflies previously unreported from the Hanford Reach: Acentrella insignificans, Baetis
bicaudatus and B. tricaudatus, Ephemerella inermis, Ephemera simulans, Heptagenia solitaria and H. sp.,
Nixe simplicioides and N. sp., Stenonema terminatum, and Tricorythodes minutus. During July–September in
the Richland area, large numbers of adults of Heptagenia, Nixe, Ephemerella, Stenonema, and Tricorythodes
are commonly encountered adjacent to the Reach shoreline. Adults of the burrowing mayfly, Ephemera
simulans, were encountered only once by this author in 1998, swarming near the river shoreline at Leslie
Groves Park on a warm summer evening at dusk.
Edmunds (1960) reported a record of a rare mayfly, Baetisca columbiana, from the Columbia River, collected
near Pasco, Franklin County, Washington, in 1948. No one else has collected or confirmed the presence of
this species in the subsequent 50 years.
Table 8.6. Taxa of adult Ephemeroptera (mayflies) captured by Newell in 1998 in the vicinity of the
Columbia River, Richland, WA.
Callibaetis fluctuans (Eaton)
Callibaetis montanus (Eaton)
Callibaetis pictus (Eaton)
Camelobaetidius sp.
Ephoron album (Say)
Heterocloeon sp.
Labiobaetis propinquus (Walsh)

8. AQUATIC MACROINVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
89
Hemiptera (True Bugs)
Table 8.7 includes Hemiptera collection records from R. Zack, Washington State University, from the
Hanford Site (Benton County) during and prior to 1998 (R. Zack pers. comm.). Adult Corixidae and
Notonectidae are excellent flyers, and their powers are excellent, thus they may appear in any suitable habitat.
The immatures and/or adults of these species may or may not live in the Columbia River or other Hanford
water bodies.
Odonata (Dragonflies and Damselflies)
Table 8.8 lists Odonata nymphs and adults captured by Newell (1998) or R. Zack (pers. comm.) in or near the
Columbia River, Rattlesnake Spring, Snively Spring, and other locations on the Hanford Site. Gaines (1987a,
b) listed only Argia tibialis from both spring streams, but Paulson (1998) does not list this species from
Benton County. The list of taxa collected by Newell and Zack is more diverse than previously reported,
probably because other researchers did not sample for adult Odonata. Odonata adults are excellent fliers and
can migrate great distances from larval habitats.
Table 8.7. Hemiptera collected on or near the Hanford Site (Zack pers. comm.). Species are listed by the
closest water sources as follows: Hanford Reach of the Columbia River (CR), Rattlesnake Spring (RS),
Snively Spring (SS), and Gable Mountain Pond (GP), a temporary artificial pond on Central Hanford.
TAXA CR RS SS GP
FAMILY Belostomatidae—Giant water bugs
Belostoma bakeri Montandon X
FAMILY Corixidae—Water boatmen
Cenocorixa bifeda hungerfordi Landsbury X X X X
Cenocorixa wileyae (Hungerford) X
Corisella decolor (Uhler) X
Corisella inscripta (Uhler) X X X
Hesperocorixa laevigata (Uhler) X X X X
Sigara alternata (Say) X X X
Sigara washingtonensis Hungerford X X
FAMILY Gerridae—Water striders
Gerris buenoi Kirkaldy X X
Gerris incurvatus Drakes & Hottes X X
Gerris remigis Say X X
Limnoporus notabilis (Drake & Hottes) X
FAMILY Notonectidae—Backswimmers
Notonecta kirbyi X X
Notonecta undulata Say X X
Notonecta unifasciata X X
TOTAL TAXA 7 12 9 4

8. AQUATIC MACROINVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
90
Plecoptera (Stoneflies)
This study collected no stoneflies in the river, tributaries, or the spring streams, and no adults were captured
anywhere on the Hanford Site. Davis and Cooper (1951) found three species in the river. Only two other
studies (PNL 1979a,b,c, WPPSS 1977) noted Plecoptera in their samples. No stoneflies have been captured in
the Hanford Reach since 1979.
Diptera (Flies)
The Diptera are a difficult group to identify beyond the family level in most cases. Becker (1972a,b) did
identify one black fly to species, Simulium vittatum. Gaines (1987a, b) identified Chironomidae larvae to
genus. Zack (1998) has compiled a list of shoreflies (family Ephydridae) of the Hanford Site from past years
of sampling. The diversity of Diptera is great, but only the Chironomidae and Simuliidae are abundant in the
Hanford Reach and the springs of the ALE Reserve.
Table 8.8. Odonata (adults and nymphs) captured in or near the following locations on the Hanford Site by
Newell (1998) and Zack (1998, pers. comm.). Species are listed by the closest water sources as follows:
Columbia River (CR), Rattlesnake Spring (RS), Snively Spring (SS), or other locations on the
Hanford Site (H).
TAXA CR RS SS H
Aeshna californica Calvert X X
Aeshna multicolor Hagen X
Aeshna umbrosa Walker X
Aeshna sp. X
Ophiogomphus sp. X
Amphiagrion abbreviatum (Selys) X
Argia sp. X X
Argia vivida X X X
Argia tibialis X X
Enallagma cyathigerium (Charpentier) X
Enallagma carunculatum Morse X
Ishnura cervula Selys X
Ishnura perparva Selys X
Libellula pulchella Drury X
Archilestes californica McLachlan X
Total Taxa 3 12 3 2

8. AQUATIC MACROINVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
91
ORIGIN OF ADULT TRICHOPTERA (CADDISFLIES)
The caddisfly fauna of the Columbia River and Rattlesnake and Snively Springs is rich and varied. Gaines
(1987a, b) has published the most complete benthic faunal list from these two springs. He reported two and
three genera of caddisflies, respectively, from the spring streams’ benthic sampling. Newell et al. (2001) and
Strenge (pers. comm.) found 21 genera and 35 species of adults near Rattlesnake Spring and 2 genera near
Snively Spring by light trapping. The increase in the faunal list from Rattlesnake Spring was due largely to
the light trap sampling of adults after dark (Table 8.9). Davis and Cooper (1951) reported 17 taxa of
caddisflies from benthic samples from the river, 11 of which were among the 13 taxa collected by Newell et
al. (2001).
Larvae of many of the taxa of adult Trichoptera that were collected in light traps between 1998 and 2001 have
never been collected from any of the spring streams. Immatures of many of the adult taxa collected near the
springs are, however, common in the Columbia River. This leads to speculation that some of the adult
specimens collected near the spring streams originated from the river. This was partially confirmed by
sampling for adults in the dunes area between the river and the spring streams. Sixteen taxa of adult
caddisflies were caught in the dunes, where no water is available, indicating that the adults were dispersing
from their aquatic source of origin.
Table 8.9. Caddisfly adults collected using ultraviolet and mercury vapor light trapping and Lepidoptera
pheromone traps. Sources include Newell et al. (2001), Pickel (2000) for the Benson Spring area, unpublished
data from D. Strenge (pers. comm.) for 2001 and 2002 from the springs and the dunes area, and casual
sampling by Newell and others from the Hanford Reach. The dune area is located on Central Hanford about 5
miles west of the Columbia River near the Energy Northwest power plant.
TAXAFamily/Genus/Species
Rattlesnake
& Snively
Springs
1999
Rattlesnake
& Snively
Springs
2001
Benson
Spring
1999–2000
Dunes 1999
& 2001
Hanford
Reach
1998–
2002
FAMILY Brachycentridae
Amiocentrus aspilus (Ross) X
Brachycentrus americanus (Banks) X?
FAMILY Glossosomatidae
Culoptila cantha (Ross) X X X
Glossosoma parvulum Banks X
Glossosoma velonum Ross X X X X
Protoptila coloma Ross X X
Protoptila erotica Ross X X X
FAMILY Hydropsychidae—Net-spinning
caddisflies
Cheumatopsyche campyla Ross X X X X X
Cheumatopsyche gelita Denning X
Ceratopsyche oslari Banks X
Hydropsyche californica Banks X X X X
Hydropsyche cockerelli Banks X X X X X
Parapsyche almota Ross X X
(Table continues)

8. AQUATIC MACROINVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
92
TAXAFamily/Genus/Species
Rattlesnake
& Snively
Springs
1999
Rattlesnake
& Snively
Springs
2001
Benson
Spring
1999–2000
Dunes 1999
& 2001
Hanford
Reach
1998–
2002
FAMILY Hydroptilidae—Micro-caddisflies
Hydroptila arctica Ross X
Hydroptila argosa Ross X X X X
Hydroptila modica Mosely X
Hydroptila xera Mosely X
Leucotrichia pictipes (Banks) X
FAMILY Leptoceridae—Long-horned caddisflies
Ceraclea latahensis (Smith, S.D.) X
Ceraclea annulicornis (Stephems) X
Oecetis avara (Banks) X X X
Oecetis immobilis (Hagen) X
Oecetis inconspicua (Walker) X X X
Trianedes baris Ross X
Trienodes tardus Milne X X
Ylodes frontalis (Banks) X X
Ylodes reuteri (MacLaughlin) X
Nectopsyche sp. X X
Nectopsyche lahontanensisHaddock X X
Polycentropus cinereus (Hagen) X X
FAMILY Limnephilidae—Northern caddisflies
Hesperophylax designatus (Walker) X X
Limnephilus abbreviatus Banks X
Limnephilus aretto Ross X
Limnephilus assimilis (Banks) X X
Limnephilus diversus (Banks) X
Limnephilus frijole Ross X X
Limnephilus sitchensis (Kalenati) X
Limnephilus spinatus Banks X X
FAMILY Psychomyiidae—Tube making and
trumpet-net caddisflies
Psychomyia flavida Hagen X X X X
FAMILY Lepidostomatidae
Lepidostoma cinereum (Banks) X X
TOTAL TAXA 26 28 3 16 7

8. AQUATIC MACROINVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
93
WILDFIRE EFFECTS ON SPRING-STREAM INVERTEBRATES
Visits to Rattlesnake Spring subsequent to the 2000 wildfire and two years later revealed a severely impacted
stream and devastated riparian zone. The wildfire burned much of the riparian vegetation and deposited ash
and charred material into the stream. Vegetation not burned was killed by the heat and much of this material
fell into the stream channel. With the surrounding soil unprotected and no riparian buffer zone, winds have
blown sand, silt, ash, and dead vegetation into the stream. The result is a great increase in sediment, reduced
flow velocities, and dramatic change in substrate composition. This detritus material cannot be flushed from
the stream due to the large amount of dead vegetation now restricting stream flow. Bottom sampling revealed
a tremendous amount of silt and large amounts of particulate organic matter. Bottom samples also revealed a
decrease in diversity and a reduction in numbers of organisms compared to sampling conducted in 1998 and
2000 (Table 8.3), while some taxa such as the Chironomidae (midges), Simuliidae (black flies or buffalo
gnats), Amphipoda (scuds, sandhoppers, beach fleas), and the fingernail clam Pisidium (Sphaeriidae)
remained high. Chironomidae and Amphipoda are very tolerant of extreme environmental conditions and
adaptable, but the high populations of filter feeders such as Simuliidae and Pisidium are unexpected because
of the huge amounts of sediments that could disrupt their filter feeding habits. The huge sediment additions to
the substrate, and reduced flows could smother the small Pisidium clams.
The benthic fauna of Snively Spring has changed little from the pre-fire studies, although no aquatic beetles
were caught in 2002 sampling (Table 8.4). Snively Spring was apparently less impacted than Rattlesnake
Spring by the fire. This may be attributable to the location of the spring streams and their stream channel
configuration. Snively Spring is located primarily in a steep canyon. This may have reduced wind effects and
lessened input of detritus from outside of the stream channel. The Snively stream channel is narrow and V-
shaped; this has prevented much of the dead vegetation from reaching and restricting stream flow. Thus,
flows in Snively have been maintained much as before the fire. Silt, ash, and debris that might have reached
the stream would have been washed downstream. This seems to be born out by the large amounts of silt and
debris found in the lower 200 m of the Snively Spring channel.
STATUS OF THE PACIFIC CRAYFISH, PACIFASTICUS LENIUSCULUS, IN THE HANFORD REACH
One objective of this small study in 2002 was to increase the sampling effort in an attempt to determine the
status and condition of the Pacific crayfish, Pacifasticus leniusculus, in the Hanford Reach. This concern
arose from Newell’s (1998) report that noted not a single intact crayfish specimen was captured or seen,
although body parts were found, while previous studies noted an incredible abundance of crayfish in the
Columbia River (Coopey 1953). This portion of the 2002 study was merely a few days in length but involved
some sampling efforts that differed from previous studies. Sampling was conducted in the late winter prior to
river fluctuations, again in late spring, and with traps. The traps failed to attract crayfish, but sampling at low
and steady river levels in late winter revealed large numbers of crayfish in many size classes. Nearly every
rock harbored a crayfish beginning at the water’s edge and out as far as the surveyor could wade. Sampling in
May revealed no crayfish. Perhaps this crayfish has adapted to the daily river fluctuations by staying in deeper
water except when flows are constant over long periods as during the winter.
Crayfish populations are present in both Benson and Snively Springs. Specimens caught in these springs do
not achieve the large size of Hanford Reach specimens.
STATUS OF THE WESTERN PEARL MUSSEL, MARGARITINOPSIS FALCATA, IN THE HANFORD REACH
Freshwater mussels are mollusks in the class Bivalvia (Stock 1996). There are seven species of native large
freshwater bivalves in Washington state, but literature on their ecology and distribution is limited. The seven
species belong to the genera Anodonta and Gonidea (Unionidae) and Margaritinopsis (Margaritiferidae).
Mussels will not occur in streams where the substrate is substantially disturbed by torrents (Toy 1998). Pearly

8. AQUATIC MACROINVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
94
freshwater mussels of the order Unionoida reproduce by releasing immature mollusks called glochidia into
the stream. These glochidia must attach to the gills of a fish within a few days in order to survive. They
eventually fall off of the host as a small mussel. Both of these events exhibit high mortalities, which are
compensated for by production and release of huge numbers (millions) of glochidia and by long-lived adults.
Margaritinopsis is usually found in cold, well oxygenated, oligotrophic (low in nutrients) waters with a sand
and gravel substrate. Distribution is affected by current velocity, temperature, particle size of substrate, water
chemistry, timing and nature of organic inputs (Toy 1998), floods and river stability (Vannote and Minshall
1982), and availability of suitable hosts for their glochidia (usually young fish of the family Salmonidae-trout,
char, and salmon). Under optimal conditions, Margaritinopsis can form extensive beds. Murphy (1942)
estimated over 20,000 individuals in a three-quarters-mile channel of the Truckee River in California.
Unfavorable fluvial processes and lithology can work to confine Margaritinopsis to localized places in a
river, such as in protected areas behind large boulders (Vannote and Minshall 1982) or behind large woody
debris (Stock 1996). This mussel prefers areas of stable substratum and current velocities sufficient to prevent
deposition of silt and sand. Stock (1996) found mussels predominately in cobble substratum with large logs
and boulders present, which provide substrate stabilization during flood events. DiMaio and Corkum (1995)
also noted that Unionidae bivalves are adversely affected by unstable hydrologic regimes. Stock (1996)
believed that mussel habitat corresponded to that of juvenile forms of their host fishes, primarily salmonids.
The western pearl mussel, Margaritinopsis falcata (Gould), is endemic to the North American states or
provinces west of the Rocky Mountains, including California, Idaho, Montana, Nevada, Oregon, Washington,
and British Columbia. Glochidia of M. falcata are highly host specific (Bauer et al. 1991) and are generally
restricted to the salmonid family, especially Chinook salmon, cutthroat trout, steelhead, and coho salmon.
Stream velocities affect this mussel with stream gradients of 1.4% containing mussels and those averaging
2.4% absent of mussels. Koenig (2000) determined that M. falcata can adjust to natural variable stream
conditions, but these adaptations may be inadequate to compensate for larger scale stream habitat degradation.
M. falcata is one of the most common species of freshwater mussels in the Pacific Northwest. It is closely
related to, and until recently was considered a subspecies of, Margaritifera margaritifera (L.) (Burch 1972),
which is a circumpolar species found in northern Europe, Russia, Great Britain, and the eastern United States
and formerly known as Margaritana margaritifera (Elrod 1902). M. falcata is found in west coast drainages
from California to Alaska, with a suspect disjunct population occurring in the upper Missouri drainage in
Montana (Clarke 1981, Stober 1972). Smith (2000) elevated this species to a new genus, Margaritinopsis, for
all specimens in Pacific Northwest coastal drainages.
M. falcata may be one of the longest living freshwater invertebrates. The oldest known specimens have been
aged at greater than 90 years (Toy 1998), 100 years (Vannote and Minshall 1982), and >100 years old (Stock
1996).
Native Americans have been harvesting M. falcata from the Columbia River drainage for as long as 5000–
7000 years (Toy 1998, and T. Marceau pers. comm.). Lyman (1980) noted 13 archaeological sites along the
Columbia and Snake Rivers, and Round Butte in Central Oregon. Many of these sites contained remains of M.
falcata and dated from nearly 9000 years before present.
While once very abundant in this stretch of the Columbia River, recent collecting efforts suggest that the
population of M. falcata has drastically declined in the Hanford Reach and probably in much of the Columbia
and Snake Rivers inundated by dams. The only recent collection of this taxon on the Hanford Reach is by
Newell (2003), who discovered a dead specimen of M. falcata on the shore of the Columbia River at Leslie
Groves Park in Richland, Benton County, during August 2000. This shell was recently dead since it had fresh
muscle flesh attached to one of the unbroken shell halves. A search of the immediate area found three live
specimens in about 6–10 inches of water. All were about the same size, approximately 100 mm in length. The
river flow this time of year is typically very reduced with little diurnal or diel fluctuations and relatively low
discharge. This location is not far from the upper reaches of the influence of Lake Wallula. The substratum in
this side channel is sand and gravel with relatively modest current flows. Based on other studies, these

8. AQUATIC MACROINVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
95
individuals could be 60+ years of age and would have hatched before any of the Columbia River dams were
constructed. The author has sampled, fished, and recreated on the Hanford Reach for 15 years and has
extensively observed aquatic life in and along the river; if even a modest population of these bivalves exists in
the Hanford Reach, it is likely more shells and live specimens would have been found. Even in the presence
of many young host specimens of Chinook salmon, some factor(s) has caused an apparent drastic decline in
this species. Based on the substrate and flow requirements of this species, and given the large daily and
seasonal water level fluctuations on the Hanford Reach, substrate conditions resulting from this flow regime
would be detrimental for the adults and probably more so for the young bivalves. It is possible that the huge
population of the non-native Asiatic clam, Corbicula fluminea, in the Reach may also have a detrimental
influence.
Williams et al. (1993) listed this species as one of undetermined conservation status due to a lack of
knowledge of this species. Anderson (2002) attributes the decline of Margaritifera and other mollusks to the
presence of dams. Dams impound flowing habitat, reducing water velocities as well as inundating diverse
substrates with fine sediments (Bogan 1993). Mussels downstream from dams are subject to scouring effects
from the outflow, which can create unstable substrates as well as inundation. Frest and Johannes (1995) list
the following actions as threats to this species: extensive diversion of streams, hydroelectric and water supply
projects, heavy nutrient enhancement, sedimentation, and unstable substrate. These and other factors likely
have greatly reduced populations in the main stem Snake and Columbia Rivers (Frest and Johannes 1995).
Frest and Johannes (1995) did not recommend federal or state listing of the species, although they believe the
species should be considered sensitive. They recommend further work to document range changes. They note
that populations showing repeated reproduction (at least several age classes) are now the exception rather than
the rule.
Newell (2003) lists historic and contemporary collection records for Margaritanopsis falcata and provides a
partial bibliography of literature regarding this taxon.
Summary and Conclusions
The macroinvertebrate fauna of the Hanford Reach has changed over the last 50 years. Records of aquatic
invertebrate catches (Table 8.1) indicate that mayfly diversity has increased; stoneflies have disappeared;
caddisfly diversity and abundance remain high; Odonata, Hemiptera, Lepidoptera, and Coleoptera are rare;
and Diptera diversity remains relatively constant. Recent surveys found that the population of the crayfish,
Pacifasticus leniusculus, remains high, but the western pearl mussel, Margaritinopsis falcata, seems to have
nearly disappeared from its past high densities. Taxonomic revisions of the mollusks make it difficult to
compare catches from numerous studies conducted over several decades, and no voucher specimens are
available for study. The one healthy mollusk population is that of the introduced exotic Asiatic clam,
Corbicula fluminea, which is extremely abundant in the Hanford Reach. Impacts of the huge population of
this mollusk on other benthic fauna is unknown.
One problem in comparing current data with data collected over 50 years ago is revision of taxonomy. Taxa
have been split (e.g., the mayfly families Ephemerellidae and Baetidae) making some comparisons impossible
without voucher specimens to examine. In some instances the early studies were only able to identify most
benthic organisms to genus. Apparently adult specimens were not a priority, and thus identification to species
was not possible. Additionally, sampling techniques and sampling intensity have varied with different studies.
Benthic macroinvertebrate diversity in the spring streams of the ALE Reserve has changed over the last 15
years. In Rattlesnake Spring, the mayfly genera Paraleptophlebia and Tricorythodes and the caddisfly genus,
Limnephilus, have not been captured since 1987, nor has any hydrophilid beetle or tabanid fly (Table 8.3).
Similarly, Paraleptophlebia and Tricorythodes have not been caught since 1987 from Snively Spring, nor has
any tabanid fly (Table 8.4). It is impossible to compare the status of some groups prior to Newell (1998) since
previous studies did not collect some taxa (Hemiptera, Amphipoda, and Mollusca). Pickle (2000) found some

8. AQUATIC MACROINVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
96
taxa previously unreported from Rattlesnake or Snively Springs and found diversity in Benson (Bobcat)
Spring to be similar to the other two spring streams (Table 8.5).
The streams of both Rattlesnake and Snively Springs were impacted by the fire of June–July 2000 that
engulfed much of the Hanford Site. Rattlesnake Spring was the most severely impacted by a combination of
ash, silt, charred wood, and dead and wind-blown vegetation detritus.
Recent studies by Newell have found new taxa of Ephemeroptera, Trichoptera, and Odonata from the Hanford
Reach, and new taxa of Odonata, Hemiptera and Coleoptera from one or more of the spring streams of the
ALE Reserve. Many of the Trichoptera in Table 8.9 represent first-time records for the Hanford Site. The
tributaries of the Hanford Reach had never been sampled before Newell’s (1998) study.
Recommendations
Recommendations for future research:
• Benthic sampling in Benson, Snively, and Rattlesnake Springs should occur periodically to document
the status of invertebrate populations and monitor recovery from the 2000 wildfire.
• Periodic monitoring of the morphology, chemistry, and temperature of the ALE spring streams should
be initiated to establish baseline conditions and to evaluate changes over time. Stream profile
monitoring can help assess the impacts of erosion and sedimentation on these spring channel
ecosystems.
• Studies of select groups of aquatic macroinvertebrates should be designed with consideration of the
methods and season of earlier studies in order to facilitate comparability between studies and thus
better evaluate changes in the benthic fauna over time.
• More intensive sampling of the Hanford Reach and its shoreline should be considered to create a
valid current species list. Long-term, seasonal studies of the Reach are needed to develop baseline
data that can be used to monitor the effects of both natural and anthropogenic disturbances, such as
unstable hydrological regimes, on benthic fauna over time.
• Comprehensive surveys for the western pearl mussel, Margaritinopsis falcata, should be conducted to
determine whether isolated populations of this formerly abundant mussel exist within the Hanford
Reach.
Recommendations for management:
• Rattlesnake and Snively Springs are fragile ecosystems that have been greatly disturbed by the
wildfire of 2000. The springs are ecologically important in that they provide water and some
remaining riparian habitat to animals, and they provide rare habitat for a diverse assemblage of
benthic fauna in an otherwise arid environment. Additional disturbances to these fragile ecosystems
should be avoided.
• Management plans designed to protect salmon should include measures to protect aquatic insects,
which are the main food for young chinook salmon (Dauble et al. 1980).

BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
97
9. Terrestrial Invertebrates
Richard S. Zack, Dennis L. Strenge, and Peter J. Landolt
Introduction
The Hanford Site serves as a refuge for many insects that were probably once common throughout the
Columbia Plateau but today are confined to the few remaining undisturbed tracts of land. Terrestrial
invertebrates at Hanford have been the subject of several general surveys (ERDA 1975, Rogers 1979).
Specific groups of insects studied at Hanford include darkling beetles (Tenebrionidae) (Rickard et al. 1974,
Rickard and Haverfield 1965, and Rogers et al. 1978), ground dwelling beetles (Rickard 1970), and
grasshoppers (Sheldon and Rogers 1978). More recently, the Hanford Site was the subject of relatively
intensive arthropod surveys (principally insects) from 1994 to 2000. Results of these studies have been
reported in Soll et al. (1999) and in a number of scientific publications (Grissell and Zack 1996, Newell et al.
2001, O’Brien and Zack 1997, Strenge and Zack 2003, Zack 1998, Zack and Looney 2001, Zack et al. 1998,
and Zack et al. 2001).
The following section summarizes work on the biodiversity of terrestrial invertebrates during 2002–2003 at
this critical site. Some of the information included in this report refers to specimens collected during previous
Hanford studies (Soll et al. 1999) but which had not been identified until recently. Full details are presented in
Zack et al. (2003).
Purpose and Scope
The current study was essentially a continuation of previous entomological diversity surveys conducted on the
Hanford Site from 1994 to 2000. The primary goal was to add to developing knowledge regarding selected
taxonomic groups, to extend the inventory to groups not previously examined, and to examine habitats on the
Wahluke and Saddle Mountain Units that had not been sampled during previous studies.
The investigation focused on ground dwelling beetles and on moths, as these were groups on which previous
biodiversity studies had concentrated and groups for which the investigators could perform identifications
without relying on outside consultants. These taxa are studied elsewhere by those conducting biological
diversity studies, and the current study will enable comparisons with work from other regions and habitats.
Caddisflies were collected in order to supplement studies in the Rattlesnake and Snively Springs areas of ALE
(Newell 2003, Newell et al. 2001).
Methods
Three series of 10 pitfall traps were established on the North Slope of the Hanford Site on the Hanford Reach
National Monument during April 2002. Pitfall trapping locations were placed in habitats favorable to the
collection of diverse arthropod assemblages and in areas that were comparable to sites established on the ALE
Reserve and Central Hanford during the 1994–2000 studies. Site 1 (Coordinates [UTM NAD27]: E - 298338 /
N - 5175107) is located in the Saddle Mountain Unit in a big sagebrush/cheatgrass area with sandy soil. Site 2
(Coordinates E 301905 / N - 5173935) is also located on the Saddle Mountain Unit near the end of an
irrigation runoff. The site is on sand with little cheatgrass and diverse native vegetation including some

9. TERRESTRIAL INVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
98
specific to sand dunes. Site 3 (Coordinates: E - 312676 / N - 5171820) is located on the Wahluke Unit near
the White Bluffs Ferry landing. The vegetation in this area is primarily Russian knapweed and other
introduced species.
Each series of pitfall traps was laid out along a linear transect. Specimens were collected on a weekly basis
for one year. Samples were removed to the laboratory in Pullman, sorted, prepared, and when identified,
recorded in the appropriate taxonomic database. These databases are included in Zack et al. (2003).
Databases contain identifications, site location, and dates of collection for the period April 2002–April 2003.
All specimens thus far identified are recorded.
Light trapping for moths and other light-attracted insects was also initiated in April 2002. Both a mercury
vapor system, which involves active collecting, and a series of black light traps, where the light is placed over
a bucket and allowed to capture insects throughout the night, were used. Contents of black light traps were
collected the following morning.
Light trapping was conducted at 15 sites that were monitored every 2–3 weeks from April 2002 to April 2003.
Sites were concentrated in three habitat types: the Wahluke sand dunes, intact shrub-steppe areas, and riparian
zones (especially wooded riparian zones) along the Wahluke irrigation system and associated impoundments.
Species level identification of arthropods can be a long, slow process that often depends ultimately on sending
specimens off to recognized experts in particular taxonomic groups. Thousands of specimens are still awaiting
identification from the 1994–2000 studies. However, because of the amount of baseline data for the Hanford
Site that has been accumulated over the last decade, and because of the presence of authoritatively identified
voucher material that is now in entomological collections at Washington State University in Pullman, it is
now possible to identify many specimens without sending them off to outside experts. This is evident in the
number of species identified in the beetle and moth databases for 2002–2003.
Results and Discussion
This study collected and processed approximately 12,000 specimens of terrestrial invertebrates.
Approximately 50–60% of the insects collected have been identified to date. To date, 376 species have been
identified (Table 9.1), the majority coming from the Lepidoptera (moths) and Coleoptera (beetles). Numerous
species not previously collected at Hanford, especially in the orders Trichoptera (caddisflies) and Lepidoptera
(moths), have been added to the invertebrate fauna of the Hanford Site. Approximately 200–300 species are
still awaiting identification. Most of these specimens are in the hands of taxonomic experts. Groups with the
highest percentages of unidentified specimens include moths and beetles while identifications for groups such
as fleas and earwigs are complete.
The results presented in this report should be considered preliminary due to the numerous species still
awaiting identification; it is likely that it is from these specimens that the most significant finds will be made.
At the time of the publication of Soll et al. (1999), 1,536 species of terrestrial arthropods had been identified.
Since that time, another 143 species have been positively identified, making a total of 1,679 species. These
additions include species identified after 1999 and those thus far identified from the 2002–2003 study.
Approximately 200–300 taxa from these collections still await identification. These latter taxa are ones for
which we have not been able to find competent taxonomists or groups for which taxonomists do not exist.
Although no species new to science have been added from our 2002–2003 study as yet, three new species
have been identified from previous collections since Soll et al. (1999) for a total of 46 from Hanford studies
over the last decade (Table 9.2). The three new species include a scarab beetle (Aphodius sp.), a snow
scorpionfly (Boreus sp.), and a parasitic wasp, Macrocentrus shawi Ahlstrom. New state records are
sometimes difficult to ascertain because of the lack of catalogs and checklists; however, the number of species
new to Washington state is estimated between 150–200.

9. TERRESTRIAL INVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
99
Table 9.1. Number of species level identifications of terrestrial invertebrates, 2002–2003 study.
Class Order
Number of
Species
Identified
Approximate Number of
Species Remaining to
Be Identified
Malacostraca Isopoda (sowbugs) 1 0
Arachnida Araneae (spiders) 050-100
Scorpiones (scorpions) 1 0
Solifugae (sun spiders) 2 2
Diplopoda (millipedes) 2 2
Chilopoda (centipedes) 2 1
Insecta (insects) Coleoptera (beetles) 78 50-75
Dermaptera (earwigs) 1 0
Hemiptera (true bugs) 310-20
Hymenoptera (bees, wasps, and ants) 12 30-40
Lepidoptera (moths and butterflies) 236 50-75
Orthoptera (crickets and grasshoppers) 22-3
Siphonaptera (fleas) 2 0
Trichoptera (caddisflies) 34 0
TOTAL TAXA 376 197-318
TREATMENTS OF INDIVIDUAL ORDERS
Order Isopoda – Sowbugs
A single species of sowbug occurs at one pitfall site near the White Bluffs Ferry landing. Sowbugs are
omnivores in their feeding habitats and like relatively moist soils higher in organic content. This is the only
site on the Monument where sowbugs have been collected, although they are probably common in similar
environments.
Order Araneae – Spiders
Over 150 pit trap samples of spiders have been collected in the course of the 2002–2003 study alone,
representing between 1,500 and 2,000 specimens. A portion of these (approximately 1,000 specimens) is
currently in the hands of a taxonomic specialist, but results are still forthcoming. The identification of spiders
should add significant information to our findings relative to both the biodiversity and the ecology of
terrestrial arthropods on the Hanford Site.
Order Scorpiones – Scorpions
A single species of scorpion, Paruroctonus boreus (Girard), is found on the Hanford Site and throughout
Eastern Washington. The species is common in shrub-steppe environments, especially those in which
cheatgrass is not a significant portion of the ground cover (Zack and Looney, in prep.). As a large predator,
the scorpion may have difficulty navigating through dense cheatgrass; alternatively, factors such as soil
structure and moisture may limit scorpions to drier, sandier sites.

9. TERRESTRIAL INVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
100
Table 9.2. Arthropod taxa new to science collected at Hanford, 1994–2003.
Order Family Genus and Species
Taxa New to
Science
Coleoptera (Beetles) Scarabaeidae Aphodius sp. 1
Aphodius sp. 2
Glaresis sp.
3
Diptera (True flies) Anthomyiidae Paradelia sp. 1
Asilidae Efferia sp. 1
Efferia sp. 2
2
Dolichopodidae Asyndetus sp.
Sympycnus sp.
Thrypticus sp.
3
Sarcophagidae Blaesoxipha sp.
Eumacronychia sp.
Senotainia sp.
3
Homoptera (Leafhoppers) Cicadellidae Auridius ordinatus crocatus Hamilton
Aceratagallia compressa Hamilton
Aceratagallia zacki Hamilton
Ceratagallia vipera Hamilton
4
Hymenoptera (Bees, Wasps, and
Ants)
Andrenidae Andrena sp.
Perdita sp.
2
Braconidae Macrocentrus shawi Ahlstrom 1
Colletidae Colletes sp. 1
Megachilidae Osmia sp. 1
Osmia sp. 2
2
Perilampidae Perilampus sp. 1
Lepidoptera (Moths) Coleophoridae Coleophora spp. 1-12 12
Noctuidae Copablepharon sp. 1
Copablepharon sp. 2
Oncocnemis parvacana Troubridge
and Crabo
Protogygia sp.
Spaelotis bivaca Lafontaine
5
Scythrididae Arenoscythris sp. 1
Arenoscythris sp. 2
Asymmetrura sp.
Neoscythris sp.
4
Mecoptera (Scorpionflies) Boreidae Boreus sp. 1
Solifugae (Sun Spiders) ? ? 1
TOTAL 46

9. TERRESTRIAL INVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
101
Order Solifugae – Sun Spiders
Sun spiders are an unusual group of predatory arthropods that have very painful bites but no toxic effects.
They are not commonly collected, and their distributions, especially in Washington state, are in need of study.
Their taxonomy is not well understood. Only adult males (rarely females through association) can be
identified to species. This can complicate efforts at identification, as most collections consist largely of
immatures and females. Until recently, two species of sun spider had been identified from Hanford. Both of
these species are listed as species of concern in British Columbia (LTABC 2002), but their distribution and
abundance in Washington state is virtually unknown. A third species of sun spider from previous Hanford
collections has recently been identified as new to science and is currently being described (J. Brookhart pers.
comm.).
Order Dermaptera – Earwigs
There is a single species of earwig, Forficula auricularia L., at Hanford and throughout the central basin of
Washington. This introduced species is widespread throughout the United States and Canada. The species can
be common in pitfall traps, and records were maintained in order to obtain habitat and season information.
Our findings indicate that earwigs are more common in moist and disturbed areas. Moisture probably limits
its distribution on the Hanford Site.
Order Orthoptera – Grasshoppers and Relatives
Little attempt was made to document grasshoppers, crickets, and relatives. One of the ground crickets—
Stenopelmatus fuscus Haldeman—was commonly taken in the pit traps and phenological information was
kept for this species.
Order Hemiptera – True Bugs
Permanent irrigation waters, especially canals with naturalistic channels and shorelines, have significant
numbers of aquatic bugs. Only limited resources were applied to this order during the current study, although
many as yet unidentified adult specimens were collected during light trapping. A sampling objective was to
locate specimens, via aquatic sampling, of a naucorid bug (creeping water bug) that was recorded from a pond
on central Hanford (Emery and McShane 1978). The closest area from which this bug is known is extreme
southern Idaho. Knowledge of this group indicates that if the insect does occur at Hanford, the irrigation
canals would be the best place to look. However, we conducted an intensive search for the bug and did not
find it. Previous Hanford records may be in error, as those authors are known to have misidentified a number
of insect taxa. No voucher material is available to confirm the earlier reports.
Order Trichoptera – Caddiflies
Caddisflies are a group of insects with aquatic larvae and moth-like adults. Adults are collected at light traps,
and it is impossible to know from what aquatic source they derive. At least 34 species have been collected
from light traps along the Columbia River and the Wahluke irrigation channels. Thirteen of the taxa were
species not collected by Newell et al. (2001) at Rattlesnake and Snively Springs on the ALE Reserve. Six or
seven of these species may represent new records for the state of Washington, but this conjecture needs to be
verified by a search of the literature. Interestingly, 9 of the 26 species collected by Newell et al. (2001) were
not represented in the collections from the current study. It is possible that these species occur solely in
association with spring systems.
Order Lepidoptera – Moths and Butterflies
Over 200 species of moths have already been identified by this study, with another 50–75 species awaiting
identification. Based on identifications so far, the moth fauna of the Wahluke and Saddle Mountain regions
appears to be roughly comparable to that found from 1994–2000. The number of species collected and
identified is somewhat smaller than that during previous studies but that is probably an artifact of less
collection time and fewer habitats surveyed. A greater number of moths that are associated with trees and

9. TERRESTRIAL INVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
102
riparian areas have been found by the current study, as these habitats are more common on the North Slope.
Several of the new species of Coleophora (Coleophoridae) discovered in previous Hanford studies were again
found during this project. Several groups of moths such as pyralids, geometrids, and micromoths will be sent
to taxonomic experts in the very near future.
The collection and identification of moths can provide significant information regarding land use and
disturbance as these insects often are closely associated to specific host plants as larvae. As host plant
availability changes throughout the season, so will the appearance and abundance of certain species. In order
to take full advantage of the potential of moths as indicator species, it is important to conduct monitoring
throughout the complete season. Additionally, it can be important to study a fauna for several seasons due to
the physical and climactic events that affect plant occurrence and abundance.
Considerable time and effort was spent surveying the moth fauna of the dunes on central Hanford (1994–
2000) and in the Wahluke Wildlife area (2002–2003). At least four species new to science have been
discovered on the dunes, including species of Arenoscythris (Scythrididae) and Copablepharon (Noctuidae).
Because of the extensive moth collecting conducted on ALE and central Hanford from 1994–2000, the
discovery of many species new to science or new state records was not expected during the 2002–2003 study.
Still, two significant finds were discovered. One is a new species of Arenoscythris (Scythrididae) from the
Wahluke sand dunes. This discovery is very noteworthy in light of the new species of Arenoscythris moth
previously found on the central Hanford dunes. Although capable of flight, these moths fly only a few inches
over the substrate. The finding of distinct species in these two areas may be an indication of the ecological
separation of these dunes systems for an extended period of time and suggests that further surveys of the
dunes may yield more species of interest.
Another noctuid moth, Protogygia comstocki (Noctuidae) was also collected in the Wahluke dunes. This
species had not been collected in Washington since the 1950s. These specimens may represent one of the few
remaining populations in Washington. These findings are significant when one considers that other sand dune
habitats in central Washington have been extensively surveyed for noctuid moths without finding these taxa.
More extensive sampling for other taxonomic groups in sand dune habitats off of the Hanford Site is likely to
further underscore the unique importance of these habitats at Hanford.
Numerous moth species not previously collected on ALE or Central Hanford were collected, especially in
wooded riparian areas adjacent to irrigation runoff streams or ponds. For the most part these are common
species that would be found in this type of riparian zone habitat throughout Eastern Washington. This type of
habitat, however, is rare on the ALE Reserve and on Central Hanford.
The two new species of Copablepharon (Lepidoptera: Noctuidae) are being described by Crabo (in prep.) in
the Moths of America North of Mexico series in a fascicle to be published in late 2004.
In previous management recommendations (Soll et al. 1999) it was stated that we should try to retain
populations of milkweed on the North Slope. Milkweed is the primary food source for monarch butterfly
larvae, the Northwest populations of which have been declining recently. Milkweed is very common along the
irrigation canals and ponds on the Saddle Mountain Unit . Even though we searched milkweed throughout the
season, we never encountered the larvae of monarch butterfly. Although these areas appear to be perfect for
larval development, it may be that they have not yet been “discovered” by adults—the number of monarchs
may be a low point in long-term population cycles.
Order Coleoptera – Beetles
During the current study, beetles were taken primarily through pit trapping. The primary foci were ground
beetles (Carabidae) and darkling beetles (Tenebrionidae). The species richness of these groups was lower than
that encountered during previous Hanford studies, but that was to be expected due to the significantly smaller
number of habitats sampled and the single year of sampling during the current study. One darkling beetle not
found in previous studies was discovered in pit traps located at the White Bluffs Ferry site; this taxon is still
awaiting identification. Additionally, a single specimen of the ground beetle, Pseudaptinus tenuicollis, was

9. TERRESTRIAL INVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
103
also discovered at the Ferry site location. The finding of this beetle represents a significant range extension
from its nearest locality in southern Idaho. Nothing is known of this species’ distribution or habitat
preferences in Washington. The rare beetle Cononotus lanchesteri (Zack and Looney 2001) was consistently
collected at one of the pit trap sites. This beetle is known only from Hanford in Washington state but appears
to be somewhat widely distributed across the Site.
Order Hymenoptera – Bees, Wasps, and Ants
The primary concentration in this order was the collection of diversity and phenological data on ants and bees.
Ant collections have been submitted to a taxonomic authority. No significant findings are expected from a
rarity standpoint. The bee specimens are still being processed and will be submitted to taxonomic
collaborators in the near future.
When one collects in Eastern Washington off of the Hanford Site, one of the most commonly encountered
species of bee is the honeybee, a domesticated introduced species. Honeybees were collected very rarely on
the Site during both the 1994–2000 and 2002–2003 studies while numerous species of wild bees were
common. This may be due to the predominance of native vegetation on the Hanford Site, as well as its
distance from urban or agricultural areas where honeybees are most common.
Conclusions
The diverse insect fauna of the Hanford Site was one of the resources called out in the Presidential
Proclamation establishing the Hanford Reach National Monument in June 2000 (Presidential Proclamation
7319). Insects not only are important as organisms of biological study, but they also have economic
importance as pests and beneficials. Entomological studies of the site continue to indicate that Hanford is
unusual in its lack of pest species and in its abundance of native taxa. Agricultural pest species such as corn
earworm, alfalfa looper, celery looper, and numerous cutworms make up the bulk of trap samples outside of
the Hanford Site. These taxa are collected only in small numbers at Hanford. At the same time, the native
arthropod fauna of the Hanford Site provides one of the few remaining areas where potentially beneficial
native insects may be sought and, perhaps, found.
Shrub-steppe habitat has a relatively distinctive arthropod fauna, which appears to vary with the amount of
disturbance and degradation within the habitat. Based on invertebrate collections thus far, it appears that
shrub-steppe habitats in the Wahluke and Saddle Mountain Units are more degraded than that of the ALE
Reserve. Several arthropod species that were encountered in habitats south and west of the Columbia River
(e.g., snow scorpionflies [Mecoptera: Boreidae] and a winter scarab [Aphodius new species – Coleoptera:
Scarabaeidae]) were not found on the North Slope. The species richness of ground dwelling beetles is also
less in the Wahluke and Saddle Mountain areas. It is not possible to say at this time whether these areas
exhibit greater or lesser overall diversity than Central Hanford and the ALE Reserve because of differences in
the extent of sampling between the surveys of the 1990s and the present study, as well as the number of
species remaining to be identified (especially in the non-noctuid moths). It must be noted that invertebrate
collections on the ALE Reserve were made prior to the 2000 wildfire that swept the Reserve and severely
altered some shrub-steppe habitats (Evans et al. 2002). Fire has been associated with reductions in total
invertebrate family richness as well as in total taxa richness of predatory, detritus-feeding, and ground
dwelling invertebrates in shrub-steppe environments at Hanford (Karr 2000). The reliability of certain
invertebrate taxa as indicators of habitat condition merits further study.
The Hanford Site likely represents the closest approximation to a pre-European colonization insect fauna as
can be found in Eastern Washington. The unique character of the Hanford fauna is likely associated with the
predominance of native vegetation and other natural habitat characteristics. For example, wild bees are the
most commonly encountered Hymenopterans on the Hanford Site, an indication of the predominance of
native vegetation on the site. In the surrounding urban and agricultural landscape, the introduced domesticated
honeybee is most common. Several groups of insects appear to be associated with areas of extensive
microbiotic soil crusts. The mite and Collembola (springtail) fauna represented significant portions of pit fall

9. TERRESTRIAL INVERTEBRATES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
104
samples where the crust was intact and were virtually nonexistent in samples where the crust had been
destroyed. The distribution of snow scorpionflies (Boreus: Mecoptera: Boreidae) exhibits the same contrast:
The larvae of these small insects feed on moss and are not found in areas where the crust has been degraded
or destroyed. During our 1994–2000 sampling, we collected four species of Boreus on ALE—one of which is
a species new to science. This is the only site known to the world authority on this taxonomic group from
which four species have been recorded (N. Penny pers. comm.)!
The sand dune habitats of Central Hanford and the Wahluke Slope exhibit an invertebrate fauna distinct from
other areas of the Site. Based on collections of dune habitats throughout the state, it appears that a number of
these dune taxa are also limited outside the Hanford Site due to isolation of habitats and, perhaps, habitat
degradation and conversion.
Despite extensive and fruitful entomological diversity studies, we still know very little concerning the
arthropod fauna of the Hanford Site. Species new to Washington state and new to science continue to be
found. Such discoveries are likely to continue and accelerate if longer-term studies can be conducted,
especially if surveys are focused on lesser-studied taxa. Large numbers of specimens in some of the lesser
known groups (e.g., spiders) have been collected and processed, and it is hoped that the identification and
evaluation of these organisms will add significantly to our understanding of the biological diversity of the
Hanford Site.
Recommendations
• Areas of the Hanford Reach National Monument and Central Hanford should be considered for long-
term entomological diversity studies. The collection and preparation of insects is a very time-
intensive activity; the tremendous number of species within any large system, their varied habits, and
methods of collection make it impossible to obtain a true indication of the breadth of species diversity
unless a multiyear study is conducted. Survey work for moths in particular should be continued.
Survey work in riparian zones is needed, as is further work on the sand dunes. The sand dunes have
an extensive and distinct fauna, especially of moths, and should be the subject of weekly to biweekly
collecting for at least one to several full years. A number of species new to science as well as several
rarely collected species have already been collected from these habitats, and more taxa of
biogeographic significance are likely to be found.
• A series of pitfall traps was established near the White Bluffs Ferry landing. This is a disturbed area
with some introduced vegetation but also is more naturally riparian being along the Columbia River.
Perhaps because of this it has a distinct fauna not found in general shrub-steppe. Access to less
modified sites (especially those along the River) is limited and boat access is difficult, but some of
these areas should be sampled.
• This study did not survey in riparian areas associated with the extensive irrigation wasteway system
in the Wahluke and Saddle Mountain Units. There may be a distinct fauna associated with these areas
that should be examined.The sand dune habitats of the Hanford Reach National Monument support a
distinctive fauna of moth species found nowhere else on the Hanford Site , including a number of
species that are regionally rare. These dunes represent a high-quality habitat that is increasingly rare
in Washington state. Shrub-steppe habitats with intact biological soil crusts also support a distinctive
invertebrate fauna. Management should aim to minimize disturbance to both these critical habitat
types and to maintain them in as natural a state as possible.
• The Monument maintains an active invasive plant species control program that includes the use of
chemical herbicides to control selected noxious weeds. The collecting site near the White Bluffs Ferry
was relatively disturbed and may be a candidate area for the use of herbicides. While the site does
appear to have a different ground beetle fauna than other sample sites, most of this fauna is common
to disturbed areas throughout the Hanford Site and should not be considered at risk from chemical
spray.

Invasive Plant Species

BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
107
10. Invasive Plant Species Inventory of the Hanford Reach
National Monument: 2002–2003
James R. Evans, John J. Nugent, and Jennifer K. Meisel
Introduction
Invasive plant species are one of the greatest threats to the biodiversity of the Hanford Site (Soll et al. 1999).
In order to assess the current status of invasive plant species on the Hanford Reach National Monument, an
inventory of noxious weeds in Monument management areas was conducted by personnel from The Nature
Conservancy’s Washington Field Office and staff of the Hanford Reach National Monument in 2002 and
2003 (Evans et al. 2003).
Methods
A preliminary target list of actual and potential invasive plant species for the Monument (Table 10.1) was
developed during winter 2002 after consulting ecological literature (TNC 2002, Sackschewsky and Downs
2001, CNAP 2000, Mitchell 2000, Mullins et al. 2000, PNEPPC 1997) and Washington state weed law
(NWCB 2003a), and following discussions with staff of the Hanford Reach National Monument, personnel
from the Hanford Biological Control Program, and local professionals. Species selected for inventory
(hereafter referred to as “target species”) were those which met the following criteria: 1) a demonstrated
ability to outcompete native plant species and to change the structure and/or function of natural ecosystems in
the Columbia Basin and/or elsewhere in the arid and semiarid West, and 2), ranges that currently include the
Lower Columbia Basin or nearby areas or which can reasonably be expected to migrate into the Columbia
Basin within the relatively near future. This working list of target weeds is intended to be a flexible tool that
can be expanded or reduced as new information about plant migrations and ecological effects becomes
available.
The noxious weed list is divided into upland and riparian habitat types. Species that may occur in either
habitat type were placed into the type where they were most likely to be encountered, but surveys for that
species were not necessarily limited to that habitat type. The list of species for each habitat type is further
divided into species that have been confirmed to occur on Monument lands (Active List) and species which
have not yet been documented on Monument lands (Watch List). An additional category identifies invasive
plant species that display considerable ecological impacts on infested lands, but which are already so
widespread on the Monument that control is feasible only in selected areas for particular management
purposes (Table 10.1c). Since they are already ubiquitous throughout all or most of their suitable habitats,
these widespread species of concern were not inventoried during the surveys.
Noxious weed surveys were performed between April 1 and October 10, 2002, and between April 15 and July
1, 2003. Geographic locations of invasive species occurrences were recorded as either points, lines, or
polygons using portable GPS units. For each occurrence, the following additional information was also
documented:
• Species name
• Infestation size (length x width)
(Continued)

10. INVASIVE PLANT SPECIES INVENTORY OF THE HANFORD REACH NATIONAL MONUMENT: 2002–2003
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
108
Table 10.1. Target list of invasive plant species for the Hanford Reach National Monument. a) Species that
occur primarily in uplands; b) species that occur primarily in wetlands and riparian areas; c) species of
concern that are already widespread. Scientific names are from Kartesz and Meacham (1999). Boldface
indicates nomenclatural changes since Hitchcock and Cronquist (1973). Column 4 indicates weed regulatory
status in Washington state, including Monitor (M) and species not listed (NL) by the Washington State
Noxious Weed Control Board (NWCB 2003a).
a. Upland Species: Active List
Scientific Name Hitchcock & Cronquist (1973) Common Name Weed Class
Acroptilon repens Centaurea repens Russian knapweed B
Alhagi maurorum No record camelthorn B
Bassia scoparia Kochia scoparia kochia B
Cardaria draba Cardaria draba white top C
Centaurea diffusa Centaurea diffusa diffuse knapweed B
Centaurea solstitialis Centaurea solstitialis yellow starthistle B
Chondrilla juncea No record rush skeletonweed B
Cirsium arvense Cirsium arvense Canada thistle C
Cirsium vulgare Cirsium vulgare bull thistle C
Convolvulus arvensis Convolvulus arvensis field bindweed C
Gypsophila paniculata Gypsophila paniculata baby’s breath C
Lepidium latifolium Lepidium latifolium perennial pepperweed B
Linaria dalmatica Linaria dalmatica dalmatian toadflax B
Onopordum acanthium Onopordum acanthium Scotch thistle B
Secale cereale Secale cereale winter rye C
Sphaerophysa salsula No record swainsonpea B
Tribulus terrestris Tribulus terrestris puncturevine B
Upland Species: Watch List
Scientific Name Hitchcock & Cronquist (1973) Common Name Weed Class
Abutilon theophrasti No record velvetleaf A
Anthriscus sylvestris No record wild chervil B
Carduus nutans Carduus nutans musk thistle B
Cenchrus longispinus Cenchrus longispinus sandbur B
Centaurea biebersteinii Centaurea maculosa spotted knapweed B
Euphorbia esula Euphorbia esula leafy spurge B
Sorghum halepense Sorghum halepense johnsongrass A
Taeniatherum caput-medusae Elymus caput-medusae medusahead wildrye NL

10. INVASIVE PLANT SPECIES INVENTORY OF THE HANFORD REACH NATIONAL MONUMENT: 2002–2003
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
109
b. Wetland and Riparian Species: Active List
Scientific Name Hitchcock & Cronquist (1973) Common Name Weed Class
Eleagnus angustifolia Eleagnus angustifolia Russian olive NL
Lythrum salicaria Lythrum salicaria purple loosestrife B
Myriophyllum spicatum Myriophyllum spicatum Eurasian watermilfoil B
Phragmites australis Phragmites communis common reed C
Sonchus arvensis ssp. arvensis Sonchus arvensis ssp. arvensis perrennial sowthistle B
Tamarix parviflora Tamarix parviflora saltcedar, tamarisk NL
Tamarix ramosissima No record saltcedar, tamarisk B
Wetland and Riparian Species: Watch List
Scientific Name Hitchcock & Cronquist (1973) Common Name Weed Class
Amorpha fruticosa No record indigobush B
Cyperus esculentus Cyperus esculentus yellow nutsedge B
Epilobium hirsutum No record hairy willow-herb M
Myriophyllum aquaticum Myriophyllum brasiliense parrotfeather B
c. Species of concern that are already widely established.
Scientific Name Hitchcock & Cronquist (1973) Common Name Weed Class
UPLAND
Bromus tectorum Bromus tectorum cheatgrass, downy brome NL
Salsola tragus Salsola kali Russian thistle, tumbleweed NL
WETLAND AND RIPARIAN
Phalaris arundinacea Phalaris arundinacea reed canarygrass C
• Cover class (< 1%, 1-10%, 11-25%, 26-50%, 51-100%)
• Management Unit
• County
• USGS 7.5′ quadrangle
• Location information
• Disturbance type, if known
• Associated vegetation
All GPS coordinates were imported into GIS layers (UTM NAD27). Weed occurrences were also drawn on
USGS 7.5′ topographic maps. Some large polygons in degraded, low-quality areas were recorded only on
topographic maps, which were digitized later. A few large polygons were approximated from existing
vegetation maps (Secale cereale), from aerial imagery (Eleagnus angustifolia), or from direct expert accounts
(Myriophyllum spicatum).

10. INVASIVE PLANT SPECIES INVENTORY OF THE HANFORD REACH NATIONAL MONUMENT: 2002–2003
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
110
INVENTORY SEARCH STRATEGIES
Inventory staff searched over 20,000 acres (8097 ha) of the Monument for targeted invasive plant species
(Fig. 10.1). Inventories focused on areas where noxious weeds have been previously reported, on special
habitats (e.g., springs or riparian areas) where certain target species were expected to occur, and in disturbed
lands and corridors. Most non-native plant species establish most readily in areas such as roadsides, gravel
pits, abandoned agricultural fields, and other disturbed lands. Roads and watercourses, in particular, can
function as corridors for weed transport and migration into new areas. Detection of weeds along corridors
prompted systematic searches of surrounding areas. Searches of the target areas such as these have a high
likelihood of turning up many noxious weed occurrences (Zamora and Thill, 1999). Some noxious weed
species are highly mobile and capable of establishing in undisturbed habitats, necessitating systematic
overland searches. Such overland searches were limited by time constraints for this inventory but were
conducted in areas of particular biological importance such as Umtanum Ridge on the McGee Ranch–
Riverlands Unit, the White Bluffs, and portions of the Arid Lands Ecology (ALE) Reserve. Inventory staff
also searched for noxious weeds while traversing expansive areas of the ALE Reserve in the course of a
concurrent vegetation-monitoring project.
The inventory was conducted primarily on shrub-steppe uplands and natural springs. Aquatic environments
associated with irrigation wasteways and artificial impoundments on the North Slope were not included in the
survey. Riparian habitats surrounding these features were only partially surveyed, and invasive species
associated with these habitats are undoubtedly substantially underreported here. Aquatic and shoreline
habitats of the Columbia River were surveyed on five different days during July and October 2002 and July
2003 and were undoubtedly undersampled. Hydrophytic weeds and other invasive species that occur between
the high- and low-water marks of the river appeared to be widespread to ubiquitous along the length of the
river shore and were not mapped.
Results and Discussion
Noxious weed surveys in 2002 and 2003 confirmed the presence of 23 invasive plant species on the Hanford
Reach National Monument (Table 10.1), including three species that had not previously been documented on
Monument lands. Overall, the inventory recorded 401 occurrences of invasive species, infesting more than
9000 acres (> 3600 ha) over all management units of the Monument (Table 10.2, Fig. 10.2).
Diffuse knapweed (Centaurea diffusa) infested more than 3600 acres (>1400 ha), more than 40% of the total
area occupied by target invasive plant species on the Monument. Diffuse knapweed infestations were
common along roads but also occurred in riparian areas, in old fields, and, most noteworthy, in some
shrublands. Diffuse knapweed appears to be ubiquitous along the shoreline of the Hanford Reach between the
high- and low-water marks. This acreage has not been mapped or included in area figures, so that the total
acreage of diffuse knapweed infestations reported here are clearly underestimates.
Clonal colonies of Russian knapweed (Acroptilon repens; 943 acres/381 ha) and whitetop (Cardaria draba)
dominated considerable acreage in riparian areas, former agricultural lands, and other disturbed areas.
Whitetop (63 occurrences, 497 acres) in particular was present at nearly every spring, seep, well, or other area
where soil moisture may have been closer to the surface than in the surrounding landscape.
Rush skeletonweed (Chondrilla juncea; 692 acres/280 ha) and yellow starthistle (Centaurea solstitialis; 312
acres/126 ha) both formed large patches in highly disturbed areas. However, these highly mobile species
appeared in lightly to moderately disturbed grasslands and shrublands as well. New occurrences documented
by USFWS personnel during spring 2003 indicate that infestations of both of these composite species have
been underestimated by this inventory.

10. INVASIVE PLANT SPECIES INVENTORY OF THE HANFORD REACH NATIONAL MONUMENT: 2002–2003
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
111
Fig. 10.1. Search areas for invasive plant species, Hanford Reach National Monument, 2002–2003.

10. INVASIVE PLANT SPECIES INVENTORY OF THE HANFORD REACH NATIONAL MONUMENT: 2002–2003
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
112

10. INVASIVE PLANT SPECIES INVENTORY OF THE HANFORD REACH NATIONAL MONUMENT: 2002–2003
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
113
Fig. 10.2. Areas infested by invasive plant species, Hanford Reach National Monument, 2002–2003.

10. INVASIVE PLANT SPECIES INVENTORY OF THE HANFORD REACH NATIONAL MONUMENT: 2002–2003
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
114

10. INVASIVE PLANT SPECIES INVENTORY OF THE HANFORD REACH NATIONAL MONUMENT: 2002–2003
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
115
Saltcedar (Tamarix spp.; 1284 acres/520 ha) was the second most common species in the inventory,
comprising more than 14% of the total area occupied by target invasive plant species. Saltcedar was common
on seeps along the face of the White Bluffs as well as along irrigation wasteways and impoundments, where it
was often codominant with Russian olive (Eleagnus angustifolia; 579 acres/234 ha). With the exception of
these woody species, the invasive species of the artificial wetlands and riparian areas associated with
wasteway impoundments were considered low priorities for inventory purposes. Species such as purple
loosestrife (Lythrum salicaria) and common reed (Phragmites australis) were consequently undersampled
during this inventory, and the results presented here are poor indicators of these species’ abundance on the
Monument. Three invasive plant species were documented for the first time on the Hanford Reach National
Monument. A single individual of dalmatian toadflax (Linaria dalmatica) was observed along the west side of
the White Bluffs Road in the Wahluke Unit. Several individuals of Scotch thistle (Onopordum acanthium)
were recorded at the mouth of an abandoned quarry on the ALE Reserve. Perennial sowthistle was observed
in some abundance in a riparian area that is associated with the WB 10 Ponds on the Wahluke Unit. This
species may have been present in this area for some time without notice.
Table 10.2. Occurrences and areas infested by target invasive plant species, Hanford Reach National
Monument 2002–2003.
Common Name Scientific Name
Total
Occurrences
Area
(hectares)
Area
(acres)
Russian knapweed Acroptilon repens 48 381.6 943.1
camelthorn Alhagi maurorum 1< 0.1 < 0.1
whitetop Cardaria draba 63 201.2 497.0
diffuse knapweed Centaurea diffusa 88 1488.9 3679.1
yellow starthistle Centaurea solstitialis 29 126.5 312.7
rush skeletonweed Chondrilla juncea 31 280.0 692.0
Canada thistle Cirsium arvense 24 6.1 15.1
bull thistle Cirsium vulgare 3< 0.1 < 0.1
field bindweed Convolvulus arvensis 29 33.7 83.3
Russian olive Eleagnus angustifolia 8234.3 579.0
baby’s breath Gypsophila paniculata 1< 0.1 < 0.1
kochia Kochia scoparia 817.3 42.7
perennial pepperweed Lepidium latifolium 13 122.7 303.1
dalmatian toadflax Linaria dalmatica 2< 0.1 < 0.1
purple loosestrife Lythrum salicaria 30.8 2.0
Eurasian watermilfoil Myriophyllum spicatum 29.4 23.1
Scotch thistle Onopordum acanthium 30.1 0.2
common reed Phragmites australis 11 36.1 89.3
winter rye Secale cereale 3192.6 475.8
perennial sowthistle Sonchus arvensis 1Area Unknown
swainsonpea Sphaerophysa salsula 10 15.0 37.10
saltcedar Tamarix ramosissima,
T. Parviflora
19 519.5 1283.8740.3
puncturevine, tackweed Tribulus terrestris 10.1 0.2
TOTALS 401 3665.8 9058.67755.

10. INVASIVE PLANT SPECIES INVENTORY OF THE HANFORD REACH NATIONAL MONUMENT: 2002–2003
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
116
CHARACTERIZATION OF INFESTATIONS OF TARGET SPECIES BY MANAGEMENT AREA
The Fitzner-Eberhardt Arid Lands Ecology (ALE) Reserve. While ALE contains many of the highest
quality native plant communities on the Monument, invasive species are a mounting concern. Riparian
vegetation at important spring systems (Rattlesnake, Snively, and Benson/Bobcat) is highly degraded and
increasingly dominated by invasive species such as Russian knapweed, whitetop, and Canada thistle.
Whitetop is common also at many seeps along the middle slopes of the Rattlesnake Hills. Russian knapweed
and whitetop are common and probably spreading in highly disturbed lands along the length of Cold Creek.
Diffuse knapweed is widespread along many of the Reserve’s roadways, including those at higher elevations
and in remote locations, and in the dry creekbed of upper Cold Creek, but has not yet been documented in
surrounding natural areas. Rush skeletonweed is established in the lower Cold Creek Valley and has recently
appeared in lightly to moderately disturbed lands in Iowa Flats and other areas on the low slopes of
Rattlesnake Mountain. The unit’s recent fire history has favored the increase and spread of many of these
invasive species, along with cheatgrass (Bromus tectorum) and Russian thistle (Salsola tragus).
The McGee Ranch–Riverlands Unit. Compared to ALE, this is an extremely weedy area. Diffuse
knapweed, Russian knapweed, whitetop, perennial pepperweed (Lepidium latifolium), and other invasive
species infest large areas of the McGee Ranch area north of SR 24. It is notable that diffuse knapweed has
escaped from gravel roads in this area and infested sagebrush shrublands, as well as abandoned agricultural
fields, at the west end of the site. The Riverlands area hosts a number of large infestations of Russian
knapweed, most notably in the vicinity of the Midway townsite and at China Bar. China Bar also hosts the
unit’s only documented occurrence of saltcedar. Fortunately, biologically rich Umtanum Ridge appears to be
largely free of target invasive plant species at this time, except for small infestations of diffuse knapweed and
Russian knapweed on unpaved roads through the area. These isolated occurrences should be high priorities
for treatment.
The Vernita Bridge Recreation Area. Diffuse knapweed, which is common along the Columbia River
shorelines up and down the length of the Hanford Reach, is scattered throughout this unit, particularly on
roadways and in parking and boat launch areas. Two small borrow pits in the eastern section of the site
support riparian vegetation, including Canada thistle and common reed.
Saddle Mountain Unit/Saddle Mountain National Wildlife Refuge. Large areas of this unit between SR 24
and the Columbia River are lightly to heavily infested with noxious weeds. Diffuse knapweed occupies
extensive former agricultural lands in the flats along the shore of the Columbia. Abandoned quarries host
saltcedar, rush skeletonweed, and Russian knapweed. The Saddle Mountain Wasteway and its impoundments,
including Saddle Mountain Lake, host large populations of many riparian weed species, including saltcedar,
Russian olive, common reed, and purple loosestrife.
Wahluke Unit. The riparian areas surrounding the WB 10 Ponds are dominated by Russian olive and host
many other riparian weed species. Saltcedar is abundant in places, particularly along the White Bluffs. Yellow
starthistle is well established in the lowlands and bluffs of the southern portion of this unit, while extensive
patches of Russian knapweed, along with other invasive species, occur in Ringold Flats.
River Corridor Unit. The River Corridor Unit consists of the Hanford Reach and its islands, a one-quarter-
mile buffer along the south and west shores of the river (bordering Central Hanford), and the Hanford Dunes.
The dynamism of the great river, the wide daily fluctuations in riverflow owing to upstream hydroelectric
generation, and a steady supply of riverborne alien propagules make the Columbia River shoreline an
extremely favorable site for colonization by invasive plant species. Hydrophytic weeds such as purple
loosestrife and reed canarygrass (Phalaris arundinacea) are common between the high- and low-water marks
along the length of the Hanford Reach. Diffuse knapweed colonizes this same disturbed elevational zone and
is the most abundant and widespread weed along the river. Large clonal patches of common reed can be
observed upstream from the Wahluke ferry landing. Eurasian watermilfoil (Millefolium spicatum) occurs in
several persistent patches south of the White Bluffs boat launch.

10. INVASIVE PLANT SPECIES INVENTORY OF THE HANFORD REACH NATIONAL MONUMENT: 2002–2003
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
117
Island uplands are subject to infestations similar to mainland uplands with Russian knapweed, diffuse
knapweed, yellow starthistle, rush skeletonweed, and Canada thistle the most widespread and abundant of
invasive species in these areas.
Conclusions
There are more species of noxious weeds infesting larger land areas of the Hanford Reach National
Monument than had previously been documented. While this inventory represents a concerted effort to
provide a detailed picture of the extent of invasive plant species on the Monument, it is far from a complete
picture. Due to inevitable time limitations, large areas of the Monument remain unexplored by inventory
personnel, so that the numbers of species and areas infested that are reported here must be taken as minimum
estimates for invasive plant species on the Monument.
A biological inventory represents only a snapshot in time. Invasive plant populations are dynamic and will
require monitoring annually or more often to accurately apprise management of patterns of abundance and
threats to biological resources. Invasive species that have not yet been recorded on the Monument occur in as
close proximity to its boundaries as in Central Hanford or in the nearby Tri-Cities area (Rice 2002, R. Roos
pers. comm.). In the years ahead, new species of non-native plants will continue to arrive from near and far
(McNeely 2001, Mack et al. 2000).
Managers of the Hanford Reach National Monument will require timely information regarding the
distribution and abundance of invasive plant species in order to adequately protect the biodiversity of the site.
This inventory has documented important information about major noxious weed infestations on the
Monument and helped to lay the groundwork for continuing surveys, which should follow.
Recommendations
Because of the dynamic nature of established invasive plant species populations and the likelihood of further
introductions of non-native species, establishing and maintaining a well-staffed and trained, year-round
invasive species monitoring program in accordance with recommendations in Evans et al. (2003) and Section
11 (this volume) should be a high priority for the Hanford Reach National Monument.
This inventory dealt only with invasive vascular plant species. However, some species of non-native insects,
mollusks, fish, birds, reptiles, amphibians, and mammals are likely to have important impacts on the native
biodiversity of the Hanford Site, now or in the future. Inventories of taxa likely to have deleterious effects
upon conservation targets are strongly recommended.
Herbaceous weeds of artificial riparian areas associated with irrigation wasteway impoundments on the
Wahluke and Saddle Mountain Units were considered low priorities for inventory activities and were, as a
result, considerably undersampled. A more accurate estimate of the abundance and distribution of these
invasive species can only be obtained by a thorough inventory of these areas, should resources permit.
Weed inventory personnel were unable to gain access to the southern portion of the McGee Ranch area
through Gates 121 (from SR 240) and 121B (from Cold Creek County Rd.). Keys to padlocks on these gates
did not work. Hanford Biological Control Program personnel mentioned that their keys to these gates had
stopped working some time ago. Although the area can be accessed via a rough track through sagebrush from
the Umtanum Ridge Rd., this route may not be appropriate for all kinds of transport and may represent a
potential fire hazard during the dry months. Repair or replacement of the Gate 121 and 121B locks would
greatly facilitate inventory and control efforts in this portion of the McGee Ranch–Riverlands Unit.
A gate in sagelands along a powerline access road at the southwest boundary of the McGee Ranch–Riverlands
Unit consists only of loops of barbed wire. This gate, in a remote part of the Monument and near habitats of

10. INVASIVE PLANT SPECIES INVENTORY OF THE HANFORD REACH NATIONAL MONUMENT: 2002–2003
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
118
high biological value, was found open during a survey in 2002. Installation of a standard security gate with
padlock may help to reduce incidences of trespass, which are occasionally reported. Trespassing individuals
or livestock represent an avenue of invasive species introductions that can be controlled by this simple
security measure.
Wide-ranging surveys during 2002–2003 suggest that bull thistle (Cirsium vulgare) is present only as
scattered individuals and does not pose a significant threat to Monument resources. This non-native thistle
may be considered for removal from the priority list of target species. At the same time, dense, persistent
patches of black locust (Robinia pseudo-acacia) at Ringold and elsewhere suggest that monitoring may be
prudent to determine if sexual reproduction is occurring in this potentially invasive species (M. Tu pers.
comm.).

BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
119
11. Invasive Plant Species Management Plan for the Hanford
Reach National Monument
James R. Evans, John J. Nugent, and Jennifer K. Meisel
Introduction
Invasive alien plant species pose one of the most serious threats to the native biodiversity, wildlife habitat,
and scenic values that the Hanford Reach National Monument was created to protect, and for which the entire
Hanford Site is well known (Soll et al. 1999). Managing invasive plant species in a large landscape requires
adequate information about the nature and extent of weed populations, along with careful planning and
judicious use of limited resources in control efforts. The following section describes the main points of a
weed management plan for the Hanford Reach National Monument that is currently being developed by The
Nature Conservancy in cooperation with the U.S. Department of Energy and the U.S. Fish and Wildlife
Service. Full details of the plan are available in Evans et al. (2003).
IMPACTS OF INVASIVE PLANT SPECIES
At Hanford, as elsewhere in western North America, invasive and noxious alien plant species compete against
and reduce habitat available for rare plant taxa and native plant species in general. Invasive species alter
ecosystem strucure and function, disrupt food chains and other characteristics vital to wildlife (including rare
and endangered species) and can dramatically alter key ecosystem processes such as hydrology, productivity,
nutrient cycling, and fire regime.
The deleterious effects of invasive plant species are not limited to natural areas but may also severely impact
local economies. Invasive weeds compete with agricultural crops for light, moisture, and nutrients, clog
irrigation systems, and reduce livestock forage values in pastures and rangelands (Mack et al. 2000, Bridges
1994). Degradation of agricultural lands resulting from invasive species infestations may drastically reduce
land values (TCWPP 2003, Weiser 1997). One local invasive species is even known to puncture bicycle tires.
MANAGEMENT SETTING
Shrub-steppe ecosystems such as that represented on the Hanford Reach National Monument are highly
susceptible to infestation by invasive plant species, especially when disturbed (DiTomaso 2000). The
Monument’s large size (195,000 acres) and the large number of documented or potential invasive plant
species in the area present significant challenges to the stewards of biological resources. Past and present land
use practices such as farming and ranching, military activities, road building and quarrying, and riverflow
management have helped to create conditions favorable for the establishment of many invasive plant species
on Monument lands and throughout the Columbia Basin.
The introduction and spread of invasive plant species is enhanced by the existence of disturbed lands and
corridors (Mack et al. 2000). Potential corridors for the migration of invasive species into and within the
Hanford Reach National Monument include (HRNM 2003):
• Forty-four miles of the Columbia River, including 15 islands.
• Eleven miles of active irrigation canals and wasteways, and more than 1000 acres of associated
impoundments.

11. INVASIVE PLANT SPECIES MANAGEMENT PLAN FOR THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
120
• More than 50 miles of state highway, and more than 180 miles of paved and unpaved secondary roads
in widely varying condition.
• More than 20 miles of powerline corridors and associated access roads.
Certain trends may make invasive species even more of a problem in the future than they are at present. New
weeds may be expected to arrive within the coming years as technology and commerce continue to reduce
barriers to plant migrations (Mack et al. 2000, Mullins et al. 2000). At the same time, recurrent wildfires,
powerline development and maintenance, continued slumping of the White Bluffs, and other disturbances
continually create new habitats for invasive species to colonize.
Management Program Overview
An invasive species control program must be based upon the overall conservation and management goals of
the area for which it is designed. Long-term conservation planning for the Hanford Reach National
Monument is underway; however, the process has not been completed as of this writing. In light of guidance
included in the Presidential Proclamation of June 2000 (Presidential Proclamation 7319), current management
practices, and preliminary results of the Comprehensive Conservation Planning process (USFWS and CBSG
2003, 2002), the following generalizations have been made regarding Monument conservation goals as a basis
for this weed management plan:
• Fully functioning shrub-steppe habitats and the processes that characterize and maintain them,
including their full array of native species.
• Healthy spring and stream habitats with their full complement of associated native vegetation and
wildlife.
• Healthy aquatic and riparian habitats of the Hanford Reach of the Columbia River.
When the final version of a long-term Comprehensive Conservation Plan (CCP) for the Monument is adopted,
weed planning documents should be reviewed to ensure full compatibility with the goals and objectives
outlined in the CCP.
While weed management practices vary, the most successful programs adopt an adaptive, integrated
management approach. The key elements of such an approach are presented in the following sections
(adapted from Tu and Meyers-Rice 2002, DiTomaso 2000, Zamora and Thill 1999, Randall 1996, S. Johnson
pers. comm.).
RESOURCE-BASED MANAGEMENT
Managers should address invasive species issues within the context of Monument conservation goals. A
particular focus on the desired vegetation in place of the invasive weeds at a site rather than on simply
eliminating the weeds themselves is recommended. Restoration of native vegetation is a desirable end goal for
most, but not necessarily all, infested sites. In some cases, non-native species may be used as competitive
plantings or place holders in treatment areas.
PREVENTION
The most effective method of control for invasive plant species is to prevent their establishment. Measures to
minimize the introduction of potentially invasive species onto Monument lands may include administrative
control of access to sites, limitation of access to designated entry points (as along a single, carefully
monitored road), inspection and decontamination of vehicles, cooperative agreements with contractors and
other parties that need regular access to the site, educational programs, and other measures. Different
measures may be applied to different management units or subunits within the Monument, reflecting different

11. INVASIVE PLANT SPECIES MANAGEMENT PLAN FOR THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
121
levels of biological value and condition, and different management goals for particular units. Strong
preventive measures are recommended for the ALE Reserve and for the Umtanum Ridge portions of the
McGee Ranch–Riverlands Unit.
EARLY DETECTION AND SUSTAINED MONITORING
Next to prevention, the most effective method for control of invasive plant species is to detect their presence
early. Existing weed populations are dynamic, and occasional new introductions may be expected even when
rigorous preventive measures are in place. An essential component in successful weed management plans is
provision for extensive and ongoing surveys to detect new occurrences and to monitor existing ones (Snyder-
Conn 2001). An aggressive monitoring program is one of the most cost-effective strategies that can be applied
in weed management. This is critically important in an era where funding for natural resources management is
in decline. Early detection of invasive species occurrences makes it possible for treatment to be applied before
a spot infestation can spread more extensively across the landscape. Timely intervention in turn increases
treatment effectiveness while reducing treatment duration (Belnap and Phillips 2001, Moody and Mack
1988), thus reducing expenditures for staff time and materials and minimizing chemical inputs to the
environment; this in turn reduces the potential for treatment impacts to non-target resources such as native
plants, wildlife, and aquatic resources.
Ongoing monitoring of the status of weed occurrences and the effectiveness of control treatments is also
essential for adaptive management. Documented occurrences of high priority target species (Priorities 1 and
2, described below) must be visited and assessed at least annually. In addition to the precise location of the
infestation, the size and percent aerial cover of the infestation must be recorded. Density measurements (stem
counts) may be the best measure of very small infestations such as the camelthorn infestation in the Wahluke
Unit. All sites (Priorities 1, 2, and 3) that are undergoing active treatment should be assessed at least two
times per year: in the spring, and in the fall following the end of the drought period but before the onset of
dormancy. Some successful programs monitor even more often. A monitoring schedule should be flexible
enough to allow the timing of monitoring visits to fit the phenology of the target species.
To maintain an effective monitoring program, well-trained personnel must be maintained at adequate staffing
levels to carry on this work without serious interruption. While some degree of staff turnover is inevitable in
any position, maintaining continuity of personnel experienced in invasive species monitoring and
management should be a very high priority for the Monument.
PRIORITIZATION OF SPECIES AND SITES
Thirty-six species of invasive weeds have been identified as target species for the Hanford Reach National
Monument weed management program (Section 10, this volume). Twenty-three of these species have been
documented as presently occurring on the Monument. In a large landscape with numerous target weed species
and where infestations vary from a single plant to hundreds of acres or larger in size, a prioritization strategy
for control and elimination of invasive plant species is essential to effectively allocate limited management
resources.
This plan combines species-based criteria with site-based criteria to prioritize specific weed occurrence sites
for treatment. The following factors are among the key criteria considered in the prioritization of sites for
treatment:
• Invasive potential of the weed species.
• Ecological impacts of the weed species on native species and communities (especially in relation to
specific conservation targets),
• The size of the infestation.

11. INVASIVE PLANT SPECIES MANAGEMENT PLAN FOR THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
122
• Proximity of the infestation to valuable biological resources.
• Susceptibility of the invasive species to treatment.
• Potential impacts of treatment upon non-target species.
Invasive species that are fast growing, exhibit high reproductive rates, are highly dispruptive to conservation
targets, occur along pathways of spread, or are otherwise highly mobile on the landscape must be given
priority consideration. High priority is also assigned to small, incipient, isolated or satellite infestations, since
these are the primary loci of population spread and at the same time are the sites where control and
eradication efforts are most likely to be successful (Moody and Mack 1988). Difficulty of control must also
be considered. Infestations where control efforts using available technology and resources are likely to yield
positive results receive higher priority than those where available methods are likely to have little effect.
Target invasive plant species for the Hanford Reach National Monument are divided into an active list of
species documented as occurring on the Monument and a watch list of species not yet documented on the
Monument (Section 10, this volume). Active list species are further divided into groups for prioritization of
treatment activities.
Priority 1 species (Table 11.1a) are perceived as the greatest and most immediate threats to the biological
resources of the Hanford Reach National Monument. Priority 1 species are annual, biennial, and perennial
species that are, in general, prolific seed producers, highly mobile on the landscape, aggressive competitors,
and tenaciously persistent when established.
Table 11.1. Invasive plant species treatment priorities, Hanford Reach National Monument, 2002–2003:
a) Priority 1 species; b) Priority 2 species.
a. Priority 1 Species
Common Name Scientific Name
camelthorn Alhagi maurorum
diffuse knapweed Centaurea diffusa
yellow starthistle Centaurea solstitialis
rush skeletonweed Chondrilla juncea
baby’s breath Gypsophila paniculata
dalmatian toadflax Linaria dalmatica
Scotch thistle Onopordum acanthium
saltcedar Tamarix ramosissimus, T. parviflora
puncturevine Tribulus terrestris
b. Priority 2 Species
Common Name Scientific Name
Russian knapweed Acroptilon repens
whitetop Cardaria draba
Canada thistle Cirsium arvense
Russian olive Eleagnus angustifolia

11. INVASIVE PLANT SPECIES MANAGEMENT PLAN FOR THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
123
The Priority 1 rank includes species such as diffuse knapweed and saltcedar, which are among the most
abundant on the Monument (Section 10, this volume). It also includes several species that are among the least
abundant on the Monument and may, because of the small size of the colonies, be amenable to early
eradication. Ideally, all populations of Priority 1 species should be attacked aggressively with the goals of
eradicating small infestations within a few years and gradually reducing larger infestations. In practical terms,
some infestations of diffuse knapweed and saltcedar in low-quality areas probably cannot be dealt with
effectively without taking critical resources away from areas where high-quality resources must be protected.
In the short term, treatment must concentrate on infestations of Priority 1 species in areas of high biological
value, while larger infestations in low-quality areas must be monitored and contained until resources permit
more aggressive control of all infestations of the species.
Priority 2 species (Table 11.1b) pose somewhat less of an immediate threat to Monument resources than do
Priority 1 species but are still invaders of great concern. The principal characteristic distinguishing the two
ranks is one of reproductive biology: Priority 2 species do not spread as rapidly by seed as Priority 1 species.
Priority 2 species are perennial species that spread primarily by vegetative means, although new colonies are
initiated from time to time from seed. The weed management plan offers recommendations for treating
infestations of Priority 2 species in specific sites wherever small, isolated populations occur and where
Priority 2 species threaten high-quality natural areas, rare species, or other biological resources.
Priority 3 species include all other active list invasive species (Section 10, this volume). Priority 3 species are
perceived as less likely to increase, spread, or otherwise threaten Monument resources than Priority 1 and
Priority 2 species, but are still invasive species of concern. The weed management plan offers
recommendations for treatment of many Priority 3 species in specific sites, especially where these species
occur in isolated or satellite populations, or where they threaten high-quality natural areas, rare species, or
other biological resources.
INTEGRATED TREATMENT PROGRAM FOR PRIORITY SPECIES AND SITES
The invasive plant species management plan for the Hanford Reach National Monument provides a profile of
the ecology, reproductive characteristics, and impacts of each target invasive species, including a discussion
of integrated pest management (IPM) treatment options based upon invasive species literature (TNC 2003,
NWCB 2003b, William et al. 2002, Bossard et al. 2000, CNAP 2000, Sheley and Petroff 1999, and other
sources) and discussions with local professionals. Manual, mechanical, cultural, chemical, and biological
methods are available for the control and eradication of invasive species. The most appropriate treatment for
an infestation typically depends on the scale of the infestation and on the morphology and ecology of the
target species (Youtie 1997, S. Johnson pers. comm.). Biological control by itself may be effective for only a
few species. Viable biological controls are lacking for many species and, where available, are typically not
effective for small-scale infestations. Manual pulling or digging may effectively control small infestations of
annuals or biennial weeds but may be ineffective against larger infestations or against deep-rooted perennials.
Chemical control may be the most practical and effective option for small- to moderate-scale infestations of
perennial plant species but must be applied so as to minimize impacts on non-target plant species as well as
other organisms and systems. In actual practice, effective treatment for many weed infestations will require a
long-term, integrated approach utilizing all methods that are available. For example, pulling, mowing, or
burning at the most favorable time of year or plant developmental stage may enhance the effectiveness of later
chemical treatments, thus reducing the chemical inputs required for eradication or for a target level of control
(Renz 2000). Competitive plantings are also part of integrated weed management programs for many species,
and restoration with native plant species will inhibit recolonization of treated sites by undesirable species
(Brooks and Pyke 2001).
Treatment success is greatly enhanced by aggressive, early intervention at newly discovered, isolated satellite
weed occurrences. As mentioned above, timely intervention may reduce or, in some cases, even eliminate the
need for chemical inputs, reducing potential non-target impacts to desirable native species and to the
surrounding environment.

11. INVASIVE PLANT SPECIES MANAGEMENT PLAN FOR THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
124
With many invasive plant species, successful control of even small infestations requires several years of
treatment, often utilizing multiple treatments per year. A long-term perspective is particularly important for a
noxious perennial weed where total eradication is not a realistic short-term goal. Treatment success depends
as much upon long-term diligence as it does upon the methods used (Mack et al. 2000, Snyder-Conn 2001).
The duration of treatment required for a successful outcome is generally reduced by early detection and
timely treatment.
ADAPTIVE MANAGEMENT
The ongoing monitoring of weed populations and of the results of control programs will allow management to
evaluate the effectiveness of treatment methods in light of the site goals. Managers can then use this
information to modify and improve control priorities, methods, and plans. The modification of weed control
goals begins a new round of treatment, monitoring, and assessment.
BUILDING PARTNERSHIPS
Invasive plant species have impacts that ignore ownership and cross management boundaries. Effective weed
control efforts in one area can be nullified if similar measures are not taken simultaneously on neighboring
properties. Monument co-managers USFWS and DOE should coordinate weed control efforts closely.
Partnerships with other local and regional management entities can greatly increase efficiency in education,
detection, and treatment.
Monument co-managers already participate in valuable partnerships through the Noxious Weed Task Force,
an organization that originally formed around efforts to control saltcedar. Task Force members include federal
and state agencies (USFWS, DOE, WDFW, U.S. Bureau of Reclamation) along with local jurisdictions such
as county and district weed boards and public utility and irrigation districts. The Task Force has already
achieved important gains in outreach, detection, and treatment of saltcedar in the mid-Columbia region and
fostered a spirit of cooperative partnership among members (Hill 2003). These partnerships should be
maintained or expanded, and cooperative partnerships should be explored wherever opportunities are
perceived.
EDUCATION AND OUTREACH
Education and outreach regarding noxious weed identification and the ecological and economic impacts of
invasive species enhances the long-term success of weed management programs (Svejcar 1999). Adequate
training for field staff is critical. Educational programs should also reach out to non-field staff, partners,
landowners, public and private schools, user groups, and the public at large. Increasing public awareness can
lead to assistance in the prevention and early detection of weed occurrences. Avenues for educational
outreach can include workshops, brochures, interpretive displays at visitor centers, along roadsides, and at
community fairs and similar events.
FIRE MANAGEMENT
The unique role of wildfire in invasive species behavior in arid lands deserves mention. At Hanford as
throughout the arid West, the increase in both the frequency and extent of wildfires over the last half-century
is attributable in large part to invasive species and has created conditions that favor invasive plant species and
communities over native ones (Grace et al. 2001, Bushey 1995). Implementation of a fire management plan
aimed at maintaining fire frequencies at appropriate intervals for the perpetuation of intact native vegetation
will be a critical tool in limiting the spread and abundance of invasive plant species on the Hanford Reach
National Monument.

11. INVASIVE PLANT SPECIES MANAGEMENT PLAN FOR THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
125
Conclusions
The full weed management plan for the Hanford Reach National Monument is a detailed plan for the
management of invasive plant species that pose critical threats to the biological resources of the Monument.
The provisions in this plan can and should grow and change in response to changes in invasive species
populations, new information concerning either invasive species autecology or biological resources, advances
in weed technologies, and clarification of Monument conservation goals. Weed laws, personnel, conservation
goals, and even the invasive species of greatest concern may change over time, but invasive plant species will
remain a relatively constant threat to native biodiversity in the Columbia Basin. Effective management and
control of invasive plant species on the Hanford Reach National Monument will require a dedicated,
persistent, and long-term effort. Careful planning must be coupled with sufficient resources to sustain
determined and long-term inventory and control efforts in the field.

11. INVASIVE PLANT SPECIES MANAGEMENT PLAN FOR THE HANFORD REACH NATIONAL MONUMENT
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
126

Conclusions

BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
129
Conclusions
The predecessor to this report, the Biodiversity Inventory and Analysis of the Hanford Site (Soll et al. 1999),
convincingly documented the biological importance of the Hanford Site as a refuge for rare species of native
plants and animals and, as importantly, for common species and communities that were once far more
widespread in the inland Northwest. The biological studies outlined in this report continue to confirm
Hanford’s national and regional importance as a refuge both for biodiversity and for the natural processes that
characterize shrub-steppe and associated habitats. The large size of the Hanford Site as a whole, the continuity
of habitats between the Hanford Reach National Monument and Central Hanford, and the site’s proximity to
other important natural areas such as those on the Department of Defense’s Yakima Training Center
contribute to the importance of the Hanford Site as a reservoir of native biodiversity.
The biodiversity studies of the past decade have allowed us to learn a great deal about the natural systems of
the Hanford Site and to catalogue a diverse array of native organisms that populate these systems and
contribute to their natural processes. Current discoveries underline, in many ways, how our investigations
have still only begun to scratch the surface of the complex biology of this arid land.
Studies of aquatic and terrestrial invertebrates and of biological soil crusts continue to uncover new taxa and
provide new information regarding the distribution of these organisms across the landscape. Additional new
organisms may continue to be identified as researchers work through existing collections. It is likely, too, that
in these poorly known groups, taxa of biogeographic significance still remain uncollected. Although
researchers have begun to piece together the relationships between taxa and the environment, our
understanding of the function of these organisms in the ecosystems of the Lower Columbia Basin is still in its
infancy. Further inventories and ecological studies of these groups are likely to continue to yield important
discoveries.
Our knowledge of rare plant population trends is severely limited by a lack of information regarding life
history and reproductive strategies for most of these species. For the taxa that have been studied, our
knowledge is still often limited by the short time period during which we have been able to study these
populations. This is especially true for the Hanford endemics Umtanum desert buckwheat and White Bluffs
bladderpod, which were discovered less than 10 years ago. A much more long-term perspective is required to
adequately interpret the significance of perceived fluctuations in rare plant populations and thus provide
meaningful information to the agencies that manage these limited resources.
Plant communities as a whole change over time. Changes may be gradual, as in response to long-term
fluctuations in climate, or may occur rapidly in response to episodic events such as wildfires and other
disturbances. The vegetation maps produced by this and previous studies represent conditions at a single point
in time. However, plant communities are always dynamic elements in a landscape, and this is especially true
in shrub-steppe landscapes of the twentieth and twenty-first centuries. Plant community surveys must be
updated at least periodically, and in a timely manner when large-scale disturbance events dictate, in order to
remain fully valuable as management tools.
The warning sounded in Soll et al. (1999) regarding the threat posed by invasive species to the biodiversity of
the Hanford Site is even more pertinent today than it was four years ago. Invasive plant species are more
numerous and widespread than previous records indicate, and the areas they occupy are likely increasing. The
extent, distribution, and impacts of other invasive organisms, such as invertebrates, amphibians, birds, and
others, on the Hanford Site are poorly known and merit study as well. Invasive species populations are
dynamic and will continue to pose a challenge for natural resource managers into the foreseeable future, a

CONCLUSIONS
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
130
challenge that will likely become greater in an era of changing climate and increasing globalization of
commerce. Only a well-planned and coordinated invasive species management program, bolstered by
adequate staffing and resources, can be successful in protecting the natural resources and processes for which
the Hanford Reach National Monument was proclaimed and for which the entire Hanford Site is well known.
Given the dynamic environment of the Columbia River corridor, shrub-steppe uplands, and natural spring
streams of the Hanford Site, biological monitoring is a critical tool for the managers of the Hanford Reach
National Monument and Central Hanford. It will be essential to maintain up-to-date assessments of biological
resources, and the threats to those resources, in order to successfully manage the unique natural heritage of the
Hanford Site throughout the years ahead. Commitment to strong, ongoing biological monitoring programs is
highly recommended.
The biological inventories and ecological studies conducted at Hanford over the past decade have shown that
every management unit of the Hanford Reach National Monument and Central Hanford possesses important
resources that contribute to the overall biodiversity of the site and the region. These resources may be the
plants and animals themselves, or the biological and physical environments and habitat features on which the
organisms depend. It is important that these biological values be given strong consideration by the U.S. Fish
and Wildlife Service, the U.S. Department of Energy, and the engaged public in the course of planning for the
conservation, land use, and development of the Hanford Reach National Monument and the other lands of the
Hanford Site.

References

BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
133
References
Anderson, L.P. 2002. Population Genetics and Conservation of the Freshwater Mussel Margaritifera falcata
from the Northwestern United States. Unpubl MS Thesis. The University of Montana, 36 pp.
Auld, B.A., and B.G. Coote. 1980. A model of a spreading plant population. Oikos 34: 287-292.
Bauer, G., S. Hochwald, and W. Silkenat. 1991. Spatial Distribution of Freshwater Mussels; the Role of Host
Fish and Metabolic Rate. Freshwater Biology 26:277-386.
Baumann, R.W., A.R.Gaufin, and R.F.Surdick. 1977. The Stoneflies (Plecoptera) of the Rocky Mountains.
Memoirs of the American Entomological Society 31. 208 pp.
Beak Consultants Inc. 1980. Aquatic Ecological Studies Near WNP-1, 2 and 4. August 1978-March 1980.
WPPSS Columbia River Ecology Studies, Vol. 7. Report to the Washington Public Power Supply System.
Beak Consultants Inc., Portland, Oregon.
Becker, C.D. 1972a. Temperature and Development of Aquatic Invertebrates, in, Pacific Northwest
Laboratory, Annual Report 1971, Vol. 1 Life Sciences, Part 2 Ecological Sciences. BNWL-1650 PT2. Pacific
Northwest Laboratory, Richland, WA.
Becker, C.D. 1972b. Thermal Resistance of Aquatic Invertebrates, in, Pacific Northwest Laboratory, Annual
Report 1971, Volume 1 Life Sciences, Part 2 Ecological Sciences. BNWL-1650 PT2. Pacific Northwest
Laboratory, Richland, WA.
Becker, C.D. 1990. Aquatic Bioenvironmental Studies: The Hanford Experience 1944-84, Elsevier Science,
302 pp.
Belnap, J. 1994. Potential role of cryptobiotic soil crusts in semiarid rangelands. In Monsen, S.B., and S.G.
Kitchen (eds.), Proceedings: Ecology and Management of Annual Rangelands. General Technical Report
INT-GTR-313. U.S. Dept. of Agriculture, Forest Service, Intermountain Research Station. Pp. 179-185.
Belnap, J., and S.L. Phillips. 2001. Soil biota in an ungrazed grassland: Response to annual grass (Bromus
tectorum) invasion. Ecological Applications 11: 1261-1275.
Belnap, J., J. Kaltenecker, R. Rosentreter, J. Williams, S. Leonard, and D. Eldridge. 2001. Biological Soil
Crusts: Ecology and Management. Technical Report 1730-2, United States Department of the Interior.
Belnap, J. 1994. Potential role of cryptobiotic soil crusts in semiarid rangelands. In Monsen, S.B., and S.G.
Kitchen (eds.), Proceedings: Ecology and Management of Annual Rangelands. General Technical Report
INT-GTR-313. U.S. Dept. of Agriculture, Forest Service, Intermountain Research Station. Pp. 179-185.
Belnap, J. and J.S. Gardner. 1993. Soil microstructure in soils of the Colorado Plateau: the role of the
cyanobacterium Microcoleus vaginatus. Great Basin Naturalist 53: 40-47.
Bjornstad, B.N., K.R. Fecht, and C.F. Pluhar. 2001. Long history of pre-Wisconsin, ice age cataclysmic
floods: evidence from southeastern Washington state. Journal of Geology 109: 695–713.
Bogan, A.E. 1993. Freshwater Bivalve Extinctions (Mollusca:Unionidae): A search for causes. American
Zoology 33:599-609.
Bossard, C.C., J.M. Randall, and M.C. Hoshovsky. 2000. Invasive Plants of California Wildlands. University
of California Press, Berkeley, CA. 360 pp.
Bridges, D.C. 1994. Impact of weeds on human endeavors. Weed Technology 8: 392-395.

REFERENCES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
134
Brodo, I.M., S.D. Sharnoff, and S. Sharnoff. 2001. Lichens of North America. Yale University Press, New
Haven, CT. 795 pp.
Brookhart, J. Research Associate. Department of Zoology, Denver Museum of Nature and Science, Denver,
CO.
Brooks, M.L., and D.A. Pyke. 2001. Invasive plants and fire in the deserts of North America. In K.E.M.
Galley, and T.P. Wilson, eds. Proceedings of the Invasive Species Workshop: The Role of Fire in the Control
and Spread of Invasive Species. Tall Timbers Research Station Miscellaneous Publication No. 11: 1-14.
BFNA (Bryophyte Flora of North America Project). 2003. Buffalo Museum of Science, Buffalo, NY.
Available online at http://www.buffalomuseumofscience.org /BFNA/.
Burch, J.B. 1989. North American Freshwater Snails. Malacological Publications, Hamburg, Michigan. 365
pp.
Burch, J.B. 1972. Freshwater Sphaeriacean Clams (Mollusca:Pelecypoda) of North America. Environmental
Protection Agency, Biota of Freshwater Ecosystems, Identification Manual No. 3.
Bushey, C. 1995. Fire effects on noxious weeds within the Columbia River Basin. Science report, Interior
Columbia Basin Ecosystem Management Project. Available online at: http://www.icbemp.gov ( under
“Science Contract Reports, September 7, 1999”).
Caplow, F.E. 2003. Studies of Hanford Rare Plants, 2002. Washington Department of Natural Resources,
Natural Heritage Program, Olympia, WA. Report to The Nature Conservancy, Seattle, WA.
Camp, P. Botanist. U.S. Bureau of Land Management, Spokane, WA.
Chan, D. 2003. A study of the variation within Syntrichia ruralis in the Hanford area of Washington state.
Fourth year Honours Paper, University of British Columbia, Vancouver.
Clarke, A.H. 1981. The Freshwater Molluscs of Canada. National Museum of Natural Sciences, Ottawa,
Canada.
Clarke, A.H. 1976. Endangered Freshwater Mollusks of Northwestern North America. Bulletin of the
American Malacological Union 1976: 18-19.
Clarke, A.H. 1973. The Freshwater Molluscs of the Canadian Interior Basin. Malacologia 13. 510 pp.
CNAP (Colorado Natural Areas Program). 2000. Creating an Integrated Weed Management Plan: a
Handbook for Owners and Managers of Lands with Natural Values. Colorado Natural Areas Program,
Colorado State Parks, Colorado Dept. of Natural Resources, and Colorado Dept, of Agriculture, Division of
Plant Industry, Denver, CO. 349 pp.
Coopey, R.W. 1953. The Abundance of the Principal Crustacea of the Columbia River and the Radioactivity
They Contain. Document No. HW-25191. General Electric Co., for the U.S. Atomic Energy Commission. 15
pp.
Coopey, R.W. 1948. The Accumulation of Radioactivity as Shown by a Limnological Study of the Columbia
River in the Vicinity of the Hanford Works. U.S. Atomic Energy Commission, Report HW-11662, Hanford
Atomic Production Operations. 14 pp.
Coutant, C.C. 1968a. Effect of Temperature on the Development Rate of Bottom Organisms. In Annual
Report, BNWL-714,Vol. 1. Biological Sciences. Pacific Northwest Laboratory, Richland, WA.
Coutant, C.C. 1968b. Retention of Radionuclides in Columbia River Bottom Organisms. In Annual Report,
BNWL-714,Vol. 1. Biological Sciences. Pacific Northwest Laboratory, Richland, WA.
Coutant, C.C. 1966. Positive phototaxis in first instar caddis larvae. In R.C. Thompson and E.G. Swezea eds.,
Pacific Northwest Laboratory Annual Report 1965. BNWL-280. Pacific Northwest Laboratory, Richland,
WA.

REFERENCES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
135
Coutant, C.C. and C.D. Becker. 1970. Growth of the Columbia River limpet, Fisherola nuttalli (Haldeman).
In Normal and Reactor-Warmed Water. BNWL-1537. Pacific Northwest Laboratory, Richland, WA.
Coutant, C.C., D.G. Watson, C.E. Cushing, and W.L. Templeton. 1967a. Observations of the Life History of
the Limpet Snail Fisherola nutalli Haldemen. In R.C. Thompson and E.G. Swezea eds., Pacific Northwest
Laboratory Annual Report 1966, Vol.1 Biological Sciences. BNWL-480. Pacific Northwest Laboratory,
Richland, WA.
Coutant, C.C., D.G. Watson, C.E. Cushing, and W.L. Templeton. 1967b. Upstream dispersion of adult caddis
flies. In R.C. Thompson and E.G. Swezea eds., Pacific Northwest Laboratory Annual Report 1966, Vol.1
Biological Sciences. BNWL-480. Pacific Northwest Laboratory, Richland, WA.
Coutant, C.C., D.G.Watson, C.E.Cushing, and W.L.Templeton. 1967c. Retention of radionuclides in
Columbia River bottom organisms. In R.C.Thompson and E.G.Swezea eds., Pacific Northwest Laboratory
Annual Report 1966, Vol.1 Biological Sciences. BNWL-480. Pacific Northwest Laboratory, Richland, WA.
Crabo, L. In preparation. Moths of North America North of Mexico, Fascicle x.x. Wedge Entomological
Research.
Crawford, R. 1999. Preliminary Key to Shrubsteppe Plant Associations in Washington State. Unpublished
document on file at the Washington Natural Heritage Program Office, Department of Natural Resources,
Olympia. 40 pp.
Cuffney, T.F., M.R. Meador, S.D. Porter, and M.E. Gurtz. 1997. Distribution of Fish, Benthic Invertebrate,
and Algal Communities in Relation to Physical and Chemical Conditions, Yakima River Basin, Washington,
1990. U.S.G.S. Water Resources-Investigations Report 96-4280, 94 pp.
Cushing, C.E. and E.G. Wolf. 1984. Primary production in Rattlesnake Springs, a cold desert spring-stream.
Hydrobiologia 114:229-236.
Cushing, C.E. and E.G. Wolf. 1982. Organic energy budget of Rattlesnake Springs, Washington. American
Midland Naturalist 107: 404-407.
Cushing, C.E. and R.T. Rader. 1982. A note on the food of Callibaetis (Ephemeroptera:Baetidae). Great
Basin Naturalist 41(4):431-432.
Daubenmire, R. 1970. Steppe Vegetation of Washington. Washington Agricultural Experiment Station
Technical Bulletin 62. Washington Agricultural Experiment Station, Pullman, WA.
Dauble, D.D., R.H. Gray, and T.L. Page. 1980. Importance of insects and zooplankton in the diet of 0-age
chinook salmon (Oncorhynchus tshawytscha) in the central Columbia River. Northwest Science 54(4): 253-
258.
Davis, J.J. and C.L. Cooper. 1951. Effect of Hanford Pile Effluent Upon Aquatic Invertebrates in the
Columbia River. Document No. HW-20055, U.S. Atomic Energy Commission, Hanford Works, Richland,
WA.
De Grandpré, L., J. Morissette, and S. Gauthier. 2000. Long-term post-fire changes in the northeastern boreal
forest of Quebec. Journal of Vegetation Science 11: 791–800.
Di Maio, J. and L.D. Corkum. 1995. Relationship between the spatial distribution of freshwater mussels
(Bivalvia:Unionidae) and the hydrological variability of rivers. Canadian Journal of Zoology 73: 663-671.
DiTomaso, J.M. 2000. Invasive weeds in rangelands: Species, impacts, and management. Weed Science 48:
255-265.
DOE-RL (U.S. Department of Energy, Richland Operations Office). 2001. Hanford Site Biological Resources
Management Plan. DOE/RL 96-32. U.S. Department of Energy, Richland, WA.

REFERENCES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
136
Downs, J.L., W.H. Rickard, C.A. Brandt, L.L. Cadwell, C.E. Cushing, D.R. Geist, R.M. Mazaika, D.A.
Neitzel, L.E. Rogers, M.R. Sackschewsky, and J.J. Nugent. 1993. Habitat Types on the Hanford Site: Wildlife
and Plant Species of Concern. Pacific Northwest Lab., Report No. PNL-8942, Battelle, Richland, WA.
Dresser, T. Fisheries Scientist. Grant County Public Utility District No. 2. Ephrata, WA.
Dunwiddie, P.W., K.A. Beck, and F.E. Caplow. 2000a. Demographic studies of Eriogonum codium Reveal
Caplow & Beck (Polygonaceae) in Washington. Pp 60-70 in, S.H. Reichard, P. W. Dunwiddie, J.G. Gamon,
A.R. Kruckeberg. and D. L. Salstrom (eds.), Conservation Of Washington’s Native Plants And Ecosystems.
Washington Native Plant Society, Seattle, WA.
Dunwiddie, P.W., K.A. Beck, and F.E. Caplow. 2000b. Demographic Studies on Lesquerella tuplashensis
Rollins, Beck & Caplow (Brassicaceae) in Washington. Unpublished paper presented at the Washington Rare
Plants Conference, April 17-18, 2000, Seattle, WA.
Easterly, R.T. and D.L. Salstrom. 2003. Current Vegetation Map of Mcgee Ranch–Riverlands Unit, Hanford
Reach National Monument. Report to The Nature Conservancy, Seattle, WA. 10 pp.
Easterly, R.T. and D.L. Salstrom. 2002a. Current vegetation map: shrub-steppe of East Satus: Yakama
Nation. Unpublished report and map submitted to Yakama Nation Wildlife Resources, Toppenish, WA. 11pp.
+ maps.
Easterly, R.T. and D.L. Salstrom. 2002b. Current vegetation map of the Ginkgo-Wanapum State Park.
Unpublished report and map submitted to WA State Parks and Recreation Commission, Olympia. 8 pp. +
maps.
Easterly, R.T. and D.L. Salstrom. 2001. Vegetation map of the riparian area of the north shore, and revisions
to the map of the south shore, of the Hanford Reach, Columbia River. Unpublished map submitted to Battelle,
Pacific Northwest National Laboratory, Richland, Washington.
Easterly, R.T. and D.L. Salstrom. 1999. Vegetation cover map of the Yakima Training Center. Unpublished
report and map submitted to Battelle Pacific Northwest National Laboratories, Richland, WA. 6pp. + maps.
Easterly, R.T. and D.L. Salstrom. 1998. Vegetation cover map, Yakima Training Center Sage Grouse
Conservation Area. Unpublished letter report and map submitted to Battelle Pacific Northwest National
Laboratories, Richland, WA. 3 pp. + maps.
Easterly, R.T. and D.L. Salstrom. 1997. Central Hanford 1997 plant community inventory. Unpublished
report and map submitted to The Nature Conservancy, Washington Field Office, Seattle. 43 pp. + maps.
Edmunds, G.F., Jr. 1960. The mayfly genus Baetisca in Western North America
(Ephemeroptera:Baetiscidae). Pan-Pacific Entomologist 36(2):102-104.
Eldridge, D.J. 1993. Cryptogam cover and soil surface condition: effects on hydrology on a semiarid
woodland soil. Arid Soil Research and Rehabilitation 7: 203-217.
Eldridge, D.J. and P.I.A. Kinnell. 1997. Assessment of erosion rates from microphyte-dominated calcareous
soils under rain-impacted flow. Australian Journal of Soil Research 32: 475-489.
Elrod, M.J. 1902. A Biological Reconnaissance in the Vicinity of Flathead Lake. Bulletin of the University of
Montana, No.10, Biolological Series No. 3: 91-180.
Emery, R.M. and M.C. McShane. 1978. Comparative ecology of nuclear waste ponds and streams on the
Hanford Site. PNL-2499. Pacific Northwest Laboratory, Richland, WA.
Energy Research and Development Administration (ERDA). 1975. Final Environmental Statement, Waste
Management Operations. ERDA-1538, Vol. 2. Energy Research Development Administration, Richland,
WA.

REFERENCES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
137
Evans, J.R., J.J. Nugent, and D.E. Ekblaw. 2002. Short Term Impacts of the 24 Command Fire on Vegetation
of the Fitzner-Eberhardt Arid Lands Ecology Reserve, Hanford Reach National Monument: Synthesis of
Findings, 2001 – 2002. Report to the U.S. Fish and Wildlife Service, Hanford Reach National Monument.
The Nature Conservancy of Washington, Seattle, WA.
Evans, J.R., J.J. Nugent, and J. Meisel. 2003. Invasive Plant Species Inventory and Management Plan for the
Hanford Reach National Monument. The Nature Conservancy, Seattle, WA.
Evans, R.D., R. Rimer, L. Sperry, and J. Belnap. 2001. Exotic plant invasion alters nitrogen dynamics in an
arid grassland. Ecological Applications 11: 1301-1310.
Evans, R.D. and J. Belnap. 1999. Long-term consequences of disturbance on nitrogen dynamics in an arid
ecosystem. Ecology 80: 150-160.
Evans, R.D. and J.R. Johansen. 1999. Microbiotic crusts and ecosystem processes. Critical Reviews in Plant
Sciences 18: 183-225.
Eyerdam, W.J. 1934. Land and freshwater shells from the vicinity of Yakima, Washington. The Nautilus
48:46-48.
Flowers, S. 1973. Mosses: Utah and the West. Brigham Young Univ. Press, Provo, UT. 567 pp.
Franklin, J.F., and C.T. Dyrness. 1973. Natural Vegetation of Oregon and Washington. Oregon State
University Press, Corvallis, OR.
Framatome ANP DE&S. 2003. Research summary and threats assessment for Artemisia campestris subsp.
borealis var. wormskioldii. Draft report to Grant County PUD no. 2, Ephrata, WA.
Frest, T.J. and E.J. Johannes. 1995. Interior Columbia Basin Mollusk Species of Special Concern. Report to
Interior Columbia Basin Ecosystem Management Project, Walla Walla, WA, 274 pp.
Frest, T.J. and E.J. Johannes. 1993a. Mollusc Survey of the Hanford Site, Benton and Franklin Counties,
Washington. PNL-8653, Pacific Northwest Laboratory, Richland, WA.
Frest, T.J. and E.J. Johannes. 1993b. Freshwater Molluscs of the Upper Sacramento System with Particular
Reference to the Cantara Spill. 1992 Yearly Report to California Department of Fish & Game. Deixis
Consultants, Seattle, WA. 101 pp.
Frest, T.J. and E.J. Johannes. 1992. Effects of the March 1992 Drawdown on the Freshwater Molluscs of the
Lower Granite Lake Area, Snake River, SE WA and W. ID. Final Report to the U.S. Army Corps of
Engineers, Walla Walla District. Deixis Consultants, Seattle, WA. 11 pp.
Frest, T.J. and E.J. Johannes. 1991. Mollusc Fauna in the Vicinity of Three Proposed Hydroelectric Projects
on the Middle Snake River, Central Idaho. Final Report to Don Chapman Consultants, Inc. Boise, Idaho.
Deixis Consultants, Seattle, WA, 60 pp.
Gaines, W.E. 1987a. Secondary Production of Benthic Insects in Three Cold Desert Streams. Pacific
Northwest Laboratory, PNL-6286, Richland, WA.
Gaines, W.E. 1987b. Secondary Production of Benthic Insects in Three Cold-Desert Streams. Unpubl.
Masters Thesis, Central Washington University, Ellensburg, WA.
Gaines, W.L., C.E. Cushing, and S.D. Smith. 1992. Secondary Production Estimates of Benthic Insects in
Three Cold Desert Streams. Great Basin Naturalist, 52:11-24.
Gaines, W.L., C.E. Cushing, and S.D. Smith. 1989. Trophic Relations and Functional Group Composition of
Benthic Insects in Three Cold Desert Streams. Southwestern Naturalist 34:478-482.
Gehring, J. 1994. Growth and reproduction of Rorippa columbiae on the Columbia River, 1990-1993. Report
to The Nature Conservancy, Seattle, WA.

REFERENCES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
138
Gehring, J. 1992. 1991 Survey of Rorippa columbiae on Pierce Island. Report to The Nature Conservancy,
Seattle, WA.
Goff, F.E. 1981. Preliminary geology of eastern Umtanum Ridge, south-central Washington. Rockwell
Hanford Operations RHO-BWI-C-21, 99 pp.
Goward, T., B. McCune, and D. Meidinger. 1994. The lichens of British Columbia Part 1: Foliose and
squamulose lichens. B.C. Ministry of Forests, Victoria. 181 pp.
Goward, T. Curator of Lichen Collections. University of British Columbia Herbarium, Vancouver, BC,
Canada.
Grace, J.B., M.D. Smith, S.L. Grace, S.L. Collins, and T.J. Stohlgren. 2001. Interactions between fire and
invasive plants in temperate grasslands of North America. In K.E.M. Galley, and T.P. Wilson, eds.
Proceedings of the Invasive Species Workshop: The Role of Fire in the Control and Spread of Invasive
Species. Tall Timbers Research Station Miscellaneous Publication No. 11: 40-65.
Grissell, E. E. and R. S. Zack. 1996. Torymidae (Hymenoptera) new to Washington state. Proceedings of the
Entomological Society of Washington 98: 827-828.
Habegger, E., P. Dunwiddie, and J. Gehring. Effects of river level on population dynamics of Rorippa
columbiae on Pierce Island, Washington. In S.H. Reichard, P.W. Dunwiddie, J.G. Gamon, A.R. Kruckeberg.
and D.L. Salstrom, eds., Conservation of Washington’s Native Plants And Ecosystems. Washington Native
Plant Society, Seattle, WA.
Hall, J.A. 1998. Biodiversity Inventory and Analysis of the Hanford Site: 1997 Annual Report, The Nature
Conservancy of Washington, Seattle, WA. 47 pp.
Hanson, W.C., and L.L. Eberhardt. 1971. A Columbia River Canada goose population. Wildlife Monographs
28: 1-61.
Harris, P. 1992. Hydrology and water management of the Hanford Reach of the Columbia River and its effect
on Rorippa columbiae habitat. Report to The Nature Conservancy, Seattle, WA.
Heard, W.H. 1970. Hermaphroditism in Margaritifera falcata. The Nautilus 83: 113-114.
Henderson, J. 1936a. Mollusca of Colorado, Utah, Montana, Idaho and Wyoming—Supplement. University
of Colorado Studies 23:81-145.
Henderson, J. 1936b. The Non-marine Mollusca of Oregon and Washington—Supplement. University
Colorado Studies 23:251-280.
Henderson, J. 1929. Non-marine Molluscs of Oregon and Washington. University of Colorado Studies, 17:47-
190.
Hershler, R. and T.J. Frest. 1996. A Review of the North American Freshwater Snail Genus Fluminicola
(Hydrobiidae). Smithsonian Contributions to Zoology 583:1-41.
Hill, R. 2003. Saltcedar Eradication in Washington State. Completion Report: Pulling Together Initiative
Project #2001-0028-024. U.S. Fish and Wildlife Service, Columbia National Wildlife Refuge, Othello, WA.
Hitchcock, C.L., and A. Cronquist. 1973. Flora of the Pacific Northwest. University of Washington Press,
Seattle, WA.
Hitchcock, C.L., A. Cronquist, M. Ownbey, and J.W. Thompson. 1955. Vascular Plants of the Pacific
Northwest, Part 5: Compositae. University of Washington Press, Seattle, WA. 343 pp.
HMS (Hanford Meteorological Station). 2002. Hanford Meteorological Station, Richland, WA. February 6,
2003. Available online at http://terrassa.pnl.gov:2080/HMS/products.htm
Holm, L.G., J.V. Pancho, J.P.Herberger, and D.L. Plucknett. 1977. The World’s Worst Weeds: Distribution
and Biology. University of Hawai’i Press, Honolulu, HI. 609 pp.

REFERENCES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
139
HRNM (Hanford Reach National Monument). 2003. Data from geographic information system database.
Hanford Reach National Monument/Saddle Mountain National Wildlife Refuge, Richland, WA.
Ingram, W.M. 1948. The larger freshwater clams of California, Oregon, and Washington. Journal of
Entomology and Zoology, 40:72-92.
Jensen, M.N. 2001. Weed eating insects munch wrong plants. Academic Press Daily InScight, August 2,
2001. www.academicpress.com/inscight/08022001/grapha.htm
Johansen, J.R, J. Ashley, and W.R. Rayburn. 1993. Effects of rangefire on soil algal crusts in semiarid shrub-
steppe of the lower Columbia Basin and their subsequent recovery. Great Basin Naturalist 53: 73-88.
Johnson, S. Region 1 Integrated Pest Management Coordinator. U.S. Fish and Wildlife Service, Vancouver,
WA.
Kaltenecker, J.H., M.C. Wicklow-Howard, and K. Larsen. 1999. Biological soil crusts: natural barriers to
Bromus tectorum establishment in the Northern Great Basin, USA. In P.G. Entwhistle, A.M. DeBolt, J.H.
Kaltenecker, and J. Steenhof (compilers), Proceedings: Sagebrush Steppe Ecosystems Symposium. Bureau of
Land Management Publication No. BLM/ID/PT-001001+1150. Boise, ID. Pp. 115. Available online at:
http://www.id.blm.gov/publications/data/SSSymp.pdf
Kaltenecker, J., and M. Wicklow Howard. 1994. Microbiotic Soil Crusts in Sagebrush Habitats of Southern
Idaho. Report prepared for the Eastside Ecosystem Management Project. Interior Columbia Basin Ecosystem
Management Project. 48 pp. Available online at: http://www.icbemp.gov/)
Karr, J. 2000. Fire and ecological health at Hanford and Los Alamos. Institute for Responsible Management,
Consortium for Risk Evaluation with Stakeholder Participation II, Ecological Health Task Group. Available
online at: http://www.cresp.org/fire.html
Kartesz, J.T., and C.A. Meacham. 1999. Synthesis of the North American Flora. CD-ROM version 1.0. North
Carolina Botanical Garden, Chapel Hill, NC.
Kaye, T. 1996. Conservation strategy for Rorippa columbiae (Columbia cress). U.S. Department of the
Interior, Bureau of Land Management, Wenatchee, WA.
Kenkel, N.C. and L. Orloci. 1986. Applying metric and nonmetric multidimensional scaling to ecological
studies: some new results. Ecology 67: 919-928.
Koenig, S. 2000. Relation of Physical Factors to the Behavior and Distribution of the Freshwater Mussel,
Margaritifera falcata (Gould). Unpublished MS Thesis, Western Washington University, Bellingham, WA.
66 pp.
Lawton, E. 1971. Moss flora of the Pacific Northwest. The Hattori Botanical Laboratory, Nichinan, Miyazaki,
Japan. 362 pp.
Lehrsch, G.A., F.D. Whisler, and J.J. Romkens. 1988. Spatial variation of parameters describing soil surface
roughness. Soil Science Society of America Journal 52: 311-319.
Leonard, R. Moses Coulee/Beazly Hills Weed Coordinator. The Nature Conservancy, Wenatchee, WA.
Lindberg, J.W. 1994. Geology of the McGee Ranch Site, Area B: Phase II Characterization, WHC-SD-EN-
TI-206, Rev. 0, Westinghouse Hanford Company, Richland, Washington. 27 pp.
Link, S.O., B.D. Ryan, J.L. Downs, L.L. Cadwell, J.A. Soll, M.A. Hawke, and J. Ponzetti. 2000. Lichens and
mosses on shrub-steppe soils in southeastern Washington. Northwest Science 74: 50-56.
LTABC (The Land Trust Alliance of British Columbia). 2002. The Land Trust Alliance of British Columbia.
Salt Spring Island, BC, Canada. Available online at: http://www.landtrustalliance.bc.ca/registry
Lyman, R.L. 1980. Freshwater bivalve molluscs and southern plateau prehistory: A discussion and
description of three genera. Northwest Science 54:121-136.

REFERENCES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
140
Mack, R.N., D. Simberloff, W.M. Lonsdale, H. Evans, M. Clout, and F.A. Bazzaz. 2000. Biotic invasions:
Causes, epidemiology, global consequences, and control. Ecological Applications 10: 689-710.
McCabe, G.T.,Jr., S.A. Hinton and R.L. Emmett. 1998. Benthic invertebrates and sediment characteristics in a
shallow navigation channel of the Lower Columbia River, before and after dredging. Northwest Science,
72:116-126.
McCabe, G.T., Jr., S.A. Hinton, R.L. Emmett, and B.P. Sandford. 1997. Benthic invertebrates and sediment
characteristics in main channel habitats in the lower Columbia River. Northwest Science, 71:45-55.
McCune, B., F. Camacho, and J. Ponzetti. 2002. Three new species of Trapeliopsis on soil in western North
America. The Bryologist 105: 78-86.
McCune, B. and J.B. Grace. 2002. Analysis of Ecological Communities. MjM Software Design, Glenedon
Beach, OR. 300 pp.
McCune, B. and M.J. Mefford. 1999. PC-ORD. Multivariate analysis of ecological data. Version 4.0. MjM
Software Design, Glenedon Beach, OR.
McCune, B. and R. Rosentreter. 1995. Field key to soil lichens of central and eastern Oregon. Unpublished
manuscript.
McCune, B. and R. Rosentreter. 1992. Texosporium sancti-jacobi, a rare western North American lichen. The
Bryologist 95(3): 329-333.
McCune, B. Professor, Department of Botany & Plant Pathology. Oregon State University, Corvallis, OR.
McGuire, D.L. and D. Marshall. 2001. Current Distribution of the Western Pearl Mussel, Margaritifera
falcata, on the Flathead Reservation. Unpublished internal report for the Confederated Salish and Kootenai
Tribes, Montana, 7 pp.
McIntosh, T.T. 2003. An Assessment of Lichen and Bryophyte Biodiversity and Biological Soil Crust
Relationships in the Hanford Reach National Monument. Report to The Nature Conservancy, Seattle, WA.
McIntosh, T.T. 1989. New and interesting bryophytes of the semi-arid steppe of British Columbia, including
four species new to North America. The Bryologist 92(3): 292-295.
McIntosh, T.T. 1986. The bryophytes of the semi-arid steppe of south-central British Columbia. Ph.D.
Dissertation. Botany Department, University of British Columbia, Vancouver.
McNeely, J.A. 2001. The Great Reshuffling: Human Dimensions of Invasive Alien Species. IUCN, Gland,
Switzerland and Cambridge, UK. 242 pp.
Marceau, T.E. Bechtel Hanford Inc., Richland WA.
Merritt, R.W. and K.W. Cummins. 1996. An Introduction to the Aquatic Insects of North America.
Kendall/Hunt Publishing, Dubuque, IA. 876 pp.
Mitchell, J.E. 2000. Rangeland resource trends in the United States. Gen. Tech. Report RMRS-GTR-68. U.S.
Forest Service Rocky Mt. Research Station, Ft. Collins, CO. 84 pp.
Mize, A.L. 1993. Differential Utilization of Allochthonous and Autochthonous Carbon by Aquatic Insects of
Two Shrub-Steppe Desert Spring-Streams: A Stable Carbon Isotope Analysis and Critiques of the Method.
Pacific Northwest Laboratory, PNL-8684, Battelle, Richland, WA.
Moody, M.E., and R.N. Mack. 1988. Controlling the spread of plant invasions: the importance of nascent
foci. Journal of Applied Ecology 25: 1009-1021.
Mullins, B.H., L.W.J. Anderson, J.M. DiTomaso, R.E. Eplee, and K.D. Getsinger. 2000. Invasive Plant
Species. Issue Paper 13. Council for Agricultural Science and Technology, Ames, Iowa. 18 pp.
Murphy, G. 1942. Relationship of the freshwater mussel to trout in the Truckee River. California Fish and
Game 28(2): 89-102.

REFERENCES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
141
Myers, T.R. 1974. Comparative Susceptability of Juvenile Salmonid Fishes to Infection with the Glochidia of
Margaritifera margaritifera (L.) (Plecypoda:Margaritanidae). Unpublished MS Thesis, Oregon State Univ.,
Corvallis, OR, 87 pp.
NatureServe. 2002. Draft Element Occurrence Data Standard. In cooperation with the Network of Natural
Heritage Programs and Conservation Data Centers. February 6 edition. 201 pp. Available online at
http://whiteoak.natureserve.org/eodraft/index.htm
NPS (U.S. National Park Service). 1994. Hanford Reach of the Columbia River, Final Environmental Impact
Statement. U.S. National Park Service.
Neitzel, D.A., (ed.). 1998. Hanford Site National Environmental Policy Act (NEPA) Characterization. PNNL-
6415 Rev. 10. Pacific Northwest National Laboratory, Richland, Washington.
Neitzel, D.A. and T.J. Frest. 1993. Survey of Columbia River Basin Streams for Columbia Pebblesnail
Fluminicola columbiana and Shortface Lanx, Fisherola nuttalli. PNL-8229. Pacific Northwest Laboratory,
Richland, WA.
Neitzel, D.A. and T.J. Frest. 1989. Survey of the Columbia River Basin Streams for Giant Columbia River
Spire Snail, Fluminicola columbiana and Great Columbia River Limpet, Fisherola nuttalli. PNL-7103,
Pacific Northwest Laboratory, Richland, WA.
Neuman, C.M. and C. Maxwell. 1999. A wind tunnel study of the resilience of three fungal crusts to particle
abrasion during Aeolian sediment transport. Catena 38: 151-173.
Newell, R.L. 2003. Biodiversity of aquatic macroinvertebrates of the Hanford Reach National Monument,
Washington, U.S.A. Report to The Nature Conservancy, Seattle, WA.
Newell, R.L. 1998. Diversity of Aquatic Invertebrates of the Hanford Reach of the Columbia River, Some
Tributaries and Two Adjacent Springs, Washington state, U.S.A. Report To The Nature Conservancy of
Washington, 34 pp.
Newell, R.L., D. Ruiter, and D. Strenge. 2001. Adult caddisfly (Trichoptera) phenology in two cold-desert
endorheic spring-streams in Washington state. Pan-Pacific Entomologist 77: 190-195.
NWCB (Washington State Noxious Weed Control Board). 2003a. State noxious weed list. Available online
at: http://www.wa.gov/agr/weedboard/
NWCB (Washington State Noxious Weed Control Board). 2003b. Weed Information. Washington State
Noxious Weed Control Board website. Available online at: http://www.nwcb.wa.gov/INDEX.htm
O’Brien, C.W. and R.S. Zack. 1997. Weevils new to the state of Washington (Coleoptera: Curculionidae).
Pan-Pacific Entomologist 73: 58-59.
Parker, M.B. 1979. Tales of Richland, White Bluffs and Hanford 1805-1943: Before the Atomic Reserve. Ye
Galleon Press. Fairfield, Washington. 407 pp.
Pauley, G.B. 1968. Tumor Incidence Among Freshwater Mussel Populations. In, Annual Report 1967, Vol.1:
Biological Sciences. BNWL-714. Pacific Northwest Laboratory, Richland, WA.
Paulson, D.R. 1998. The Odonata of Washington. Unpublished taxonomic keys and county distribution
records.
Pennak, R.W. 1989. Fresh-water Invertebrates of the United States. J. Wiley & Sons., NY. 656 pp.
Penny, N.D. Department of Entomology, California Academy of Sciences, San Francisco, CA.
Pickel, M.E. 2000. The Composition, Diversity, and Density of Benthic Macroinvertebrates in Shrub-Steppe
Cold-Water Springs. Unpublished M.S. Thesis, Washington State University/Tri-Cities, Richland, WA.
PNEPPC (Pacific Northwest Exotic Pest Plant Council). 1997. Preliminary List of Exotic Pest Plants of
Greatest Ecological Concern in Oregon and Washington. Available online at:
http://www.wnps.org/eppclet.html

REFERENCES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
142
PNL (Pacific Northwest Laboratory). 1979a. Aquatic Ecological Studies Near WNP-1, 2, and 4, September
1974–September 1975. Washington Public Power Supply System, Columbia River Ecology Studies, Vol. 2.
Pacific Northwest Laboratory, Richland, Washington.
PNL (Pacific Northwest Laboratory). 1979b. Aquatic Ecological Studies Near WNP-1, 2, and 4, January–
December 1977. Washington Public Power Supply System, Columbia River Ecology Studies, Vol. 5. Pacific
Northwest Laboratory, Richland, Washington.
PNL (Pacific Northwest Laboratory). 1979c. Aquatic Ecological Studies Near WNP-1, 2 and 4, January
through August 1978. Washington Public Power Supply System, Columbia River Ecology Studies, Vol. 6.
Pacific Northwest Laboratory, Richland, Washington.
PNL (Pacific Northwest Laboratory). 1978. Aquatic Ecological Studies Near WNP-1, 2 and 4, March through
December 1976. Washington Public Power Supply System, Columbia River Ecology Studies, Vol. 4. Pacific
Northwest Laboratory, Richland, Washington.
PNL (Pacific Northwest Laboratory). 1977. Aquatic Ecological Studies Near Washington Nuclear Plants
(WNP)-1, 2 and 4, October 1975 through February 1976. Washington Public Power Supply System,
Columbia River Ecology Studies, Vol. 3. Pacific Northwest Laboratory, Richland, Washington.
PNL (Pacific Northwest Laboratory). 1976. Final Report on Aquatic Ecological Studies Conducted at the
Hanford Generating Project, 1973-74. Washington Public Power Supply System, Columbia River Ecology
Studies, Vol. 1. Pacific Northwest Laboratory, Richland, Washington.
PNNL (Pacific Northwest National Laboratory). 2002. Hanford Site vegetation cover map. Ecosystem
Monitoring Project. Pacific Northwest National Laboratory, Richland, WA. Available online at:
www.pnl.gov/ecology/ecosystem/Veg/vegmap.html
PNNL (Pacific Northwest National Laboratory). 1998. Hanford Site National Environmental Policy Act
(NEPA) Characterization. PNNL-6415 Rev. 10. Pacific Northwest National Laboratory, Richland, WA.
Ponzetti, J. 2000. Biotic Soil Crusts of Oregon’s Shrub Steppe. MS Thesis, Oregon State University, Corvalis.
Ponzetti, J., B. McCune, and D. Pyke. 2000. Biotic crusts on a central Washington landscape. Report to the
Bureau of Land Management. 44 pp.
Presidential Proclamation 7319 of June 9, 2000. Establishment of the Hanford Reach National Monument.
William J. Clinton, President of the United States. Federal Register 65 (114): 37253-37257. June 13, 2000.
Pyke, C.R., R. Condit, S. Aguilar, and S. Lao. 2001. Floristic composition across a climatic gradient in a
neotropical lowland forest. Journal of Vegetation Science 12: 553-566.
Qian, H., K. Klinka, R.H. Økland, P. Krestov, and G.J. Kayahara. 2003. Understory vegetation in boreal
Picea mariana and Populus tremuloides stands in British Columbia. Journal of Vegetation Science 14: 173-
184.
Randall, J.M. 1996. Weed control for the preservation of biological diversity. Weed Technology 10: 370-383.
Reidel, S.P and K.R. Fetch. 1994. Geologic map of the Priest Rapids 1:100,000 quadrangle, Washington:
Washington Division of Geology and Earth Resources Open File Report 94–13.
Renz, M.J. 2000. Element Stewardship Abstract for Lepidium latifolium. The Nature Conservancy Wildland
Invasive Species Program. Available at: http://tncweeds.ucdavis.edu/index.html
Reveal, J.L., F.E. Caplow, and K.A. Beck. 1996. Eriogonum codium, a new species from southeastern
Washington. Rhodora 97: 350-356.
Rice, P.M. 2002. INVADERS Database System, Division of Biological Sciences, University of Montana,
Missoula, MT. Available online at: http://invader.dbs.umt.edu
Rickard, W.H. 1970. The distribution of ground-dwelling beetles in relation to vegetation, season, and

REFERENCES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
143
topography of Rattlesnake Hills, southeastern Washington. Northwest Science 44: 107-113.

REFERENCES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
144
Rickard, W.H., J.H. Cline, and R.O. Gilbert. 1974. Pitfall trapping and direct counts of darkling beetles in
cheatgrass communities. Northwest Science 48: 96-101.
Rickard, W.H. and L.E. Haverfield. 1965. A pitfall trapping survey of darkling beetles in desert steppe
vegetation. Ecology 46: 873-877.
Rickard, W.H., L.E. Rogers, B.E. Vaughan, and S.F. Liebetrau. 1988. Shrub-Steppe: Balance and Change in a
Semi-Arid Terrestrial Ecosystem. Elsevier, NY.
Ridenour, W.L. and R.M. Calloway. 1997. The effects of Cryptogamic soil crusts on Festuca idahoensis and
Artemisia tridentata in the sagebrush steppe of western Montana. Bulletin of the Ecological Society of
America 78 (Suppl. 4): 302.
Rogers, L.E. 1979. Shrub-inhabiting insects of the 200 area plateau, southcentral Washington. PNL-2713.
Pacific Northwest Laboratory, Richland, WA.
Rogers, L.E., N. Woodley, J.K. Sheldon, and V.A. Uresk. 1978. Darkling beetle populations (Tenebrionidae)
at the Hanford Site in southcentral Washington. PNL-2465. Pacific Northwest Laboratory, Richland,
Washington.
Rollins, R.C., K.A. Beck, amd F.E. Caplow. 1995. An undescribed species of Lesquerella (Cruciferae) from
the State of Washington. Rhodora 97: 201-207.
Roos, R. Hanford Biological ControlProgram, Duratek Inc.
Roscoe, E.J. and S. Redelings. 1964. The Ecology of the Freshwater Pearl Mussel Margaritifera
margaritifera (L.). Sterkiana 16: 19-32.
Rosentreter, R. 1998. Notes on the Aspicilia reptans complex, with descriptions of two new species. In MG.
Glenn, R.C. Harris, R. Dirig and M.S. Cole Lichenographia Thompsoniana: North American Lichenology in
Honor of John W. Thomson. 445 pp.
Rosentreter, R., D.J. Eldridge, and J.H. Kaltenecker. 2001. Monitoring and management of biological soil
crusts. Ecological Studies 150: 457-468.
Rossman, A.Y. 1977. Cryptogamic plants of the Lawrence Memorial Grassland Reserve. Unpublished report
prepared for The Nature Conservancy, Inc. 22 pp.
Sackschewsky, M.R. and J.L. Downs. 2001. Vascular Plants of the Hanford Site. United States Department of
Energy (DOE). PNNL-13688.
Salstrom, D. and J. Gehring. 1994. Report on the status of Rorippa columbiae Suksdorf ex. Howell.
Washington Department of Natural Resources, Natural Heritage Program, Olympia, WA.
Salstrom, D.L. and R.T. Easterly. 1995. Riparian plant communities: south shore and islands of the Columbia
River on the Hanford Site, Washington. Unpublished report to The Nature Conservancy, Washington Field
Office, Seattle.
Sauer, R. and J. Leder. 1985. The status of persistentsepal yellowcress in Washington. Northwest Science
59:198-203.
Schulten, J.A. 1985. Soil aggregation by cryptogams of a sand prairie. American Journal of Botany 72: 1657-
1661.
Schwab, G.E., R.M. Colpitts Jr., and D.A. Schwab. 1979. Spring Inventory of the Rattlesnake Hills. W.K.
Summers and Associates, Inc., Socorro, New Mexico.
Sheldon, J.K. and L.E. Rogers. 1978. Grasshopper food habits within a shrub-steppe community. Oecologia
32: 85-92.
Sheley, R.S., and J.K. Petroff. 1999. Biology and Management of Noxious Rangeland Weeds. Oregon State
University Press, Corvallis, OR. 438 pp.

REFERENCES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
145
Simmons, S. 2000. The status of Rorippa columbiae and Lesquerella douglasii on the Hanford Reach of the
Columbia River in south central Washington. Unpublished dissertation. Washington State University,
Pullman, WA.
Snyder-Conn, E. 2001. Memorandum on Conditional Approval of Pesticide Use Permits R1-01-13700-01,
-04, and -10 for use of Transline, Arsenal/Rodeo, and Oust at Hanford Reach National Monument and Saddle
Mountain National Wildlife Refuge. National Pets Management Coordinator, U.S. Fish and Wildlife Service,
Division of Environmental Quality. 12 pp.
Smith, A.L. 1979. Clams: A Growing Threat to Inplant Water Systems. Plant Engineering, June 14, 1979.
Smith, D.G. (ed.). 2001. Pennak’s Freshwater Invertebrates of the United States. J. Wiley and Sons, NY. 648
pp.
Smith, D.G. 2000. The Systematics and Distribution of the Margaritiferidae. In G. Bauer and K. Wachtler,
eds., Evolution of the Freshwater Mussels-Unionidae. Ecological Studies 145: 33-49. Springer, Berlin.
Soll, J., J.A. Hall, R. Pabst, and C. Soper, eds. 1999. Biodiversity Inventory and Analysis of the Hanford Site
– Final Report 1994–1999. The Nature Conservancy of Washington, Seattle, WA. 179 pp.
Stevens, R.A. 2000. Freshwater Mussel Shell Middens and the Nutritional Value of Margaritifera falcata on
the Upper Wenatchee River. Unpublished MS Thesis, Eastern Washington University, Cheney, WA, 103 pp.
Stewart, K.W. and B.P. Stark. 1993. Nymphs of North American Stonefly Genera (Plecoptera). University of
North Texas Press, Denton, TX. 460 pp.
Stober, Q.J. 1972. Distribution and age of Margaritifera margaritifera (L.) in a Madison River (Montana,
USA) mussel bed. Malacologia 11: 343-350.
Stock, A.L. 1996. Habitat and Population Characteristics of the Freshwater Mussel Margaritifera falcata in
Nason Creek, Washington. Unpublished MS Thesis, Evergreen State College, Olympia, WA.
Strenge, D.L. and R.S. Zack. 2003. Notes on the biology of Syntaxis formosa (Hulst) (Lepidoptera:
Geometridae) in south central Washington state. Proceedings of the Entomological Society of Washington
105: 781-782.
Strenge, D.L. Pacific Northwest National Laboratory, Richland, WA.
Svejcar, T. 1999. Coordinated weed management planning. In R.S. Shelley and J.K. Petroff, eds., Biology and
Management of Noxious Rangeland Weeds. Oregon State University Press, Corvallis, OR. pp. 57-68.
Taylor, D.W. 1988. Aspects of freshwater mollusc ecological biogeography. Palaeogeography,
Palaeoclimatology, Palaeoecology 62:511-576.
Taylor, D.W. 1981. Freshwater mollusks of California: A distributional checklist. California Fish and Game
67:140-163.
Taylor, D.W. 1975. Index and Bibliography of Late Cenozoic Freshwater Mollusca of Western North
America, Claude W. Hubbard Memorial Volume 1. Museum of Paleontology, University of Michigan, No.
10:1-384.
TCWPP (Teton County Weed and Pest Program). 2003. Land Values and Noxious Weeds. Teton County
Weed and Pest Program, Jackson, WY. http://www.tcweed.org/realtors.htm
TNC (The Nature Conservancy). 2003. Wildland Invasive Species Program. Available at:
http://tncweeds.ucdavis.edu/esadocs.html
Toy, K.A. 1998. Growth, reproduction and habitat preference of the freshwater mussel Margaritifera
Margaritifera falcata in western Washington. Unpublished MS Thesis, University of Washington, Seattle,
WA. 84 pp.
Tu, M. The Nature Conservancy Wildland Invasive Species Program, Portland, OR.

REFERENCES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
146
Tu, M. and B. Meyers-Rice. 2002. Site Weed Management Plan Template. The Nature Conservancy Wildland
Invasive Species Program. Available at: http://tncweeds.ucdavis.edu/index.html
USFS (United States Forest Service). 2001. Fire Effects: Bromus tectorum. United States Forest Service, Fire
Effects Information System. Available at:
http://www.fs.fed.us/database/feis/plants/graminoid/brotec/fire_effects.html
USFWS and CBSG (U.S. Fish and Wildlife Service and the Conservation Breeding Specialist Group). 2003.
Hanford Reach National Monument Planning Workshop II. U.S. Fish and Wildlife Service and the
Conservation Breeding Specialist Group (SSC/IUCN). Richland, WA.
USFWS and CBSG (U.S. Fish and Wildlife Service and the Conservation Breeding Specialist Group). 2002.
Hanford Reach National Monument Planning Workshop I. U.S. Fish and Wildlife Service and the
Conservation Breeding Specialist Group (SSC/IUCN). Richland, WA.
Van der Schalie, H. 1970. Hermaphroditism among North American freshwater mussels Malacologia
19(1):93-112.
Vannote, R.L. and G.W. Minshall. 1982. Fluvial processes and local lithology controlling abundance,
structure, and composition of mussel beds. Proceedings of the National Academy of Science 79:4103-4107.
Vaughn, C.C. and C.M. Taylor. 1999. Impoundments and the decline of freshwater mussels: A case study of
an extinction gradient. Conservation Biology 13:912-920.
Von Reis, J. Biology Instructor, Math and Science Division, Columbia Basin College, Pasco, WA.
Walker, B. 1910. The Distribution of Margaritana Margaritifera (LINN.) in North America. Proceedings of
the Malacological Society of London. 9:125-145.
Weiser, C. 1997. Economic Effects on Invasive Weeds on Land Values (from an Agricultural Banker's
Standpoint). In K.O. Britton, ed., Exotic Pests of Eastern Forests: Conference Proceedings, April 8-10, 1997.
USDA Forest Service and Tennessee Exotic Pest Plant Council. Nashville, TN.
Whisenant S.G. 1990. Changing fire frequencies on Idaho’s Snake River Plains: ecological and management
implications. In E.D. MacArthur, E.M. Romney, S.D. Smith, and P.T. Tueller (eds.), Proceedings –
Symposium on Cheatgrass Invasion, Shrub Die-off, and Other Aspects of Shrub Biology and Management.
General Technical Report INT-GTR-276. U.S. Dept. of Agriculture, Forest Service, Intermountain Research
Station. Pp. 1-7.
Wiggins, G.B. 1996. Larvae of the North American Caddisfly Genera (Trichoptera). University of Toronto
Press, Toronto, Canada, 457 pp.
Wilderman, D.L. 1994. Plant communities of the Fitzner/Eberhardt Arid Lands Ecology Reserve and the
North Slope of the Hanford Site: Findings of the 1994 inventory. Unpublished report on file at The Nature
Conservancy of Washington, Seattle, Washington.
Wilderman, D. Natural Areas Ecologist. Washington Department of Natural Resources, Natural Areas
Program. Ellensburg, WA.
Williams, J.D. 1993. Conservation Status of Freshwater Mussels: Families Margaritiferidae and Unionidae.
Journal of Shellfish Research 16(1): 327.
WNHP (Washington Natural Heritage Program). 2003. State of Washington Natural Heritage Plan 2003.
Washington Department of Natural Resources, Natural Heritage Program, Olympia, WA. Available online at:
http://www.wa.gov/dnr/nhp/refdesk/plan
WNHP (Washington Natural Heritage Program). 2000. Field Guide to Washington’s Rare Plants. Washington
Department of Natural Resources Natural Heritage Program, Olympia, WA., and U.S. Bureau of Land
Management.

REFERENCES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
147
WNHP (Washington Natural Heritage Program). 1999. State of Washington Natural Heritage Plan 1999.
Washington Department of Natural Resources, Natural Heritage Program, Olympia, WA.
WNHP (Washington Natural Heritage Program). 1997. Endangered, Threatened and Sensitive Vascular
Plants of Washington – with Working Lists of Non-Vascular Species. Washington Department of Natural
Resources, Natural Heritage Program, Olympia, WA.
WPPSS (Washington Public Power Supply System). 1986. Operational Ecological Monitoring Report for
Nuclear Plant 2, 1986 Annual Report. Washington Public Power Supply System, Environmental Programs
Department. Richland, WA.
WPPSS (Washington Public Power Supply System). 1985. Operational Ecological Monitoring Program for
Nuclear Plant 2, 1985 Annual Report. Washington Public Power Supply System, Environmental Programs
Department. Richland, WA .
WPPSS (Washington Public Power Supply System). 1984. Operational Ecological Monitoring Program for
Nuclear Plant 2, 1984 Annual Report. Washington Public Power Supply System, Environmental Programs
Department. Richland, WA.
WPPSS (Washington Public Power Supply System). 1977. Environmental Report, WPPSS Nuclear Project
No.2. Washington Public Power Supply System, Operating License Stage Docket No. 50-397, Richland, WA.
Wolf, E.G. 1976. Characterization of the Benthos Community. In, Final Report on Aquatic Ecological Studies
Conducted at the Hanford Generating Project, prepared by Pacific Northwest Laboratories for United
Engineers and Constructors, Inc. For Washington Public Power Supply System under contract No.
2311201335, Richland, WA.
Wolf, E.G. and C.E. Cushing. 1972. Productivity of Rattlesnake Springs. In Pacific Northwest Laboratory
Annual Report 1971, BNWL-1650 PT2, Vol.1 Life Sciences, Part 2 Ecological Sciences. Pacific Northwest
Laboratory, Richland, WA.
Young, J.A., and R.A. Evans. 1985. Demography of Bromus tectorum in Artemisia communities. Pp. 489-502
in White, J. (ed.), The Population Structure of Vegetation. Der Junk, Dordrecht.
Young, J.A., and R.A. Evans. 1978. Population dynamics after wildfires in sagebrush grasslands. Journal of
Range Management 31: 283-289.
Youtie, B. 1997. Weed control as the first step in protecting and restoring native plant communities on
Northeast Oregon natural areas. In T.N. Kaye, A. Liston, R.M. Love, D.L. Luoma, R.J. Meinke, and M.V.
Wilson, eds. Conservation and Management of Native Plants and Fungi. Native Plant Society of Oregon,
Corvallis. Pp 78-82.
Zack, R. S. 1998. Shore flies (Diptera: Ephydridae) of the Hanford Site, Washington. Northwest Science 72:
127-141.
Zack, R.S. Professor, Department of Entomology; Curator, M.T. James Entomological Collection.
Washington State University, Pullman, WA. Zack, R.S. and C.N. Looney. 2001. A new record of Cononotus
lanchesteri Van Dyke (Coleoptera: Pyrochroidae: Agnathinae) in Washington state with notes on habitat.
Coleopterists Bulletin 55: 67-69.
Zack, R.S. and C.N. Looney. In preparation. Notes on Paruroctonus boreus (Girard) (Scorpionida,
Vejovidae) in central Washington.
Zack, R.S., C.N. Looney, M.E. Hitchcox, and J.P. Strange. 2001. First occurrence of Leptopodidae in
Washington state (Hemiptera: Heteroptera) with notes on habitat. Pan-Pacific Entomologist 77: 47-50.
Zack, R.S., N.D. Penny, J.B. Johnson, and D.L. Strenge. 1998. Raphidioptera and Neuroptera from the
Hanford Site of southcentral Washington state. Pan-Pacific Entomologist 74: 203-209.

REFERENCES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
148
Zack, R.S., D.L. Strenge, and P.J. Landolt. 2003. Biological Diversity Study of Terrestrial Arthropods of
Selected Sites on the Hanford Reach National Monument. Report to The Nature Conservancy, Seattle, WA.
Zamora, D.L., and D.C. Thill. 1999. Early detection and eradication of new weed infestations. In R.S. Shelley
and J.K. Petroff, eds., Biology and Management of Noxious Rangeland Weeds. Oregon State University
Press, Corvallis, OR. pp. 73-84.
Zander, R.H. 1993. Genera of the Pottiaceae: Mosses of Harsh Environments. Bulletin of the Buffalo Society
of Natural Sciences, Vol. 32, Buffalo. 324 pp.

REFERENCES
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
149

Appendices

BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
152
Appendix A – Biodiversity Studies Contributors and Personnel
Project Coordinator and Editor
James R. Evans, The Nature Conservancy, Seattle, WA
Associate Editors
Marita P. Lih, The Nature Conservancy, Richland, WA
Peter W. Dunwiddie, The Nature Conservancy, Seattle, WA
Plant Community Mapping
Debra Salstrom, Richard Easterly
Salstrom & Easterly Eco-logic (SEE) Botanical Consultants
Tenino, WA
Rare Plants
Florence E. Caplow, Rare Plant Ecologist
Washington Department of Natural Resources, Natural Heritage Program
Olympia, WA
Microbiotic Crusts
Terry T. McIntosh, Biospherics Inc., Vancouver, British Columbia, Canada
Aquatic Invertebrates
Robert L. Newell, Polson, MT
Terrestrial Invertebrates
Richard S. Zack, Washington State University, Pullman, WA
Dennis L. Strenge, Pacific Northwest National Laboratory, Richland, WA
Peter J. Landolt, U.S. Department of Agriculture, Yakima Research Laboratory, Wapato, WA
Invasive Plant Species
James R. Evans, The Nature Conservancy, Seattle, WA
John J. Nugent, The Nature Conservancy, Seattle, WA
Jennifer K. Meisel, U.S. Fish and Wildlife Service, Hanford Reach National Monument, Richland, WA

APPENDIX A – BIODIVERSITY STUDIES CONTRIBUTORS AND PERSONNEL
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
153

BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
154
Appendix B – Acknowledgements
The following individuals made important contributions to this work.
Plant Community Mapping
Janelle Downs, Pacific Northwest National Laboratory
Rare Plants
Pam Camp, U.S. Bureau of Land Management, Spokane, WA
Mark Darrach, Poulsbo, WA
Peter Dunwiddie, The Nature Conservancy, Seattle, WA
Steve Farone, Washington Natural Heritage Program, Olympia, WA
Eliza Habegger, The Nature Conservancy, Seattle, WA
Kevin Kane, U.S. Bureau of Land Management, Spokane, WA
Douglas Reynolds, Rainshadow Nursery, Ellensberg, WA
Microbiotic Crusts
Gary Bradfield, Department of Botany, University of British Columbia, Vancouver, British Columbia,
Canada
Daniel Chan, Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
Ryan Clark, Richland, WA
Analyn Clark, Richland, WA
Janelle Downs, Pacific Northwest National Laboratory, Richland, WA
Martin Edwards, Stolo First Nations, Hope, British Columbia, Canada
Tony Glass, Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
Trevor Goward, Department of Botany, University of British Columbia, Vancouver, British Columbia,
Canada
Bruce McCune, Oregon State University, Corvallis, OR
Jeanne Ponzetti, Ellensberg, WA
Jennifer von Reis, Columbia Basin College, Pasco, WA
Tessa Richardson, Department of Botany, University of British Columbia, Vancouver, British Columbia,
Canada
Christine Weldrick, Department of Botany, University of British Columbia, Vancouver, British Columbia,
Canada

APPENDIX B – ACKNOWLEDGEMENTS
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
155
Aquatic Macroinvertebrates
Dennis Dauble, Pacific Northwest National Laboratory, Richland, WA
James Hansen, USDA Yakima Research Laboratory, Wapato, WA
Betty Hodges, Washington Public Power Supply System, Richland, WA
Duane Neitzel, Pacific Northwest National Laboratory, Richland, WA
Lee Rogers, Washington State University Tri-Cities, Richland, WA
Dennis L. Strenge, Pacific Northwest National Laboratory, Richland, WA
Invasive Plant Species Inventory and Management
Steve Buttrick, The Nature Conservancy, Portland, OR
A. Ray Johnson, Hanford Integrated Biological Control Program, FLUOR Hanford, Richland, WA
Sam Johnson, U.S. Fish and Wildlife Service, Region 1, Vancouver, WA
Barry Lavine, The Nature Conservancy, Portland, OR
Robert Leonard, The Nature Conservancy, Wenatchee, WA
Heidi Newsome, U.S. Fish and Wildlife Service, Hanford Reach National Monument, Richland, WA
Juan Rodriguez, Hanford Integrated Biological Control Program, Duratek, Inc., Richland, WA
Richard Roos, Hanford Integrated Biological Control Program, Duratek, Inc., Richland, WA
Dan Salzer, The Nature Conservancy, Portland, OR
Mandy Tu, The Nature Conservancy Wildland Invasive Species Program, Portland, OR
David Wilderman, Natural Areas Program, Washington Department of Natural Resources, Ellensburg, WA
GIS Support
Mark Goerring, The Nature Conservancy, Seattle, WA
Erin Stockenberg, U.S. Fish and Wildlife Service, Portland, OR
Cover Design
Claire Bronsen, The Nature Conservancy, Seattle, WA
Layout
Jan Lorey Hood, Editorial Services, Seattle, WA

APPENDIX B – ACKNOWLEDGEMENTS
BIODIVERSITY STUDIES OF THE HANFORD SITE—FINAL REPORT: 2002–2003
156
Collaborators for Invertebrate Identifications
Aquatic Macroinvertebrates
Alyson Brigham, U.S. Geological Survey, Denver, CO (Lepidoptera)
Boris Kondratieff, Colorado State University, Fort Collins, CO (Ephemeroptera)
Dave Nunnallee, Issaquah, WA (Odonata)
Dennis Paulson, University of Puget Sound, Tacoma, WA (Odonata)
Dave Ruiter, Centennial, CO (Trichoptera)
William Peters, Florida A & M University, Tallahassee, FL (Ephemeroptera)
William Shephard, Colorado State University, Fort Collins, CO (Coleoptera)
Curt Schmude, University of Wisconsin-Madison, Madison, WI (Coleoptera)
Terrestrial Invertebrates
Lars Crabo, Bellingham, WA (Noctuidae)
Robert Gordon, Northern Plains Entomology, Willow City, ND (Scarabaeidae)
Ronald W. Hodges, Eugene, OR (Lepidoptera - micromoths)
Jean-Francois Landry, Canadian National Collection of Insects, Ottawa, Ontario, Canada (Lepidoptera -
micromoths)
Rowland M. Shelley, North Carolina State Museum of Natural Sciences, Raleigh, NC (Diplopoda, Chilopoda)
Cover Photographs
Background: Jim Evans
Yellow starthistle: The Nature Conservancy
Western pearl mussel: Robert Newell
Gelechiid moth: Richard Zack
Biological soil crust: Terry McIntosh
Needle-and-thread – Sandberg’s bluegrass plant community: Richard Easterly and Debra Salstrom
White Bluffs bladderpod: Jonathan Soll

Spokane
Seattle
Portland
Yakima Ridge
Umtanum Ridge
Rattlesnake Mountain
Gable Mountain
Gable Butte
Saddle Mountains
Hwy. 240
Hwy. 24
Hwy. 243
Hwy. 24
400400
200200
600600
1106.1 m
400400
600600
821.7 m
200200
200200
200200
200200
White Bluffs
200200
400400
200200
600600
600600
White Bluffs
WB10 Ponds
Saddle Mou ntain Lake
Columbia R iver
Yakima Ri ver
River Corridor
Unit
McGee Ranch/
Riverlands
Unit
Central Hanford
(Department of Energy)
Fitzner/Eberhardt
Arid Lands Ecology
Reserve Unit
Saddle Mountain
Unit Wahluke
Unit
DOE
Borrow Are a
Vernita Bridge
Unit
Columbia R iver
0 5 10 15 20Kilometers
Legend
Contour Interval 100 Meters
Hanford Reach National Monument Boundary
Management Unit Boundaries
Central Hanford Boundary
Roads
Open Water
Fig. 1.1. The Hanford Site, including Central Hanford and the Hanford Reach National
Monument.

Columbia River
Hwy. 243
Hwy. 24
Hwy. 240
Fig. 2.1. Vegetation of the McGee Ranch-Riverlands Unit, Hanford Reach National Monument,
2002.
0 0.5 1 1.5 2Kilometers
Legend
Needle-and-Thread
Sandberg's Bluegrass
Sandberg's Bluegrass/Cheatgrass
Cheatgrass
Crested Wheatgrass
FacilitiesBluebunch Wheatgrass
Winterfat/Needle-and-Thread - Sandberg's Bluegrass
Winterfat/Bluebunch Wheatgrass
Purple Sage/Bluebunch Wheatgrass
Stiff Sagebrush/Sandberg's Bluegrass
Stiff Sagebrush/Bluebunch WheatgrassBig Sagebrush/Bluebunch Wheatgrass
Big Sagebrush/Sandberg's Bluegrass
Big Sagebrush/Needle-and-Thread
Big Sagebrush - Stiff Sagebrush/Bluebunch Wheatgrass
Big Sagebrush/Great Basin Wildrye
Big Sagebrush/Alkali Saltgrass
Powerlines
Secondary Roads
Primary Roads
Unit Boundary
Monument Boundary
Open Water

Columbia River
Hwy. 243
Hwy. 24
Hwy. 240
Fig. 2.2. Proposed Natural Heritage Element Occurrences on the McGee Ranch-Riverlands Unit,
Hanford Reach National Monument. See Table 2.2 for estimated areas for each element occurrence.
0 0.5 1 1.5 2Kilometers
Legend
Unit Boundary
Open Water
Monument Boundary
Stiff Sagebrush/Sandberg's Bluegrass
Secondary Roads
Powerlines
Primary RoadsBig Sagebrush - Spiny Hopsage/Sandberg's Bluegrass
Winterfat/Needle-and-Thread - Sandberg's Bluegrass
Big Sagebrush/Needle-and-Thread
Big Sagebrush/Bluebunch Wheatgrass

Yakima Ridge
Umtanum Ridge
Rattlesnake Mountain
Gable Mountain
Gable Butte
Saddle Mountains
Hwy. 240
Hwy. 24
Hwy. 243
Hwy. 24
400400
200200
600600
400400
200200
200200
200200
200200
White Bluffs
200200
400400
600600
600600
White Bluffs
WB10 Ponds
Saddle Mou ntain Lake
Columbia R iver
Yakima Ri ver
River Corridor
Unit
McGee Ranch/
Riverlands
Unit
Central Hanford
(Department of Energy)
Fitzner/Eberhardt
Arid Lands Ecology
Reserve Unit
Saddle Mountain
Unit Wahluke
Unit
DOE
Borrow Are a
Vernita Bridge
Unit
Columbia R iver
Fig. 3.1. Locations of microbiotic crust community sampling sites, Hanford Reach National
Monument, 2002-2003.
Legend
Management Unit Boundaries
Central Hanford Boundary
Roads
Open Water
Contour Interval 100 Meters
Microbiotic Crust Community Sampling Sites
Hanford Reach National Monument Boundary
0 5 10 15 20Kilometers
12
6
7
9
10
11
12
8
13
3 & 4
14
5
15

Yakima Ridge
Umtanum Ridge
Rattlesnake Mountain
Gable Mountain
Gable Butte
Saddle Mountains
Hwy. 240
Hwy. 24
Hwy. 243
Hwy. 24
400400
200200
600600
400400
200200
200200
200200
200200
White Bluffs
200200
400400
600600
600600
White Bluffs
WB10 Ponds
Saddle Mou ntain Lake
Columbia R iver
Yakima Ri ver
River Corridor
Unit
McGee Ranch/
Riverlands
Unit
Central Hanford
(Department of Energy)
Fitzner/Eberhardt
Arid Lands Ecology
Reserve Unit
Saddle Mountain
Unit Wahluke
Unit
DOE
Borrow Are a
Vernita Bridge
Unit
Columbia R iver
Fig. 4.1. Range of Columbia yellowcress (Rorippa columbiae) on the Hanford Reach.
0 5 10 15 20Kilometers
Legend
Management Unit Boundaries
Central Hanford Boundary
Roads
Open Water
Contour Interval 100 Meters
Range of Rorippa columbiae
Hanford Reach National Monument Boundary

Energy NorthwestEnergy Northwest
Homestead
Island
Columbia River
River Corridor
Unit
Wahluke
Unit
Central Hanford
(Department of Energy)
Fig. 4.2. Location of BLM monitoring transects established in 1991 for Columbia yellowcress
(Rorippa columbiae).
Ringold Fish
Rearing
Facility
260260
200200
200200
260260
160160
200200
260260
120120
260260
140140
120120
012345Kilometers
Legend
Contour Interval 20 Meters
Facility Boundary
Open Water
PowerlinesLocation of BLM Monitoring Transects
Management Unit Boundaries
Roads
Streams, Canals, and Shorelines

Yakima Ridge
Umtanum Ridge
Rattlesnake Mountain
Gable Mountain
Gable Butte
Saddle Mountains
Hwy. 240
Hwy. 24
Hwy. 243
Hwy. 24
400400
200200
600600
400400
200200
200200
200200
200200
White Bluffs
200200
400400
600600
600600
White Bluffs
WB10 Ponds
Saddle Mou ntain Lake
Columbia R iver
Yakima Ri ver
River Corridor
Unit
McGee Ranch/
Riverlands
Unit
Central Hanford
(Department of Energy)
Fitzner/Eberhardt
Arid Lands Ecology
Reserve Unit
Saddle Mountain
Unit Wahluke
Unit
DOE
Borrow Are a
Vernita Bridge
Unit
Columbia R iver
Fig. 10.1. Search areas for invasive plant species, Hanford Reach National Monument,
2002-2003.
0 5 10 15 20Kilometers
Legend
Management Unit Boundaries
Central Hanford Boundary
Contour Interval 100 Meters
Hanford Reach National Monument Boundary
Search Areas for Invasive Plant Species Roads
Open Water

Yakima Ridge
Umtanum Ridge
Rattlesnake Mountain
Gable Mountain
Gable Butte
Saddle Mountains
Hwy. 240
Hwy. 24
Hwy. 243
Hwy. 24
400400
200200
600600
400400
200200
200200
200200
200200
White Bluffs
200200
400400
600600
600600
White Bluffs
WB10 Ponds
Saddle Mou ntain Lake
Columbia R iver
Yakima Ri ver
River Corridor
Unit
McGee Ranch/
Riverlands
Unit
Central Hanford
(Department of Energy)
Fitzner/Eberhardt
Arid Lands Ecology
Reserve Unit
Saddle Mountain
Unit Wahluke
Unit
DOE
Borrow Are a
Vernita Bridge
Unit
Columbia R iver
Fig. 10.2. Areas infested by invasive plant species, Hanford Reach National Monument,
2002-2003.
0 5 10 15 20Kilometers
Legend
Management Unit Boundaries
Central Hanford Boundary
Contour Interval 100 Meters
Hanford Reach National Monument Boundary
Areas Infested by Invasive Plant Species Roads
Open Water