John C. Tappeiner, II

Oregon State University | OSU · Department of Forest Engineering, Resources and Management

Saplings of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco var. menziesii) were grown with and without competition from tanoak (Lithocarpusdensiflorus (Hook. & Arn.) Rehd.) at two forest sites in southwestern Oregon. Competition reduced the following morphological parameters on Douglas-fir shoots: number and size of buds; lengths of shoots, inter...

A mathematical index representing relative growth potential of an individual tree is developed as a function of crown-surface area exposed to sunlight and distance from the crown to d.b.h. The index measures the relative competitiveness of an individual tree rather than the relative competitive pressure being exerted on an individual tree by surrou...

To provide methods for predicting site occupancy by sprouting understory hardwoods after conifer harvest, data from 142 tanoak (Lithocarpusdensiflorus (Hook. and Arn.) Rehd.) and 165 Pacific madrone (Arbutusmenziesii Pursh) sprout clumps, 1 to 6 years old, were used to develop equations for predicting leaf area and aboveground biomass. Crown cross-...

The stocking, age, and growth rates of tanoak (Lithocarpusdensiflorus [Hook and Arn.] Rehd.) were studied in the understory of 13 Douglas-fir (Pseudotsugamenziesii [Mirb] Franco) and mixed conifer stands, 53–240 years old, on a range of sites in Oregon and California. The understory was uneven in both age and size in all stands. Tanoak <2.0 cm diam...

Shrubs and hardwoods in five plantations of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) in southwestern Oregon were treated to obtain four or five levels of competition; cover ranged from 0 (complete control) to 100% (no treatment). On four of the five plantations, Douglas-fir seedlings significantly increased bud production on the leader in...

Survival, age and height distributions, and stocking of bigleaf maple (Acermacrophyllum Pursh) seedlings were studied in 1- to 250-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stands in western Oregon to identify the stages in stand development in which bigleaf maple is most likely to establish successfully from seed. Maple seedling e...

Soil chemical and physical properties, forest floor weights, nutrient content and turnover rates, and litter fall weights and nutrient content under bigleaf maple (Acermacrophyllum Pursh) and Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco var. menziesii) were compared on five sites on the eastern margin of the Oregon Coast Range. Litter fall weig...

Seedlings of western hemlock (Tsugaheterophylla (Raf.) Sarg.) and early huckleberry (Vacciniumovalifolium Smith) were studied for 5 years following windthrow in a dense 45-year-old forest to better understand the contrasting reproductive and growth stategies of woody shrubs and trees to small natural disturbances in temperate rain forest environmen...

Red alder (Alnusrubra Bong.) seed showing strong phytochrome activity in the laboratory was tested to determine whether the phytochrome effect could influence germination under light conditions experienced in the field. Seeds in sealed Petri dishes were placed beneath three types of overstory cover (clearcut (no overstory); Douglas-fir (Pseudotsuga...

To determine how Vaccinium alaskaense, Cornus canadensis, Coptis asplenifolia, Tiarella trifoliata, and Rubus pedatus invade and maintain themselves in conifer forests, we conducted experiments on seed germination and seedling survival and examined clonal development in old-growth, young-growth, and 4- to 6-year-old stands. Seed of all species germ...

The life-history requirements of northern spotted owls (Strix occidentalis caurina), a federally listed “threatened” species, are associated with late-successional habitats. Nesting sites are an important habitat requirement for spotted owls. We used an individual-tree, distance-independent growth model to explore a range of management scenarios fo...

Diameter growth and age data collected from stumps of 505 recently cut old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees at 28 sample locations in western Oregon (U.S.A.) indicated that rapid early and sustained growth of old Douglas-fir trees were extremely important in terms of attaining large diameters at ages 100-300 years. Th...

Annual sprouting of aerial stems and ramets enables populations of salmonberry (Rubus spectabilis Pursh), salal (Gaultheria shallon Pursh), and probably other forest shrubs to maintain dense covers (> 20 000 stems/ha). We studied annual stem production of salmonberry on cut (all stems cut within 15 cm of the ground) and uncut (stems were not treate...

Annual sprouting of aerial stems and ramets enables populations of salmonberry (Rubus spectabilis Pursh), salal (Gaultheria shallon Pursh), and probably other forest shrubs to maintain dense covers (>20 000 stems/ha). We studied annual stem production of salmonberry on cut (all stems cut within 15 cm of the ground) and uncut (stems were not treated...

The effect of different densities of varnishleaf ceanothus (Ceanothus velutinus var. laevigatus) and herbaceous vegetation control on stem diameter, height, and volume of plantation Douglas-fir (Pseudotsuga menziesii vat. menziesii) seedlings was examined during the 10 yr following planting. Initial densities of ceanothus ranged between 0 and 15,00...

In response to public dissatisfaction with forest management methods, we initiated the College of Forestry Integrated Research Project (CFIRP) to test alternative silvicultural systems in Douglas-fir (Pseudotsuga menziesii stands in western Oregon. We compared costs and biological and human responses among a control and three replicated silvicultur...

Silvicultural alternatives to clear-cutting have been suggested to promote development, retention, or creation of late-successional features such as large trees, multilayered canopies, snags, and logs. We assessed bird response to three silvicultural alternatives to clear-cutting that retained structural features found in old Douglas-fir (Pseudotsu...

Seedling regeneration and morphology of Oregon grape (Berberis nervosa Pursh) and salal (Gaultheria shallon Pursh) were studied in thinned and unthinned Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands in the central Coast Range, Oregon. Above- and below-ground growth of both species were significantly and negatively correlated with stand...

Canopy architectures of five structurally complex forest stands and three structurally simple forest stands in southwest Oregon and the Willamette Valley, Oregon, were evaluated and quantified through crown area profiles. Mixed conifer and mixed conifer-hardwood stands across a range of sites were sampled for crown widths and heights. Crown width a...

A large area of Pacific Coast forests is characterized by shallow soil, with negligible rainfall in the growing season. This study explores water-seeking strategy on such a site. We studied availability of bedrock water and its effects on growth and ecophysiology of 11-yr-old planted Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) and sprouting...

Effects of forest disturbance and soil moisture levels on establishment of red alder (Alnus rubra Bong.) seedlings were studied at four sites representing a climatic moisture gradient within the central Coast Range of Oregon. On average, there was no difference in seedling emergence between recent clearcuts and second-growth forests, but emergence...

Vine maple (Acer circinatum Pursh.) clone development, expansion, and regeneration by seedling establishment were studied in 5-240 yr old managed and unmanaged Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands in coastal Oregon. Stem length, number of stems, and crown area were all significantly (P @< 0.01) related to stand age, and clone d...

Rhizome cuttings and seed of salal (Gaultheria shallon) were cultured in nursery beds at four light intensities (20, 50, and 70%, and full sunlight) created by various thicknesses of shade cloth. After each of two growing seasons, growth and morphological characteristics were compared among light intensities and between life stages. Under all light...

Branch diameter was measured in 29- and 38-yr-old western hemlock (Tsuga heterophylla) that had been precommercially thinned to spacings of 4.0 to 21.8 ft at about the time of initial crown closure (age 11 and 12 yr). Branch diameter increased with spacing, but did not exceed 2 in. even at the widest spacings. At the 40- to 60-yr rotations now plan...

Wood density of western hemlock (Tsugaheterophylla (Raf.) Sarg.) was determined by X-ray densitometry of strips from breast-height samples consisting of rings 20–24 from the pith. Ring parameters were averaged over the 5 years for each strip. Wood density was negatively correlated with radial growth rate. Average wood density dropped from 0.47 to 0...

Plant water potential, leaf conductance, and photosynthesis of saplings of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) were monitored monthly in 1986 through 1988. The objective was to describe influences of microclimate (light, soil water, temperature, and relative humidity) associated with young stands of tanoak (Lithocarpus densiflorus [H...

Regeneration of salal (Gaultheria shallon Pursh.) by seedling establishment and vegetative expansion was examined under various forest conditions in the central Coast Range of Oregon. Size and expansion rate of individual clonal fragments were negatively correlated with overstory stand density (p ≤ 0.039). As overstory basal area increased from 25...

Crown size and stem diameters were measured on a total of 908 sprout clumps of tanoak (Lithocarpus densiflorus), Pacific madrone (Arbutus menziesii), and giant chinkapin (Castanopsis chrysophylla). The clumps, age 1 to 16 years, were located at 23 sites in southwestern Oregon and 20 sites in northwestern California. Regression equations were develo...

To understand how populations of salmonberry (Rubus spectabilis) persist in common forest stand types, we studied the above- and belowground structure of salmonberry clones and populations in upland alder and conifer stands in riparian stands, and in 2-yr-old and 13- to 18-yr-old clearcuts in the central Oregon Coast Range. On undisturbed sites ind...

Bigleaf maple is a common hardwood in western Oregon and Washington. Stored seeds from this species are generally believed to lose viability within a few weeks. In this study, two experiments were conducted with seeds collected in 1986 and 1987 in the Oregon Coast Range west of Corvallis, OR. Seeds collected in 1986 had a field moisture content (pe...

We studied the development of Pacific madrone (Arbutus menziesii) sprout clumps of various initial densities and their effect on Douglas-fir (Pseudotsuga menziesii) seedling growth and understory vegetation. Five years after density treatments, average leaf area index (LAI) of 9-year-old madrone sprouts ranged from 3.6-1.0 m²/m² and total abovegrou...

To help foresters assess site occupancy of seed-established stands of varnishleaf (Ceanothus velutinus var. laevigatus) deerbrush (Ceanothus integerrimus), and whiteleaf manzanita (Arctostaphylos viscida), we developed equations for estimating their aboveground biomass and leaf area. From 9 to 14 pure stands from 2 to 20 years old were selected for...

Advances in forest practices during the past few decades have been made in the midst of public debate over the role of forestry. It is time to assess the state of the art of silviculture and to project its evolution for the next 30 years - to reinforce the use of sound practices now employed and to shed outdated concepts and practices. To a large e...

Roots of a 21-year-old aspen (Populus tremuloides Michx.) in a dense 25-year-old red pine (Pinus resinosa Ait.) plantation and those of a 60-year-old aspen in a natural red pine stand of the same age were studied to determine if aspen can maintain root systems capable of suckering after red pine removal. The roots of the younger aspen apparently ha...

The role of hazel shrub and herbaceous undergrowth layers in nutrient cycling was studied in two red pine (Pinus resinosa Ait.) and two paper birch (Betula papyrifera Marsh.) stands on similar soil types in northern Minnesota. The annual litterfall produced by these undergrowths and by the overstory was sampled at 15 points in each stand as was the...

Studies in hazel undergrowths in five Minnesota pine stands provided techniques for estimating total hazel biomass and its three components (leaves, aerial stems, underground parts). Regression equations were developed for estimating total biomass and the three components based on measurements of aerial stem weight, aerial stem basal area, or numbe...

First- and 2nd-year survival and height growth of naturally regenerated white fir and douglas fir seedlings were studied in typical microenvironments on exposed slopes and ridge tops at an elevation of 1300 m in the Sierra Nevada of California. Microsites were described by measuring soil moisture at several depths and potential evaporation at 1st-y...

Invasion of red pine stands in northern Minnesota by beaked hazel occurred mainly by seeding, and dense undergrowths were formed by a coalescence of many individual clones (about 2,000/acre). In young undergrowths, where beaked hazel was becoming established, 25-43% of the individuals were in the seedling stage under 12 years old, and 72-92% of the...

Results of the Hoskins levels-of-growing-stock (LOGS) study in western Oregon are summarized and management implications discussed through the fifth and final planned treatment period. To age 40 thinnings in this low site I Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stand resulted in large increases in diameter growth with reductions in bas...

Shoot and needle length in the upper crown of 30- to 50-year-old cone-bearing Douglas-fir were reduced in years of cone production, whereas on nonbearing trees they were unchanged. Xylem ring width at breast height in cone-bearers was reduced in years of heavy cone crops but was apparently unchanged in years of light crops. Growth was reduced only...