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Fire Ecology: United States and Southern Canada
Journal of Applied Ecology
... The length of time required for grassland forage productivity to recover following fire is variable and can take several years (Erichsen-Arychuk et al. 2002), and is further subject to environmental conditions and ongoing grazing influences. In particular, above-normal precipitation following fire can lead to more rapid recovery of forage productivity on burned areas (Wright and Bailey 1982). Furthermore, cattle and wildlife prefer burned grasslands due to increased forage quality (Dufek et al. 2014), which could result in overgrazing. ...
... Soils in the region are predominately Orthic Brown Chernozems (Natural Regions Committee 2006). The historical fire frequency in the Northern Great Plains is estimated at 5 to 10 years (Wright and Bailey 1982). In recent history, affected pastures were grazed by cattle rotationally (spring, summer, or fall) or continuously through the growing season. ...
... Similar results of rapid recovery have been found in the mixed-grass Prairie of North Dakota, where defoliation did not impact post-fire wildfire recovery (Gates et al. 2017). Wheatgrass species, which dominated our study sites, are considered as resistant to fire because they have less flammable litter at plant bases and regrow from rhizomes (Wright and Bailey 1982). The lack of a significant interaction between wildfire and defoliation during years with below average precipitation demonstrates that long periods of post-fire rest may not be necessary for forage recovery in the mixed-grass Prairie. ...
Post-fire rangeland management recommends rest from grazing to allow forage regrowth and litter accumulation. In the first year after wildfire in the mixed-grass Prairie, we examined forage and litter mass responses to variable timing of defoliation in burned and non-burned areas. Total forage biomass did not differ between burned and non-burned areas by the second growing season. The July defoliation in both burned and non-burned areas reduced total forage biomass. Litter mass was decreased by wildfire and was further reduced by all defoliation treatments.
... In western North America, cattle, an introduced herbivore, and infrequent fire are nearly ubiquitous across the Artemisia (sagebrush) ecosystem. Fire is a periodic disturbance in this ecosystem with historical fire return intervals varying from over a century to around a quarter century in drier and more mesic Artemisia communities, respectively ( Wright and Bailey 1982 ;Mensing et al. 2006 of the Artemisia steppe, and these communities are generally less resilient to disturbance ( Davies et al. 2011 ;Chambers et al. 2014 ). Historically, fires shifted dominance from Artemisia to herbaceous vegetation and, as time since fire increased, Artemisia would redominate these sites until the next fire ( Wright and Bailey 1982 ). ...
... Fire is a periodic disturbance in this ecosystem with historical fire return intervals varying from over a century to around a quarter century in drier and more mesic Artemisia communities, respectively ( Wright and Bailey 1982 ;Mensing et al. 2006 of the Artemisia steppe, and these communities are generally less resilient to disturbance ( Davies et al. 2011 ;Chambers et al. 2014 ). Historically, fires shifted dominance from Artemisia to herbaceous vegetation and, as time since fire increased, Artemisia would redominate these sites until the next fire ( Wright and Bailey 1982 ). However, vegetation succession has been greatly modified by exotic annual grass invasion of some A. t. subsp. ...
... The wildfire season generally spans from July to mid to late September depending on interannual climate ( Davies and Nafus 2013 ; NIFC 2021 ). Fire occurrence was infrequent before European settlement for these Artemisia communities with fire return intervals estimated to be 50 −100 + yr ( Wright and Bailey 1982 ;Mensing et al. 2006 ). ...
Grazing and fire are both independently important drivers of plant community dynamics; however, their interactive effects may be even more influential. Little is known about prefire grazing effects on postfire plant community dynamics. We investigated the effects of dormant-season, moderate prefire grazing by cattle on postfire plant community response in the imperiled Artemisia (sagebrush) steppe. Treatments were moderately grazed or not grazed by cattle for 5 yr before fire. The first yr post fire, shrub density was 4 × greater in grazed areas, demonstrating fire-induced mortality was reduced with grazing. This further suggested that grazing reduced fire severity and postfire large bunchgrass biomass was greater in grazed compared with ungrazed areas. Biomass and abundance of the exotic annual grass, Bromus tectorum L., were substantially greater and plant diversity was lower in ungrazed compared with grazed areas post fire. Five years post fire, perennial herbaceous vegetation still dominated prefire-grazed areas, but ungrazed areas were dominated by B. tectorum, suggesting that a novel ecosystem state had developed. Substantial increases in B. tectorum are concerning because it prevents recruitment of native perennial plants and increases fire frequency, which would further decrease diversity and reinforce an exotic annual-dominated state. Lower diversity in ungrazed areas post fire is concerning because diversity can be important for plant community stability. The importance of livestock as ecological engineers through their influence on fire has largely been overlooked but is clearly substantial and needs to be integrated into conservation and management plans.
... Las especies toleran perturbaciones como el fuego debido a una característica evolutiva, como es la protección de un banco de yemas viable que produce rebrotes (Wright y Bailey 1982;Casillo et al. 2012;Clarke et al. 2012;Bravo et al. 2018). La habilidad para rebrotar brinda información sobre los procesos demográficos en las especies leñosas (Bond 2008). ...
... El fuego puede ser usado bajo condiciones de prescripción, con objetivos concretos , como es el manejo del estrato arbustivo. En la práctica del fuego prescripto se debe considerar el régimen natural de fuego de cada ecosistema y proceder bajo condiciones meteorológicas controladas (Wright y Bailey 1982). Casillo et al. (2012) encontraron que: a) el fuego tuvo un primer efecto depresor en la emergencia de gramíneas nativas en sabanas, (mismo sitio de estudio que esta tesis) pero luego de dos años el establecimiento de este grupo funcional se incrementó y b) el fuego redujo el establecimiento de las especies leñosas. ...
... Estos parámetros dan una idea de la severidad del fuego, a mayor tiempo de residencia del mismo, más severo es el efecto en la vegetación y en el suelo (Wright y Bailey 1982;Stoof et al. 2013). ...
El incremento de la biomasa aérea, cobertura y densidad de las especies leñosas, especialmente arbustivas, en detrimento de las gramíneas y eventualmente otros grupos funcionales, es un proceso muy común en ambientes subhúmedos a áridos. La coexistencia pastos-arbustos puede ser explicada mediante distintos mecanismos ecológicos, agrupados bajo dos grandes enfoques: competencia y demografía. Los mecanismos competitivos involucran entre otros, separación de nichos por exploración radical, competencia balanceada, relaciones de competencia y facilitación, mecanismos regenerativos, efecto almacenaje. El enfoque demográfico sugiere que los disturbios gobiernan la coexistencia pastos-arbustos a través del control sobre la demografía. El objetivo de este trabajo fue comprender los mecanismos ecológicos que regulan la coexistencia pastos-arbustos en el Chaco semiárido, mediante un estudio que contempla ambos enfoques. Los experimentos se realizaron en dos sitios ecológicos en la provincia de Santiago del Estero: alto, con un bosque de dos quebrachos y bajo, dominado por sabanas de Elionurus muticus. Para estudiar el mecanismo de separación de nichos por exploración radical vertical (Hipótesis de Walter) se desarrolló un estudio descriptivo de la distribución de raíces en el perfil del suelo. Además, se realizó un ensayo de remoción de especies para analizar el tipo de interacción que ocurre entre los grupos funcionales, con los tratamientos: a) remoción de arbustos, b) remoción de pastos y c) sin remoción (control) usando un Índice de Interacción. El efecto almacenaje fue analizado mediante el estudio de la emergencia y la habilidad para rebrotar de los arbustos en respuesta a la secuencia sinérgica de dos perturbaciones: mecánica y fuego. Los principales resultados fueron: a) el patrón de distribución radical encontrado responde parcialmente a la Hipótesis de Walter, ya que existe en ambos sitios ecológicos superposición de los sistemas radicales de pastos y arbustos en el perfil del suelo; b) en el bajo prevalecerían las relaciones de competencia, mientras que en el alto las relaciones neutrales y de facilitación; c) la emergencia de las plántulas varió en función del sitio, de la intensidad del fuego y del grupo funcional y d) la habilidad rebrotadora de los arbustos estuvo condicionada por la intensidad de las perturbaciones y por la especie. Esta tesis contribuye a comprender qué mecanismos ecológicos prevalecerían entre pastos y arbustos en los sitios de bosque y sabana del Chaco semiárido, y cómo las perturbaciones (tratamiento mecánico y fuego) influyen en los procesos regenerativos. Este conocimiento permitirá explicar a futuro los cambios en la estructura de las comunidades y en las funciones ecosistémicas, con el fin de generar recomendaciones de manejo más conservativas y sustentables.
... Fire, particularly during the breeding season, can be devastating to ground-nesting birds by destroying nests, eliminating nesting cover, and reducing insect food resources (Daubenmire 1968;Bendell 1974). In the long term, however, fire can be beneficial by increasing the diversity of habitat and wildlife, especially if it occurs outside the breeding season (Stoddard 1963;Wright and Bailey 1982;Driver 1987). In recent years, wildlife managers have used "prescribed burning" as a management tool to modify and diversify habitat, to reduce wildfire hazards by removal of fuel, to release nutrients and thereby improve new plant growth, and to remove accumulated material no longer palatable to grazers (Wright and Bailey 1982). ...
... In the long term, however, fire can be beneficial by increasing the diversity of habitat and wildlife, especially if it occurs outside the breeding season (Stoddard 1963;Wright and Bailey 1982;Driver 1987). In recent years, wildlife managers have used "prescribed burning" as a management tool to modify and diversify habitat, to reduce wildfire hazards by removal of fuel, to release nutrients and thereby improve new plant growth, and to remove accumulated material no longer palatable to grazers (Wright and Bailey 1982). ...
... Forests occupy a broad range of precipitation and temperature conditions in the Western States. In the warmest and driest coniferous forests-such as ponderosa pine (Pinus ponderosa) forests-trees and understory plants produce enough fine fuels to carry fires every few years, fire seasons are long, and tree and understory plant species are able to survive frequent, low-severity wildfires (Wright and Bailey 1982). Ignitions and fuel continuity were historically the primary constraints on fire frequency in these forests, and fires generally burned often enough to prevent fuels from accumulating to levels that would promote higher fire severities. ...
... At the opposite end of the annual precipitation gradient, high soil water availability in maritime forests promotes high forest productivity and fuel accumulations, but high fuel moisture limits fuel flammability and spatial continuity throughout much of the year (Agee 1993, Krawchuk andMoritz 2011, Wright andBailey 1982). Fire frequencies are typically very low in these forests (e.g., centuries between fires), but wildfire burn severity can be high if wildfires occur when fuels are dry. ...
... Fire is an important ecological driver that helped establish and maintain Great Plains grasslands, but has largely been suppressed and excluded following European settlement (Wright and Bailey, 1982;Axelrod, 1985;Anderson, 2006;Engle et al., 2008). The removal of fire as a natural disturbance, for which native grassland flora and fauna are adapted, has resulted in a loss of biodiversity, reduced structural heterogeneity within grasslands, and increased risk of larger and more frequent wildfire (Wright and Bailey, 1982;Collins and Barber, 1986;Fuhlendorf and Engle, 2001;Lindley et al., 2013;Twidwell et al., 2013). ...
... Fire is an important ecological driver that helped establish and maintain Great Plains grasslands, but has largely been suppressed and excluded following European settlement (Wright and Bailey, 1982;Axelrod, 1985;Anderson, 2006;Engle et al., 2008). The removal of fire as a natural disturbance, for which native grassland flora and fauna are adapted, has resulted in a loss of biodiversity, reduced structural heterogeneity within grasslands, and increased risk of larger and more frequent wildfire (Wright and Bailey, 1982;Collins and Barber, 1986;Fuhlendorf and Engle, 2001;Lindley et al., 2013;Twidwell et al., 2013). Recent wildfires within the Great Plains have increased in size and severity due to the effects of climate change, encroachment of woody vegetation, and the long-term practice of fire suppression and exclusion in the region which has altered the structure and amount of fuels on the landscape (Lindley et al., 2013(Lindley et al., , 2019Twidwell et al., 2013;Donovan et al., 2017Donovan et al., , 2020b. ...
While fire is a necessary ecological driver for grassland systems, Great Plains grasslands have undergone extensive land use change following European settlement (conversion, fragmentation, fire suppression, intensive grazing, etc.). Recent studies have documented the benefits of re-introducing fire to grasslands, but work has largely focused on small-scale, low-intensity fire, often at a pasture scale (i.e., prescribed fire). Over the last 30–40 years, the size and frequency of wildfires in the Great Plains has increased due to long-term fire suppression, woody encroachment, and climate change, resulting in megafires (wildfire >40,000 ha). While there is a wealth of information regarding effects of prescribed fire on Great Plains grasslands, knowledge of how large megafire events affect modern, fragmented working grasslands (i.e., grazed grasslands) is lacking and needed in the face of increasing megafire activity. To assess grassland response and recovery following a 2017 megafire (~254,000 ha), we compared vegetation characteristics pre- (2014–2015) and post-fire (2018–2019) in the mixed-grass prairie of Kansas, USA. We examined linkages between vegetation characteristics and a metric of burn severity (differenced normalized burn ratio [dNBR]) and evaluated megafire effects on limiting reproductive habitat for a declining grassland species, the lesser prairie-chicken (Tympanuchus pallidicinctus). One-year post-fire, we documented increased bare ground (+59%) and decreased visual obstruction (-39%), litter depth (-31%), and forb cover (-35%). Decreased visual obstruction and increased bare ground led to an 81% decrease of lesser prairie-chicken nest habitat in the first-year post-fire, but grassland structure, functional group cover, and available nest habitat largely recovered 2.5 years post-fire. Recovery to pre-fire conditions 2.5 years post-fire was primarily due to elevated growing season precipitation received in the years following the fire (>700 mm/year). Percent cover of grass (β = 0.38) and bare ground (β = -0.36) exhibited the strongest relationships with burn severity pre-fire, but overall grassland structure and functional group cover were not strongly influenced dNBR burn severity post-fire. While our results suggested that recovering grasslands were more homogenous due to the large size of megafire, working grasslands in the mixed-grass prairie appeared largely resilient to the effects of megafire.
... Study sites occurred on two ecological sites: Sandy Loam 10-12 PZ (R023XY213OR) and Droughty Loam 11-13 PZ (R023XY316OR) Ecological Sites ( NRCS 2013 ). Fire occurrence for these sagebrush steppe communities was infrequent before European settlement with fire return intervals estimated to be 50 −100 + yr ( Wright and Bailey 1982 ;Mensing et al. 2006 ). Study sites had no recent record of burning or any evidence of prior burning, suggesting that the sites had not experienced fire for at least + 75 yr. ...
... Increases in exotic annual grasses and annual forbs and a decline is biological soil crust with fire are concerning as they suggest that these communities may transition from native perennial dominance toward exotic annual dominance. Though fire was historically an important ecological event associated with transient shifts from shrub to native herbaceous vegetation dominance ( Wright and Bailey 1982 ), exotic annual grass invasion has supplanted native vegetation postfire succession and fundamentally altered the ecological role of fire in low resistant and resilient Wyoming big sagebrush communities. However, fire is still critical to limit conifer expansion in higher-elevation sagebrush communities that have a lower risk of exotic annual grass dominance ( Davies et al. 2019 ). ...
Exotic annual grass invasion is a pressing concern in sagebrush rangelands of the western United States. Overgrazing and fire have historically both been implicated in the rise of annual grasses, but experiments that compare the effect of grazing versus fire are lacking, particularly for contemporary grazing practices such as off-season (fall and winter) grazing. We compared 1) burned and ungrazed (burned), 2) off-season, moderately grazed and unburned (grazed), and 3) ungrazed and unburned (control) treatments at five Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis [Beetle & A. Young] S.L. Welsh) sites in southeastern Oregon for half a decade. Fire, but not off-season grazing, substantially increased exotic annual grass cover and abundance. Vegetation cover and density were generally similar between grazed and control areas. In contrast, at the end of the study exotic annual grass cover and density were over fourfold greater in burned areas. Exotic annual grass became the dominant plant group in burned areas, but not in grazed and control areas. Cover and density of annual forbs, predominately non-native species, were generally greater in the burned compared with grazed and control treatments. Fire also decreased soil biological crust cover and sagebrush cover and density compared with grazed and control treatments. This study provides strong evidence that fire is a threat to the sustainability of Wyoming big sagebrush communities at risk of exotic annual grass dominance, but that off-season, moderate grazing poses little risk. However, considering the spatial extent of our study was limited, further evaluations are needed across a larger geographic area. Given that off-season grazing can decrease the probability of fire, off-season grazing may be a valuable tool to reduce the risk of exotic annual grass dominance.
... Fire historically played a primary role as a disturbance factor in shrub ecosystems (Daubenmire 1968, Burkhardt and Tisdale 1976, Gruell 1985, Eddleman and Doescher 1999, Miller and Eddleman 2000. Nevertheless, shrubsteppe habitats can be affected by a variety of other factors including insects, rodents, climatic changes, grazing, and disease (Champlin and Winward 1982, Wright and Bailey 1982, Hironaka et al. 1983, Crane and Fisher 1986, Kauffman 1990, Young 1990, Peterson 1995, Tart 1996, Miller and Eddleman 2000, Paysen et al. 2000, Ryan 2000. Mule deer have evolved with fire that has impacted sagebrush stands with variable return intervals, depending on moisture regimes, topography, soils, and plant communities (Bunting et al. 1987). ...
... There are competing theories on how often fire historically burned these ecosystems (Winward 1991, Welch and Criddle 2003, Baker 2006. Some scientists believe presettlement fires may have occurred every 100 to 200 years in low sagebrush (Artemisia arbuscula) community types Evans 1981, Miller andRose 1999) and 30 to 110 years in Wyoming big sagebrush (Artemisia tridentata wyomingensis) community types (Young and Evans 1981, Winward 1991, Wright and Bailey 1982. In more mesic sagebrush types characterized by mountain big sagebrush (Artemisia tridentata vaseyana), fire return intervals have been reported to occur between 12 and 25 years (Houston 1973, Burkhardt and Tisdale 1976, Miller and Rose 1999. ...
Mule deer management guidelines for the Intermountain West Ecoregion are intended to be used by a broad spectrum of people involved and interested in mule deer habitat management and stewardship on public and private ownership.
... In the southern United States, fire played an indispensable role in the growth and development of the forest forage resource. Low-intensity surface fires set by lightning were responsible for the open, grassy understory of longleaf pine forests (Franklin, 1997;Wright & Bailey, 1982). Native Americans managed these natural forage resources by burning to sustain forage growth and guide animal movement (MacCleery, 1992;Robbins & Wolf, 1994). ...
... Prescribed burning proved useful in improving the nutritional value and maintaining the yields of native forages (Halls, 1957;Lewis & Hart, 1972). Low-intensity ground fires may also benefit southern pines by reducing disease problems and slowing the establishment of unwanted shrubs and hardwood trees (Wright & Bailey, 1982). Frequent burning, however, can deplete site productivity because much of the N in vegetation and litter is lost during combustion (Sharrow & Wright, 1977). ...
... Mesquite density in pristine times was probably held in check to some degree by the action of fire (7,25). Fire is known to have occurred periodically on rangelands prior to settlement although the frequency is not well established (41). Fires are presumed to have been ignited naturally by lightning and, because such storms occur principally during warmer months, fires probably occurred mainly during summer months when grasses were dry and highly combustible. ...
... After this time, mesquite becomes increasingly fire tolerant. Research employing fire as a control method for mesquite has been conducted mainly during the winter months when fire can be more easily controlled and intensities are low enough to minimize damage to forage grasses (41). Fires during winter generally do not achieve intensities sufficient to cause top kill on larger trees, although smaller trees may be suppressed. ...
... In the sagebrush (Artemisia L.) ecosystem of the western United States, wildfires are becoming more frequent, larger, and more severe (Crist et al., 2023). Sagebrush communities evolved with periodic fire that shifted dominance from woody vegetation to perennial herbaceous vegetation and prevented conifer encroachment (Wright and Bailey, 1982;Miller and Rose, 1999). However, highly flammable invasive annual grasses, and, at times, coupled with increased human-caused ignitions have altered the fire regimes in these communities (Balch et al., 2013;Fusco et al., 2022;Crist et al., 2023). ...
... Fire, while historically rare and infrequent across North American deserts (Wright and Bailey, 1982), has become an increasingly significant disturbance on the landscape. An examination of Mojave fires over the last four decades indicates a highly heterogeneous regime with varying frequency, severity, and size (Klinger et al., 2021). ...
Soil seed banks help maintain species diversity through temporal storage effects and function as germination pools that can optimize fitness across varying environmental conditions. These characteristics promote the persistence of native plant communities, yet disturbances such as fire and associated invasions by non-native species can disrupt these reserves, fundamentally altering successional trajectories. This may be particularly true in deserts, where native plant communities are less adapted to fire. While studies of fire effects on desert plant communities are not uncommon, information regarding the short- and long-term effects of fire on seed banks is less available. To better understand the influence of fire and invasive species on desert seed banks, we investigated soil seed bank biodiversity from 30 wildfires that burned between 1972 and 2010 across the Mojave Desert ecoregion of North America. We assessed how characteristics of fire regimes (frequency, time since fire, and burn severity) interacted with climate and invasive plants on measures of α-, β-, and γ-diversities. Because β-diversity is a direct measure of community variability and reveals important information about biodiversity loss, we further examined the nestedness and turnover components of β-diversity. Mean α- and γ-diversities were generally higher for burned locations than in unburned reference sites, however individual fire variables had little influence on patterns of seed bank diversity. Burned area seed banks tended to be dominated by non-native invasive species, primarily two grasses, (Bromus rubens, Bromus tectorum), as well as an invasive forb (Erodium cicutarium). The most striking pattern we observed was a collective sharp decline in α-, β-, and γ-diversities with increased invasive species dominance, indicating the homogenization of seed bank communities with the colonization of invasive species after fire. Evidence of homogenization was further supported by reduced turnover and increased nestedness in burn areas compared to reference areas indicating potential biodiversity loss. Our findings highlight how biological processes such as plant invasions can combine with disturbance from fire to alter patterns of seed bank composition and diversity in desert ecosystems.
... There is also a relationship between the areas susceptible to fire and their ecological importance, which must be taken into account for greater care (Rodrigues et al., 2023). However, low severity, recurrent forest low-intensity forest fires in certain ecosystems can have many benefits (Pausas and Keeley, 2019;Wright and Bailey, 1982). Therefore, more research on fire as a management tool and its effects is needed. ...
... The effects of fire, regardless of ignition source, on vegetation and ground cover is an indicator of environmental impact and is visually apparent to the public. However, fire is both a natural and anthropogenic disturbance, and has been suggested as one of the predominant agents of natural disturbance processes structuring the patterns of North American ecosystems (Rowe and Scotter 1973;Wright and Bailey 1982), including the montane cordillera ecozone of Canada which includes critical conservation resource values (Ireland and Petropoulos 2015;Wang et al. 2022). Consequently, differential intensity and spatiotemporal occurrence of wildfires are the cause of landscape and successional heterogeneity (Johnson et al. 1998) which is critical to maintaining mosaics of habitat types for a diverse suite of dependent wildlife species and ecological functions (Agee and Huff 1987;Burton et al. 2009;Leverkus et al. 2017). ...
Pipelines are critical for energy distribution, but incidents causing rupture fires are hazardous. While wildland fires are a natural disturbance, rupture fires are a potential risk and novel disturbance given the greater heat yield constants for fossil fuels, fuel volume, and flaming concentration and duration. We quantified vegetation response to a 2018 rupture fire case study in the montane cordillera of Canada. Plant species, functional groups, ground cover, and live vegetation height were sampled in 2018, 2019, 2020, and 2021 [0, 1, 2, and 3 years since fire (YSF)] in permanent plots stratified by burn severity and compared to the unburned reference plots sampled in 2019. Woody plant species and forb cover in burned plots recovered to levels similar to unburned plots. Litter and bare soil changes relative to YSF suggest trajectories to return to levels similar to unburned plots within 3 to 5 years post-rupture. Plant species richness, evenness, and diversity had also recovered to levels statistically similar to unburned comparisons by the final year of sampling in this study. Plots closest to the rupture epicenter that experienced ‘extreme’ burn had greater botanical dissimilarity from other burn severities or unburned comparisons. Vegetation structure showed significant ( p < 0.0001) recovery with additional growth expected as the overstory re-establishes. The multiple metrics of ecological recovery on 3–5 year trajectories are comparable to published responses to wildland fire in the literature for this ecosystem’s response to fire. The recovery of conifers and soil microbiota should be assessed in the next decade.
... Slopes range from 0 to 15 å nd aspects from north to south at study sites. Soils are Aridisols and Andisols with shallow to moderately deep soil profiles before reaching a restrictive layer ( Lentz & Simonson 1986 ). Historic fire return intervals are estimated to be 50-100 + years for these types of sagebrush steppe communities ( Wright & Bailey 1982 ;Mensing et al. 2006 ). ...
... Disturbed areas are particularly important because both the chemical quality of the plants and the overall net primary productivity of early successional areas are likely to be much higher than those of mature forest (in spite of much lower total biomass). The relative uniformity and high biomass of vegetation that results from high productivity and low disturbance frequencies makes these landscapes subject to rare "catastrophic" disturbances (e.g., stand-replacing fires), which may affect large areas when they occur (Wright and Bailey 1982). ...
The general objective of this Symposium was to build on the best science and technology available to assure that the data and information produced in future inventory and monitoring programs are comparable, quality assured, available, and adequate for their intended purposes, thereby providing a reliable framework for characterization, assessment, and management of forest ecosystems in North America. Central to the syntheses delivered in this Symposium was the conclusion that a fundamental improvement in the approaches used for inventorying and monitoring ecosystem resources is required to meet current and future environmental uncertainties. Specific actions were proposed to address these challenges. These strategic actions are described in the last chapter of these proceedings.
... Fire is a keystone ecological process in the woodlands and forests of the Southwest U.S.A. . Prior to twentieth-century fire suppression, these environments experienced characteristic fire regimes -regular patterns of fire frequency, fire size, seasonality, and environmental impacts (Wright and Bailey 1982). The historical ecology of these fire regimes provides the basis for many contemporary forest management decisions, including determining what role fire should play in these forests and woodlands today. ...
... Removal of wetland vegetation by grazing and other herbivory opens the canopy and often results in plant invasions (Galatowitsch et al. 2000). Fire can similarly impact wetland vegetation by reducing height and density of tall emergent vegetation (Kantrud 1986), releasing nutrients, opening the canopy and allowing more light penetration and may enhance biological productivity (Wright and Bailey 1982). ...
... Frequent fire disturbance helped shape grassland systems in the Great Plains and play an important role in lesser prairiechicken ecology (Axelrod, 1985;Fuhlendorf & Engle, 2001;Samson et al., 2004). An estimated fire return interval of 4-10 years in the southern mixed-grass prairie promoted biodiversity, vegetation heterogeneity, and prevented woody species establishment in grasslands (Axelrod, 1985;Brockway et al., 2002;Wright & Bailey, 1982). ...
Recent studies have documented benefits of small, prescribed fire and wildfire for grassland-dependent wildlife, such as lesser prairie-chickens (Tympanuchus pallidicintus), but wildlife demographic response to the scale and intensity of megafire (wildfire >40,000 ha) in modern, fragmented grasslands remains unknown. Limited available grassland habitat makes it imperative to understand if increasing frequency of megafires could further reduce already declining lesser prairie-chicken populations, or if historical evolutionary interactions with fire make lesser prairie-chickens resilient. To evaluate lesser prairie-chicken demographic response to megafires, we compared lek counts, nest density, and survival rates of adults, nests, and chicks before (2014-2016) and after (2018-2020) a 2017 megafire in the mixed-grass prairie of Kansas, USA (Starbuck fire ~254,000 ha). There was a 67% decline in attending males on leks post-fire and a 57% decline in occupied leks post-fire. Despite population declines as indicated by lek counts, adult female breeding season survival ( S ^ ) was similar pre- ( S ^ = 0.65 ± 0.08 [SE]) and post-fire (0.61 ± 0.08), as was chick survival (pre-fire: 0.23 ± 0.07; post-fire: 0.27 ± 0.11). Nest survival appeared lower post-fire (pre-fire: 0.38 ± 0.06; post-fire: 0.20 ± 0.06), but did not differ at the 95% confidence interval. Nest density of marked females declined 73% in areas burned by megafire. Although lesser prairie-chickens persisted in the study area and we documented minimal effects on most demographic rates, reduced lesser prairie-chicken abundance and reproductive output suggests full recovery may take >3 years. Increased propensity for megafire resulting from suppression of smaller fires, compounded by climate change and woody encroachment, may impose a short-term (3-5 year) threat to already declining lesser prairie-chicken populations.
... High severity fires occur in Deciduous Shrubland during dry summer when fuels are dried and ignited from stem to crown (Crawford et al., 2011). Large trees in Interior Ponderosa Pine are resistant to low severity fires, while intense radiant heat produced by high severity fires can kill mature trees (Wright & Bailey, 1982). The denser foliage and thinner bark of young stands in Interior Ponderosa Pine are prone to crown fire (Bradley, 1992). ...
High severity rangeland wildfires have enormous negative impacts on human safety and infrastructure and may have long‐term consequences on ecosystem structure, function, and services, across the vast rangelands in the western United States. We explored prefire vegetation structure of all high severity wildfires, as well as associated areas with low and moderate burn severity, in nonherbaceous‐dominated rangelands in western United States from 1985 to 2018, based on fractional cover of annual forbs and grasses, perennial forbs and grasses, shrubs and trees from the Rangeland Analysis Platform. These wildfires were grouped into nine clusters using Expectation Maximization algorithms and patterns of prefire vegetation structure and the major vegetation types were assessed. High woody cover is a common characteristic of the prefire vegetation structure. Four of the clusters, which accounted for more than 70% of the areas of high severity wildfires, were characterized by high (∼50%) woody cover in prefire vegetation structure. The areas with high severity burns also had significantly higher woody cover than the areas with low or moderate severity burns in eight of the nine clusters. Some of these ecosystems can have abundant fine fuel, structural connectivity such as fuel laddering, and/or highly flammable materials, which can facilitate the ignition of the woody crowns, leading to high severity wildfires. Management strategies (such as prescribed burning) that can decrease woody cover and reduce standing dead vegetation and fuel laddering could be effective in reducing the risk and extent of high severity wildfires on rangelands in the western United States.
... Pyrogenic material (i.e., plant and topsoil ash) produced from the burning of organic matter constitutes a sizable pool of highly reactive materials which can profoundly affect soil physical and chemical properties. The magnitude of these impacts depends on temperature and duration of combustion, soil moisture content at time of burning and identity and chemical composition of the burning vegetation (Wright and Bailey, 1982;Grey and Dighton, 2006;White-Monsant et al., 2015). Tundra fires are known to strongly impact the carbon and element cycling in high latitudes (de Groot et al., 2013;Hanes et al., 2019;Chen et al., 2021). ...
Extensive studies have been performed on wildfire impact on terrestrial and aquatic ecosystems in the taiga biome, however consequences of wildfires in the tundra biome remain poorly understood. In such a biome, permafrost peatlands occupy a sizable territory in the Northern Hemisphere and present an extensive and highly vulnerable storage of organic carbon. Here we used an experimental approach to model the impact of ash produced from burning of main tundra organic constituents (i.e., moss, lichen and peat) on surrounding aquatic ecosystems. We studied the chemical composition of aqueous leachates produced during short-term (1 week) interaction of ash with distilled water and organic-rich lake water at 5 gsolid L⁻¹ and 20 °C. The addition of ash enriched the fluid phase in major cations (i.e., Na, Ca, Mg), macro- (i.e., P, K, Si) and micronutrients (i.e., Mn, Fe, Co, Ni, Zn, Mo). This enrichment occurred over <2 days of experiment. Among 3 studied substrates, moss ash released the largest amount of macro- and micro-components into the aqueous solution. To place the obtained results in the environmental context of a peatbog watershed, we assume a fire return interval of 56 years and that the entire 0–10 cm of upper peat is subjected to fire impact. These mass balance calculations demonstrated that maximal possible delivery of elements from ash after soil burning to the hydrological network is negligibly small (<1–2 %) compared to the annual riverine export flux and element storage in thermokarst lakes. As such, even a 5–10 fold increase in tundra wildfire frequency may not sizably modify nutrient and metal fluxes and pools in the surrounding aquatic ecosystems. This result requires revisiting the current paradigm on the importance of wildfire impact on permafrost peatlands and calls a need for experimental work on other ecosystem compartments (litter, shrubs, frozen peat) which are subjected to fire events.
... These rangelands are facing unprecedented threats from mega-fires and more frequent fire, putting rural economies and sagebrush-associated wildlife in jeopardy ( Davies et al. 2011 ;USFWS 2013 ;Bates et al. 2020 ). Fire was historically infrequent in these communities and shifted dominance from sagebrush to perennial bunchgrasses ( Wright and Bailey 1982 ;Mensing et al. 2006 ), but exotic annual grass invasion has supplanted succession of native vegetation post fire. Exotic annual grasses often increase after fire in Wyoming big sagebrush communities at the expense of native perennial vegetation ( Steward and Hull 1949 ;Melgoza et al. 1990 ;Mahood and Balch 2019 ) and increase the probability of more frequent fire because of an increase in flammable fine fuel ( Brooks et al. 2004 ;Balch et al. 2013 ), leading to the development of an annual grass −fire cycle ( D'Antonio and Vitousek 1992 ). This, combined with the widespread loss of sagebrush habitat from multiple factors ( Davies et al. 2011 ), has led to a general management objective of limiting fire in Wyoming big JID: RAMA [mUS5Gb;September 2, 2022;11:29 ] sagebrush steppe ( USFWS 2013 ;Mahood and Balch 2019 ;Davies et al. 2021 ). ...
Limiting fire in Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis [Beetle & A. Young] S.L. Welsh) steppe is often a management priority as fires threatens its ecological integrity and rural economies that depend on it. However, the Wyoming big sagebrush steppe is vast and occurs in different community states from intact (sagebrush-bunchgrass dominated) to exotic annual grass dominated. Grazing has been suggested as the only tool that is likely feasible to apply across such large landscapes to manage fine fuels, but there is concern that over time grazing may induce undesirable shifts in plant community composition (e.g., increases in exotic annuals) that increase fire risk. Therefore, we evaluated the longer-term (+10 yr) effects of contemporary, moderate grazing by cattle compared with grazing exclusion on fuel characteristics in three community states: intact, degraded, and exotic annual grass states. We accomplished this by measuring fuel characteristics in five grazed and ungrazed areas in each community state in 2020 and 2021. Grazing generally decreased fine fuel continuity and biomass and increased the live-to-dead ratio. These fuel alterations are consistent with decreasing the probability of fire ignition and, if ignited, producing a slower spreading fire with shorter flame lengths. The response of several fine fuel characteristics to grazing varied by community state. Fine fuel characteristics also commonly varied among community states and between years. These results suggest that fuel management plans need to recognize that grazing effects will vary by community state and be flexible because fuel characteristics vary spatially and temporally. Overall, our results suggest that contemporary grazing in the Wyoming big sagebrush steppe reduces the probability of wildfire and likely increases the effectiveness and safety of fire suppression. Consequently, grazing exclusion in these communities increases the probability of frequent, large wildfires that are difficult and dangerous to suppress.
... The flame temperatures of fires can have a wide range, between 300 and 1500 °C (David, 1987;Wolf et al., 2013;Wright & Bailey, 1982), and the temperatures reached on a shell surface are not uniform. Unlike the controlled muffle furnace heated samples, the burning with fire method was more actualistic as there was a variation in temperatures even with the same experimental method and duration (three instances of fires were made as all the shells could not fit at once). ...
Thermal influences on marine molluscs are poorly understood across all disciplines, including archaeology. This presents potential issues for further analysis including radiocarbon dating and stable isotope analysis, as well as hindering our understandings of processing and preparation methods for shell in the past. Different methods of burning or heating may not always leave visual signs on a shell; however, a variety of structural and chemical changes may take place. Here, we present an experimental study using modern-day shells of five tropical marine species designed to explore how various thermal interventions modified shells in terms of microstructure (scanning electron microscope) and mineralogy (X-ray diffraction). We found distinct differences between the taxa using varied temperatures and durations, with shell microstructure playing a key role in responses to thermal stresses. This study highlights the importance of acknowledging this variation, both when structuring research as well as seeking to interpret archaeological shell remains.
... Fire as a disturbance exists on earth since the beginning of the times (Komarek, 1962;Wright and Bailey, 1982;Pyne, 2020). Fire has greatly contributed to shape the structure and functioning of most terrestrial ecosystems, helped boosted human evolution and development (Attwell et al., 2015;Defossé, 2021), and provided also many ecosystem services (Pausas and Keeley, 2019). ...
Wildland Urban Interface (WUI) areas are rapidly expanding worldwide. In many regions of the world, this expansion could be explained by the increasing possibilities of telecommuting and developing home-office work, while at the same time living in, or surrounded by wilderness areas of magnificent beauty. However, growth and development of these WUIs are still not well dimensioned and regulated, especially in fire prone ecosystems. Over the last two decades, an increasingly number of megafires occurred in these WUI areas in different regions of the world. Recently, big megafires occurred in WUIs located around towns in the western Andean-Patagonian region of Argentina. In this study, we analyzed the evolution of the WUI and its relationship with wildfires around cities and towns located in the northwestern part of Chubut province of Argentina. The studied region covers 324,823 ha and includes the cities of Esquel and Trevelin, and other small villages. Our objectives were to (i) map the current WUI, (ii) quantify changes occurred in the WUI in the last 40 years around the main cities of the region, and (iii) analyze the relationships among WUIs, vegetation types, and wildfire occurrence. We mapped the distribution of WUI using spatially explicit information on housing density derived from censuses and high-resolution imagery from 1981/1982 and 2021, and land cover data. The current WUI covered 8% of the study area, however it has 97% of the houses. Between 1981 and 2021, the WUI area increased by 80%, especially in the southern part of our study region. Finally, information on wildfires distribution revealed that 65% of the ignition points of the recent fires in the region occurred within the WUI. Most of the vegetation burned were herbs, sub-shrubs and woodlands. WUI expansion in our study area appears to be constrained by terrain features (slopes and accessibility), but not by vegetation characteristics. Our study suggests that continuing, unplanned housing expansion in wilderness areas without appropriate vegetation management will likely increases wildfire risk and human environmental conflicts further. Effective land use planning and wildfire management are crucial for sustainable housing expansion in western Patagonia.
... Forests contribute to significant ecological and economic functions in ecosystems [1]. In addition, forests are important heritage sites for human beings. ...
An effective forest-fire response is critical for minimizing the losses caused by forest fires. The purpose of this study is to construct a model for early fire detection and damage area estimation for response systems based on deep learning. First, we implement neural architecture search-based object detection (DetNAS) for searching optimal backbone. Backbone networks play a crucial role in the application of deep learning-based models, as they have a significant impact on the performance of the model. A large-scale fire dataset with approximately 400,000 images is used to train and test object-detection models. Then, the searched light-weight backbone is compared with well-known backbones, such as ResNet, VoVNet, and FBNetV3. In addition, we propose damage area estimation method using Bayesian neural network (BNN), data pertaining to six years of historical forest fire events are employed to estimate the damaged area. Subsequently, a weather API is used to match the recorded events. A BNN model is used as a regression model to estimate the damaged area. Additionally, the trained model is compared with other widely used regression models, such as decision trees and neural networks. The Faster R-CNN with a searched backbone achieves a mean average precision of 27.9 on 40,000 testing images, outperforming existing backbones. Compared with other regression models, the BNN estimates the damage area with less error and increased generalization. Thus, both proposed models demonstrate their robustness and suitability for implementation in real-world systems.
... Big sagebrush (Artemisia tridentata) is a nonresprouting shrub readily killed by fire and is the dominant species of the Great Basin and sagebrush steppe ecosystems of North America (Shultz, 2006). Fire in the sagebrush steppe was historically infrequent, with estimates ranging from 50 to 240 years (Baker, 2006;Wright & Bailey, 1982). Sagebrush communities provide a habitat for several endemic wildlife species, including several declining sagebrush-obligate and specialized species of conservation concern (Rowland et al., 2006). ...
Fire refugia and patchiness are important to the persistence of fire‐sensitive species and may facilitate biodiversity conservation in fire‐dependent landscapes. Playing the role of ecosystem engineers, large herbivores alter vegetation structure and can reduce wildfire risk. However, herbivore effects on the spatial variability of fire and the persistence of fire‐sensitive species are not clear. To examine the hypothesis that large herbivores support the persistence of fire‐sensitive species through the creation of fire refugia in fire‐prone landscapes, we examined the response of a fire‐sensitive plant, Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis [Beetle & Young]) to fire and grazing in the fire‐dependent mixed‐grass prairie of the northern Great Plains. We carried out a controlled burn in 2010 within pre‐established exclosures that allowed differential access to wild and domestic herbivores and no record of fire in the previous 75 years due to fire suppression efforts. The experiment was set up with a split‐plot design to also examine potential changes in plots that were not burned. Canopy cover of big sagebrush was recorded before the burn in 2010 and again in 2011 with percent area burned recorded within 1‐month post‐fire in the burned plots. Percentage area burned was the greatest in ungulate exclosures (92% ± 2%) and the least in open areas (55% ± 21%), suggesting that large herbivores influenced fire behavior (e.g., reducing fire intensity and rate of spread) and are likely to increase fire patchiness through their alterations to the fuel bed. Regression analysis indicated that the proportion of sagebrush cover lost was significantly correlated with the proportion of area burned (R² = 0.76, p = 0.05). No differences in the non‐burn plots were observed among grazing treatments or among years. Altogether, this illustrates the potential importance of large herbivores in creating biotic‐driven fire refugia for fire‐sensitive species to survive within the flammable fuel matrix of fire‐dependent grassland ecosystems such as the mixed‐grass prairie. Our findings also attest to the resiliency of the northern Great Plains to fire and herbivory and underscore the value of managing grasslands for heterogeneity with spatial and temporal variations in these historic disturbances.
... Soils at the study sites are Aridisols and Andisols with shallow to moderately deep soil profiles before reaching a restrictive layer. Historic fire return intervals are estimated to be 50-100 + years for these sagebrush plant communities (Wright and Bailey 1982;Mensing et al., 2006). There was no record or evidence that these plant communities burned in the last + 80 years. ...
Spatial heterogeneity in plant communities promotes coexistence and diversity by providing a variety of niches for different species. In shrub-steppe communities, shrubs create distinct microsites under their canopies (canopy microsites) compared to areas between their canopies (interspace microsites). This creates spatial heterogeneity in soil nutrient availability and herbaceous vegetation. Grazing can influence spatial heterogeneity, but the effect of grazing on shrub-induced spatial heterogeneity is largely unknown. We investigated the long-term (+80 yrs.) effects of moderate grazing by cattle on sagebrush (Artemisia)-induced spatial heterogeneity in soil nutrients, herbaceous vegetation, and ground cover in sagebrush-bunchgrass steppe communities at eight sites in southeastern Oregon. Each site consisted of a long-term grazing exclosure and an adjacent grazed area. Almost all measured herbaceous vegetation (cover, density, diversity, and evenness) and ground cover variables differed between canopy and interspace microsites. Grazing did not influence the effects of microsites on most measured herbaceous vegetation characteristics and ground cover variables. Available soil nutrients were not influenced by grazing, but the majority differed between microsites. The limited effect of moderate grazing on shrub-induced spatial heterogeneity provides evidence that sagebrush exerts a strong influence on patterns of soil nutrients and herbaceous vegetation in sagebrush-bunchgrass communities. These results also demonstrate that moderate grazing by cattle can be compatible with maintaining spatial heterogeneity within shrub-steppe communities. In these ecosystems, maintaining and restoring shrubs is critical to promoting spatial heterogeneity, thereby encouraging coexistence and diversity.
... Study sites were on Sandy Loam 10-12 PZ (R023XY213OR) and Droughty Loam 11-13 PZ (R023XY316OR) Ecological Sites. Historical fire occurrence for these steppe communities was infrequent with fire return intervals estimated to be 50 −100 + yr ( Wright and Bailey 1982 ;Mensing et al. 2006 ). We could find no evidence or record of recent ( ∼ 50 yr) fire at the study sites. ...
Exotic annual grass invasion and dominance of sagebrush-bunchgrass steppe is a concern because it decreases biodiversity and promotes frequent wildfires. Management is needed to reduce exotic annual grasses to prevent sagebrush-bunchgrass communities from transitioning to annual grasslands. Grazing during the off season (fall-winter) has shown promise at reducing exotic annual grasses, but it has not been evaluated in plant communities dominated by sagebrush and native bunchgrasses. We compared moderate grazing during the off season with not grazing in five Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis [Beetle & A. Young] S.L. Welsh)−bunchgrass communities in the northern Great Basin. Treatments were applied annually for 10 yr (2009−2010 through 2018−2019). Plant community characteristics were measured after treatments had been applied from 6 to 10 yr. Off-season grazing reduced exotic annual grass density and cover. After a decade, annual grass cover was twofold greater in ungrazed areas. Sandberg bluegrass (Poa secunda J. Presl) density increased with off-season grazing, but large bunchgrass density was similar between off-season grazed and ungrazed areas. Perennial and annual forb density and cover were similar between off-season grazed and ungrazed treatments. Biological soil crust cover was also similar between off-season grazed and ungrazed areas. The results of this study provide strong evidence that off-season grazing has application for managing exotic annual grasses in sagebrush-bunchgrass steppe. Considering the vast scope of the exotic annual grass problem, properly applied grazing may be the most cost-efficient tool to mediate the impacts of annual grass invasion.
... Such was not the case, however, as resprouting decreased at higher wind speeds and lower RH levels. This result suggests that high wind and low RH led to higher heat release rates and greater stem heating and is consistent with previously established effects of weather on fire effects (Britton and Wright, 1971;Rothermel, 1972;Wright and Bailey, 1982). ...
Rangelands worldwide have experienced significant shifts from grass-dominated to woody-plant dominated states over the past century. In North America, these shifts are largely driven by overgrazing and landscape-scale fire suppression. Such shifts reduce productivity for livestock, can have broad-scale impacts to biodiversity, and are often difficult to reverse. Restoring grass dominance often involves restoring fire as an ecological process. However, many resprouting woody plants persist following disturbance, including fire, by resprouting from protected buds, rendering fire ineffective for reducing resprouting woody plant density. Recent research has shown that extreme fire (high-energy fires during periods of water stress) may reduce resprouting capacity. This previous research did not examine whether high-energy fires alone would be sufficient to cause mortality. We created an experimental framework for assessing the “buds-protection-resources” hypothesis of resprouting persistence under different fire energies. In July–August 2018 we exposed 48 individuals of a dominant resprouting woody plant in the region, honey mesquite (Prosopis glandulosa), to two levels of fire energy (high and low) and root crown exposure (exposed vs unexposed) and evaluated resprouting capacity. We censused basal and epicormic resprouts for two years following treatment. Water stress was moderate for several months leading up to fires but low in subsequent years. Epicormic and basal buds were somewhat protected from low- and high-energy fire. However, epicormic buds were protected in very few mesquites subjected to high-energy fires. High-energy fires decreased survival, caused loss of apical dominance, and left residual dead stems, which may increase chances of mortality from future fires. Basal resprout numbers were reduced by high-energy fires, which may have additional implications for long-term mesquite survival. While the buds, protection, and resources components of resprouter persistence all played a role in resprouting, high-energy fire decreased mesquite survival and reduced resprouting. This suggests that high-energy fires affect persistence mechanisms to different extents than low-energy fires. In addition, high-energy fires during normal rainfall can have negative impacts on resprouting capacity; water stress is not a necessary precursor to honey mesquite mortality from high-energy fire.
... Winter burning combined with favorable spring growing conditions promotes plant recruitment and growth, thereby enhancing fine-fuels, especially with the presence of invasive grasses. The relatively short recovery period of fine-fuels found in our study supports previous findings of semi-arid grassland fires [16,66,67]. Although we expected higher interannual variability of finefuels associated with climatic fluctuations, the variability was relatively low and might be explained by the high resilience of grasses to fire, the dominance of perennial grasses in our study area that have lower interannual changes than annual grasses, and the maintenance of fuel through time by the highly productive invasive Lehmann lovegrass. ...
The spread of flammable invasive grasses, woody plant encroachment, and enhanced aridity have interacted in many grasslands globally to increase wildfire activity and risk to valued assets. Annual variation in the abundance and distribution of fine-fuel present challenges to land managers implementing prescribed burns and mitigating wildfire, although methods to produce high-resolution fuel estimates are still under development. To further understand how prescribed fire and wildfire influence fine-fuels in a semi-arid grassland invaded by non-native perennial grasses, we combined high-resolution Sentinel-2A imagery with in situ vegetation data and machine learning to estimate yearly fine-fuel loads from 2015 to 2020. The resulting model of fine-fuel corresponded to field-based validation measurements taken in the first (R2 = 0.52, RMSE = 218 kg/ha) and last year (R2 = 0.63, RMSE = 196 kg/ha) of this 6-year study. Serial prediction of the fine-fuel model allowed for an assessment of the effect of prescribed fire (average reduction of −80 kg/ha 1-year post fire) and wildfire (−260 kg/ha 1-year post fire) on fuel conditions. Post-fire fine-fuel loads were significantly lower than in unburned control areas sampled just outside fire perimeters from 2015 to 2020 across all fires (t = 1.67, p < 0.0001); however, fine-fuel recovery occurred within 3–5 years, depending upon burn and climate conditions. When coupled with detailed fuels data from field measurements, Sentinel-2A imagery provided a means for evaluating grassland fine-fuels at yearly time steps and shows high potential for extended monitoring of dryland fuels. Our approach provides land managers with a systematic analysis of the effects of fire management treatments on fine-fuel conditions and provides an accurate, updateable, and expandable solution for mapping fine-fuels over yearly time steps across drylands throughout the world.
... palustris)) and can also remove nutrients via high intensity burns and sediment loss through increased erosion exposure to rainfall [3,4]. Research involving "burn vs. non-burn" treatments demonstrated an increase in diversity over time of both plants and animals [5,6]. While prescribed fires may be overall beneficial for the plant and animal community, they may induce energetically costly behaviors from wildlife to avoid an active fire, or death. ...
Prescribed fires are a forest management tool used to improve natural areas for a variety of benefits including increased plant diversity, reduced competition for desired species, decreased fuel loads, and improved wildlife habitat. The post-fire results in landscapes have shown positive benefits for bat populations. However, prescribed fires set in the winter may cause direct mortality of eastern red bat (Lasiurus borealis) populations that use leaf litter for roosting during periods of colder (<10 °C) temperatures. Therefore, we used controlled laboratory techniques to explore if eastern red bats arouse from torpor when exposed to cues associated with fire (i.e., smoke and the sound of fire). Through subsequent field trials, we confirmed latencies of first response (i.e., movement or increased respiration), arousal, and flight behaviors to the stimuli of fire. We provide evidence of smoke influencing eastern red bat first response and arousal through laboratory and field trial results. Latencies of all behaviors were negatively correlated with temperatures and wind speeds prior to and during field trials. We recommend prescribing winter fires on days when temperatures are >10 °C to provide eastern red bats with a better chance to passively rewarm and react to an approaching fire.
... Prescribed burns encourage the growth of native perennial grasses that are tolerant of fire or have adopted reproductive strategies that allow them to increase in abundance following fire. Grasses generally recover to preburn levels within three years (McClaran and Van Devender 1995, Cable 1967, Wright and Bailey 1982. However, annual dicots are also adapted to fire and may dominate for the first few years after a burn while perennial grasses recover (Gonzales 2006, McClaran and Van Devender 1995, Bock and Bock 1990, Bock et al. 1976). ...
The Muleshoe Ranch is a cooperatively managed Nature Conservancy Preserve located in the desert grassland of southeastern Arizona. The desert grassland ecosystem is sensitive to change, as the species composition is dependent on the set of conditions particular to this region (McClaran and Van Devender 1995, Gonzales 2006). There was a prescribed burn several years ago at the Muleshoe Ranch, after which annual dicots began to grow in some habitats. It is natural for annual plants to dominate at first, while the perennials recover after a fire (McClaran and Van Devender 1995); in this case however, some patches remain dominated by annuals. The species of perennial grasses used in this study include; Bouteloua curtipendula (sideoats grama), Muhlenbergia porteri (bush muhly), Bouteloua eriopoda (black grama), Bouteloua chondrosoides (spruce-top grama) and Aristida ternipes (spider-grass). Differences between soils from habitats dominated by perennial grasses and annuals were examined. Germination experiments were performed in the laboratory and in the field to compare the growth of perennial grass species in soil from the different habitat types. Paired annual and grassy transects in two different locations were used to assess overall abundance of all plant species (June 2008) and biomass (August 2008). Results indicate a difference in soil electrical conductivity between sites. Germination was not significantly affected by habitat type. The frequency of perennial grasses was greater in transects in grassy habitats versus annual habitats. Biomass from the transects showed no significant patterns. It is important to understand what is happening to the plant community so that the Muleshoe Ranch can continue to be restoratively managed, and the natural desert grassland community can persist (Suding et al. 2004).
... Although the impacts of fire are many and include responses to smoke and other factors, here we focus specifically on fire-induced soil heating. Heat has major impacts on biological organisms, as well as biogeochemical cycles (Wright and Bailey, 1982), and focusing on the legacy of heating and how this relates to plant growth allowed us to attribute our findings more directly to our treatments. ...
Biological soil crusts (biocrusts) are communities predominately comprised of lichens, bryophytes, fungi, algae, and cyanobacteria that form at the soil surface in dryland ecosystems worldwide. Biocrusts can influence the vascular plant community by altering surface hydrology, nutrient cycling, and the availability of microsites suitable for germination. Fire frequency has increased in many dryland systems, but the potential impacts of fire on biocrust-plant interactions remains unclear. Our study explores how biocrusts and the heating associated with fire affect plant growth across five North American desert sites: the Chihuahuan, Colorado Plateau, Great Basin, Mojave, and Sonoran. Using field-collected biocrusts and mineral soil samples from each of these five deserts, we investigated soil biogeochemical differences and the implications of soil heating and biocrust cover on greenhouse grown Elymus elymoides plants. Results showed plant biomass and leaf production were largely determined by the desert where soils originated, and that the soils collected from the Great Basin site, whether heated or not, were generally higher in nutrients and distinct from the other North American desert sites. In contrast, the Chihuahuan site was lower in nutrients and plant biomass growth compared with the other desert sites. In the short term, biocrusts and heating did not significantly affect the biogeochemical profile of individual desert site soils. However, biocrusts and soil heating positively influenced plant growth, and the combination of these factors influenced plants more strongly than either factor considered separately. These findings highlight the importance of biocrusts in mediating resources and suggest additional mechanisms through which fire may alter or accentuate dynamics between biocrusts and vascular plants.
... 15 In addition, B. procyonis eggs remain within the top 10 cm of the soil surface and can survive for at least 2 years in soils. 37 Also, because soil has insulating properties against extreme high temperatures, 44 pouring boiling water onto contaminated soil can kill most B. procyonis eggs on the surface, but water apparently cools too quickly on dry soil to percolate deeper and be effective in killing eggs at lower depths. In addition, one must be careful to avoid pouring water too quickly onto the soil surface, which can cause splashing and dissipate eggs even further from its origin, thus creating an even greater contamination area. ...
Caregivers of captive wildlife are at risk of zoonotic diseases because they have prolonged contact with and potential exposure to many species of wildlife, their bodily fluids, and feces. One such zoonosis is Baylisascaris procyonis, an intestinal parasite of raccoons (Procyon lotor). Larvae of B. procyonis can cause blindness, paralysis, and death in intermediate hosts, including humans. An infected population of raccoons can contaminate a wildlife facility, and thus expose the animals and their caretakers to a potentially debilitating and fatal parasite. Our objectives were to 1) determine the prevalence of B. procyonis-positive scats and raccoons within a wildlife facility, 2) determine the potential exposure of B. procyonis to captive wildlife and human caregivers, and 3) determine the most effective method to neutralize potential transmission of B. procyonis. During a 12-month period from July 2017 through June 2018, we captured 50 wild raccoons, 23 (46%) of which were infected with a total of 295 B. procyonis roundworms. Eighteen of 120 raccoon scats (15%) collected throughout the facility during the same period were infected with B. procyonis. We estimated about 20% of the total areas that house animals within the facility have B. procyonis-contaminated soil. Therefore, captive animals have the potential of contracting the parasite. A disproportionally greater number of B. procyonis-contaminated scats were found in and around food bins within the facility; thus, wildlife caregivers were exposed to potential B. procyonis infection. Flaming soil with a propane pear burner (i.e., gas-injected flaming torch) followed by discing (i.e., tilling the soil) and re-flaming the contaminated area for at least 1 minute/m2 was successful in rendering the majority of B. procyonis eggs within the top 2.5 cm of the soil column unviable. Soaking the contaminated area with water prior to flaming reduced the time needed to render eggs unviable. Personnel should always wear disposable gloves within a wildlife facility and thoroughly wash their hands upon leaving the facility to reduce their transmission risk to this zoonotic parasite.
Duration of an anthropogenic fire event is one aspect of fire use and maintenance that is linked to combustion feature function but has low archaeological visibility. In this study, we describe the transformations to fresh, modern cortical bone with prolonged exposure to heat in order to evaluate the utility of archaeological bone for the recognition of long duration thermal alteration. Cores of bovid cortical bone were heated exposed to air at 300, 550, and 750 °C in a sequence of experimental trials in a Nabertherm muffle furnace for periods of 10 minutes, 9 hours, and 48 hours, plus an extensive cooling period on heat retaining sediments (gravel or gravel compacted with fine quartz sand) to mirror the smoldering and extinguishing of actualistic fires. After heating, bone cores were analyzed with a color tool, Fourier-transform infrared spectroscopy, and X-ray diffraction to evaluate changes in structure, composition, and crystallinity of bioapatite as a function of different temperature thresholds and time. Results indicate that prolonged heating in air induces specific structural and chemical changes in bone compared to shorter duration burned counterparts. Coloration changes also demonstrate that white coloration, a primary characteristic utilized by zooarchaeologists to record information about burning intensity, is not an exclusive indicator of calcination at moderate to high temperatures but may also result from long duration exposures at low temperatures.
Los respondedores de emergencias son la primera línea de apoyo para la atención
de las complejidades que implica cualquier desastre. Sin embargo, los respondedores se someten a un gran estrés emocional, adversidad y riesgos laborales durante las emergencias con potenciales efectos sobre su salud mental. No solo existe un vacío institucional de la atención de la salud mental de los respondedores, sino que su salud mental debe configurarse como una condición específica de su formación. Se plantea este ejercicio como respuesta al vacío institucional de la atención de la salud mental de los respondedores de emergencias. El objetivo de este capítulo es predecir los factores de resiliencia ante eventos estresantes según los estilos de afrontamiento presentes en un grupo de bomberos voluntarios del departamento del Quindío (Colombia). Se empleó un método cuantitativo, descriptivo-correlacional con alcance predictivo. La población objeto fueron los bomberos voluntarios del departamento del Quindío, la muestra se eligió mediante un muestreo no probabilístico de tipo intencional (n = 35).
Se aplicó una ficha de caracterización, la escala de estrategias Coping modificada
(EEC-M) y la escala de resiliencia (EA). Sentirse bien es predicho por la autonomía
(R² = 0.83, β = 1.030, p = .00), búsqueda de apoyo social (R² = 0.83, β = .979, p = .00) y la reevaluación positiva (R² = 0.83, β = .403, p = .02). Se encontró que la búsqueda de apoyo social es influenciada por la ciudad de residencia (F (3, 168) = 4.098, p = .03), el estado civil (F (2, 242) = 5.878, p = .02), antecedentes médicos (F (1, 376) = 9.135, p = .01). Percepción de apoyo familiar (F (2, 311) = 7.557, p = .01), síntomas de ansiedad (F (1, 378) = 9.178, p = .01) y la ideación suicida (F (1, 251) = 6.117, p = .03). Se concluye que las estrategias de afrontamiento predicen en determinada proporción la resiliencia. La resiliencia es un factor fundamental en la formación integral de los bomberos voluntarios.
Cap 4. Evaluación de la amenaza por avenidas torrenciales en el departamento de
Antioquia a escala de cuenca.
Las avenidas torrenciales son eventos altamente destructivos y frecuentes en
ambientes tropicales y terrenos montañosos como Colombia, donde es común la
presencia de asentamientos humanos ubicados sobre abanicos torrenciales. Esta
combinación de factores crea un escenario crítico, donde las avenidas torrenciales
son amenazas naturales que deben entenderse adecuadamente e incorporarse en
los planes de ordenamiento territorial. El presente estudio propone una metodología
para la priorización de cuencas con susceptibilidad y amenaza ante avenidas
torrenciales, con un enfoque regional que permite comprender y caracterizar dichos
eventos. La susceptibilidad de más de 3,000 cuencas del departamento de Antioquia
es caracterizada a través de factores como morfometría, análisis de estabilidad de
laderas y probabilidades de ocurrencia de la precipitación como factor detonante. Los
resultados muestran que cerca de la mitad de las cuencas son de carácter torrencial, y
que el 11% de ellas se encuentra en la categoría más alta de amenaza. Estas cuencas
críticas deben priorizarse para realizar estudios a mayor detalle, que permitan definir
con precisión las potenciales áreas de afectación y el nivel de riesgo asociado para los
elementos expuestos.
The periodic exploitation of the cork coinciding with the wildfire reinforces the vulnerability of the trees by affecting their vigour and their productive potential. Results showed that trees lightly affected by fire (recoverable) manage to overcome the disturbance without major impact on regeneration and growth variables (IR = 3.80, growth = 2.04mm/year; thickness = 14.81mm; volumetric density = 283,59 kg/m3; IQ = 8,56). Paradoxically, standing dead trees record a very low resilience (IR = 1.23; growth = 0.26mm/year; thickness = 1.99mm; volumetric density = 347.02 kg/m3 and IQ = 1.50).
Background
Application of prescribed fire in natural plant communities is an important wildlife habitat management tool. Prescribed fire managers have suggested anecdotally that changing weather patterns may be influencing the frequency of days that have optimal conditions to conduct coastal marsh burns along the US Gulf of Mexico coast. Our study objectives were to (1) determine whether the frequency of atmospheric circulation patterns associated with prescribed fire prescriptions has changed from 1979 to 2018 for the Gulf Coast and (2) identify circulation patterns preferred by land managers for implementing prescribed fire.
Results
While coastal marsh habitat is threatened by climate change and human-associated degradation, weather type frequency was not identified as an important factor related to the application of prescribed fire, as the frequency of weather circulation types has not changed significantly over time ( p > 0.05). However, some weather circulation patterns seem more advantageous (e.g., offshore winds) or disadvantageous (e.g., wet cold fronts and high winds) for consideration by prescribed fire applicators across the Gulf.
Conclusions
Further insight into the weather conditions preferred and avoided by land managers along the Gulf of Mexico will improve prediction-based methods for identifying burn windows from weather forecasts. Land managers face many challenges in protecting coastal systems, while also reducing management conflicts (i.e., smoke transport) with local communities. Understanding how constraints such as urbanization, climate change, and sea-level rise interact to affect prescribed fire application will be an increasingly important aspect for developing successful adaptive management plans.
Context
Prairies historically covered much of inland North America, and many species have adapted to the unique conditions found in prairie ecosystems. Less than 1% of prairies remain in Arkansas, with much historic prairie having been converted for urban and agricultural development, resulting in steep population declines for many prairie-associated species.
Objectives
Because many reptile and amphibian species are difficult to detect, the current distributions and habitat requirements of prairie-associated herpetofauna in fragmented landscapes are poorly understood. Thus, we assessed the state of prairie-associated herpetofauna communities in intact prairie, as well in degraded and developed historic prairie throughout Western Arkansas.
Methods
Using repeated field surveys, remote sensing data, and hierarchical community occupancy models, we examined the influence of vegetation conditions, land use, and landscape characteristics on an assemblage of nine species of prairie-associated herpetofauna.
Results
Prairie mound density, representing prairie that has not been subject to intense anthropogenic disturbance, was the strongest positive predictor of occupancy by prairie-associated species. Historic prairie area also exhibited a positive relationship with occupancy for several species but not at the assemblage level. Current vegetation conditions did not strongly influence occupancy patterns.
Conclusions
Our results suggest that long-term land use filters, rather than present site-level conditions, are the driving forces dictating current distributions of prairie-associate herpetofauna in Western Arkansas. Our findings provide insight into the present state of understudied populations in an increasingly fragmented region and present accessible tools for directing exploratory conservation and research efforts.
Destructive wildfire outbreaks are a preeminent natural hazard on the grass-dominated landscape of the southern Great Plains. These southern Great Plains wildfire outbreaks (SGPWOs) are characterized by tens of wildfires that evolve on spatial and temporal scales closely tied to the passage of midlatitude cyclones when dormant herbaceous vegetation is particularly dry and abundant. Ten SGPWOs inflicted tragic losses of life and property across eastern New Mexico, west Texas, and Oklahoma between December 2005 and April 2009. This study reviews the conditions that promoted these dangerous phenomena. Texas A&M; Forest Service records reveal that enhanced seasonal wildfire activity and increased potential for SGPWOs typically occurs during El Niño Southern Oscillation cold phases (La Niña), especially when preceded by positive growing-season rainfall anomalies. The antecedent state of predominately fine grassland vegetative fuels associated with SGPWOs is quantified per Energy Release Component (ERC, fuel model G). Average ERC values >50 (>70th percentile) supported the 2005-2009 SGPWOs on the Great Plains of Texas. Meteorological composites that quantify mean synoptic patterns during SGPWOs are generated via Rapid Update Cycle analyses, and averaged vertical temperature, moisture, and wind profiles are presented. Further analyses of subsynoptic low and midlevel tropospheric temperatures and winds illustrate a tendency for wildfires to occur near 2-m and 850-hPa thermal ridges when overspread by 500-hPa wind maxima. The juxtaposition of these atmospheric features appears to be a useful meso-α-scale predictor of heightened wildfire risks. Recognition of the presented seasonal indicators toward a fire-prone regime influenced strategic preparations for the historic 2011 Texas wildfires. Operational use of composite pattern recognition-based forecasts in tactical decision support is demonstrated for the 27 February 2011 “firestorm”, a particularly damaging SGPWO during an unprecedented fire season. Average ERC values >75 (>95th percentile) additionally supported prolonged burn periods with the passage of subsequent fire outbreak-bearing weather systems during the spring of 2011. Lastly, seasonal trends and the chronology of climatic and environmental signals prior to SGPWOs are highlighted, per a summary of conditions that preceded all of the 2005-2011 episodes.
Fire ash contains essential nutrients that play an important role in the forest by changing soil properties. The goal of this study was to investigate the physical and chemical properties of ash from burning litter and branches of Aleppo oak (Quercus infectoria Oliv.). Litter and dried branches with a diameter of less than 2 and 2-5 cm were collected under the canopy of eight oak trees in Dezli, Sarvabad county, Kurdistan province. The results showed that the colors of ashes were dark gray (5Y2.5/1) in the litter and light gray(5Y6/1) in both branch treatments. The amount of K, pH and electrical conductivity increased significantly in the ashes of all three treatments compared to unburned samples, while the amount of Ca, organic carbon and total nitrogen were decreased considerably in all three treatments after burning. The amount of P in the ash of the litter increased significantly compared to the unburned litter; however, its amount decreased in both branch treatments. In general, despite the similarity of the pattern of changes in all three treatments, branch treatments showed more differences during the burning than the control, indicating a higher burning of branches compared to the litter.
Few studies have assessed potential differences in foraging behavior between wild‐strain and commercial‐strain gallinaceous chicks often used to assess habitat quality. We conducted field trials during summer 2013 using wild‐strain (n = 54) and commercial‐strain (n = 64) wild turkey (Meleagris gallapavo) poults to assess foraging efficiency and mobility in burned and unburned grassland sections in southern Illinois. Foraging efficiency of turkey poults did not differ between burned or unburned fields, or between wild and commercial‐strain poults. All poults selected invertebrate orders Coleoptera, Hymenoptera, and Isopoda during all field trials, whereas poults avoided orders Araneae, Diptera, Hemiptera, Lepidoptera, and Orthoptera, and orders Collembola, Diplura, and Protura in class Entognatha. Overall, the lack of differences in behavior between poult strains should allow researchers to confidently use commercially‐raised chicks as an alternative to wild‐captured chicks in studies that assess forage quality and travel efficiency.
On the Ground
•Wildfires and incidents of large fires have increased substantially in the past few decades, in part from increases in fine, dry fuels. Fine fuel management is needed, and grazing is likely the only tool applicable at the scale needed to have meaningful effects.
•Moderate grazing decreases wildfire probability by decreasing fuel amount, continuity, and height and increasing fuel moisture content. Grazing, through its modification of fuels, can improve fire suppression efforts by decreasing flame lengths, rate of fire spread, and fire severity.
•Logistical, social, and administrative challenges exist to using grazing to decrease fire probability. Some of these challenges can be overcome by using off-season (i.e., fall-winter) grazing, but other challenges will require persistent efforts as well as science to support management changes.
Nowadays forest fires are so rare in the Mississippi Alluvial Valley and other floodplains of the southeastern USA that these floodplains appear fireproof. Fire was once much more common across the Southeastern Coastal Plain, including in these forested floodplains. Even so, fire was not the fundamental ecological disturbance in floodplain forests that it was in adjacent uplands; flooding served that role here. Other disturbances, like hurricanes, tornados, and beavers opened floodplain forests and may have been antecedents to fires. Since the arrival of Europeans, the disturbance regime in perhaps no other ecoregion in the continental USA has been so fundamentally altered. Levee- and dam-building have radically changed the hydrology of most of these river floodplains. Logging, agricultural conversion, urbanization, and road-building have further altered ecosystem structure and function. Fire is exceedingly rare in modern, closed-canopy floodplain forests, where fuels remain moist year-round, well-drained sites are converted from canebrakes to crop fields, and fires that once burned across adjacent uplands are either halted by habitat fragmentation or actively suppressed. This chapter will discuss the role of fire in floodplains of the southeastern USA in the context of other ecological and human-caused disturbances historically, presently, and looking to the future.
How do plants survive fires? Fires can affect plant crowns, stems, roots, and seeds. Fire effects depend on fire behavior, plant characteristics, and the environment. Heat effects on meristematic tissue are important, for if meristems are greatly damaged by heat, plants may not survive and thrive post fire. We illustrate key concepts with trees (for they have been most studied), shrubs, grasses, and forbs. We include some of the tools used to assess and predict the effects of fire. We illustrate concepts and their implications, using examples from around the globe. Overall, this chapter in our book, Fire science from chemistry to landscape management, is about the ecological effects of fire and how these are linked to the fire behavior concepts covered in earlier chapters. People can manage fires to accomplish more of the positive benefits and fewer negative impacts; doing so effectively depends on understanding how and why fire effects vary from fire to fire and place to place.
Across portions of the western Great Plains in North America, natural fire has been removed from grassland ecosystems, decreasing vegetation heterogeneity and allowing woody encroachment. The loss of fire has implications for grassland species requiring diverse vegetation patches and structure or patches that have limited occurrence in the absence of fire. The lesser prairie‐chicken (Tympanuchus pallidicinctus) is a declining species of prairie‐grouse that requires heterogeneous grasslands throughout its life history and fire has been removed from much of its occupied range. Patch‐burn grazing is a management strategy that re‐establishes the fire‐grazing interaction to a grassland system, increasing heterogeneity in vegetation structure and composition. We evaluated the effects of patch‐burn grazing on lesser prairie‐chicken space use, habitat features, and vegetation selection during a 4‐year field study from 2014–2017. Female lesser prairie‐chickens selected 1‐ and 2‐year post‐fire patches during the lekking season, ≥4‐year post‐fire patches during the nesting season, and year‐of‐fire and 1‐year post‐fire patches during post‐nesting and nonbreeding seasons. Vegetation selection during the lekking season was not similar to available vegetation in selected patches, suggesting that lesser prairie‐chickens cue in on other factors during the lekking season. During the nesting season, females selected nest sites with greater visual obstruction, which was available in ≥4‐year post‐fire patches; during the post‐nesting season, females selected sites with 15–25% bare ground, which was available in the year‐of‐fire, 1‐year post‐fire, and 2‐year post‐fire patches; and during the nonbreeding season they selected sites with lower visual obstruction, available in the year‐of‐fire and 1‐year post‐fire patches. Because lesser prairie‐chickens selected all available time‐since‐fire patches during their life history, patch‐burn grazing may be a viable management tool to restore and maintain lesser prairie‐chicken habitat on the landscape. © 2021 The Wildlife Society. Lesser prairie‐chickens differentially use patches within a patch‐burn grazing mosaic, indicating the need for multiple time‐since‐fire patches on the landscape to ensure required habitats are available. Patch‐burn grazing may be a useful management tool to maintain lesser prairie‐chicken habitat and generate heterogeneity on the landscape for multiple grassland taxa.
This report contains reviews and syntheses of scientific literature for the purpose of informing the development of policies related to management of riparian areas and watersheds of Washington State.
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