Quantifying the fire regime distributions for severity in Yosemite National Park, California, USA

2011 ◽  
Vol 20 (2) ◽  
pp. 223 ◽  
Author(s):  
Andrea E. Thode ◽  
Jan W. van Wagtendonk ◽  
Jay D. Miller ◽  
James F. Quinn
Keyword(s):  
Sierra Nevada ◽  
National Park ◽  
Fire Regime ◽  
Fire Severity ◽  
Fire Regimes ◽  
Montane Forest ◽  
Subalpine Forest ◽  
Yosemite National Park ◽  
Forest Zone ◽  
Frequency Distributions

This paper quantifies current fire severity distributions for 19 different fire-regime types in Yosemite National Park, California, USA. Landsat Thematic Mapper remote sensing data are used to map burn severity for 99 fires (cumulatively over 97 000 ha) that burned in Yosemite over a 20-year period. These maps are used to quantify the frequency distributions of fire severity by fire-regime type. A classification is created for the resultant distributions and they are discussed within the context of four vegetation zones: the foothill shrub and woodland zone; the lower montane forest zone; the upper montane forest zone and the subalpine forest zone. The severity distributions can form a building block from which to discuss current fire regimes across the Sierra Nevada in California. This work establishes a framework for comparing the effects of current fires on our landscapes with our notions of how fires historically burned, and how current fire severity distributions differ from our desired future conditions. As this process is refined, a new set of information will be available to researchers and land managers to help understand how fire regimes have changed from the past and how we might attempt to manage them in the future.

scholarly journals The distribution of woody species in relation to climate and fire in Yosemite National Park, California, USA

Fire Ecology ◽  
2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Jan W. van Wagtendonk ◽  
Peggy E. Moore ◽  
Julie L. Yee ◽  
James A. Lutz
Keyword(s):  
Plant Species ◽  
Sierra Nevada ◽  
Species Distribution ◽  
National Park ◽  
Woody Plant ◽  
Fire Regime ◽  
Yosemite National Park ◽  
Distribution Models ◽  
Ecological Zones ◽  
Woody Plant Species

Abstract Background The effects of climate on plant species ranges are well appreciated, but the effects of other processes, such as fire, on plant species distribution are less well understood. We used a dataset of 561 plots 0.1 ha in size located throughout Yosemite National Park, in the Sierra Nevada of California, USA, to determine the joint effects of fire and climate on woody plant species. We analyzed the effect of climate (annual actual evapotranspiration [AET], climatic water deficit [Deficit]) and fire characteristics (occurrence [BURN] for all plots, fire return interval departure [FRID] for unburned plots, and severity of the most severe fire [dNBR]) on the distribution of woody plant species. Results Of 43 species that were present on at least two plots, 38 species occurred on five or more plots. Of those 38 species, models for the distribution of 13 species (34%) were significantly improved by including the variable for fire occurrence (BURN). Models for the distribution of 10 species (26%) were significantly improved by including FRID, and two species (5%) were improved by including dNBR. Species for which distribution models were improved by inclusion of fire variables included some of the most areally extensive woody plants. Species and ecological zones were aligned along an AET-Deficit gradient from cool and moist to hot and dry conditions. Conclusions In fire-frequent ecosystems, such as those in most of western North America, species distribution models were improved by including variables related to fire. Models for changing species distributions would also be improved by considering potential changes to the fire regime.

Short-term resilience of Great Gray Owls to a megafire in California, USA

The Condor ◽  
2019 ◽  
Vol 121 (1) ◽  
Author(s):  
Rodney B Siegel ◽  
Stephanie A Eyes ◽  
Morgan W Tingley ◽  
Joanna X Wu ◽  
Sarah L Stock ◽  
...  
Keyword(s):  
Sierra Nevada ◽  
National Park ◽  
Hierarchical Modeling ◽  
Fire Regimes ◽  
Burned Area ◽  
National Forest ◽  
Yosemite National Park ◽  
Bayesian Hierarchical ◽  
Rim Fire ◽  
Great Gray Owl

ABSTRACT Throughout western North America, longer, hotter fire seasons and dense fuels are yielding more frequent, larger, and higher-severity wildfires, including uncharacteristically large “megafires.” Wildlife species associated with late-seral forest characteristics may be particularly vulnerable to habitat loss stemming from changing fire regimes. The Great Gray Owl (Strix nebulosa) is a state-listed endangered species in California that typically nests in large snags in well-shaded forests adjacent to montane meadows. The 2013 Rim Fire burned 104,000 ha in Yosemite National Park and Stanislaus National Forest, making it the largest recorded fire in California’s Sierra Nevada. The fire perimeter contained 23 meadows known to be occupied by Great Gray Owls during the decade prior to the fire, representing nearly a quarter of all known or suspected territories in California at the time. We analyzed 13 yr (2004–2016) of Great Gray Owl detection/non-detection data from 144 meadows in the central Sierra Nevada, including meadows inside and outside the Rim Fire perimeter in Yosemite National Park and on Stanislaus National Forest. During 3 yr of surveys after the fire, Great Gray Owls were detected at 21 of 22 meadows surveyed within the fire perimeter that were occupied during the decade prior to the fire. Bayesian hierarchical modeling revealed that, rather than decreasing after the fire, persistence of owls at meadows actually increased on both National Park Service (NPS) and non-NPS lands, while colonization rates exhibited no significant change. Within the burned area, these dynamics were unrelated to forest structure variables describing post-fire stands around individual meadows. Notably, post-fire increases in owl persistence occurred both inside and outside the fire perimeter, suggesting factors other than the fire were likely favorable to Great Gray Owls during the post-fire years. Great Gray Owls appear to have been largely resilient to effects of the Rim Fire during the 3 yr after it burned.

Fire regime impacts on post-fire diurnal land surface temperature change over North American boreal forest

2021 ◽  
Author(s):  
Jie Zhao ◽  
Chao Yue ◽  
Philippe Ciais ◽  
Xin Hou ◽  
Qi Tian
Keyword(s):  
Climate Change ◽  
Regression Analysis ◽  
Land Surface ◽  
Fire Regime ◽  
Fire Severity ◽  
Linear Regression Analysis ◽  
Fire Regimes ◽  
Fire Intensity ◽  
Surface Temperature Change ◽  
One Year

<p>Wildfire is the most prevalent natural disturbance in the North American boreal (BNA) forest and can cause post-fire land surface temperature change (ΔLST<sub>fire</sub>) through biophysical processes. Fire regimes, such as fire severity, fire intensity and percentage of burned area (PBA), might affect ΔLST<sub>fire</sub> through their impacts on post-fire vegetation damage. However, the difference of the influence of different fire regimes on the ΔLST<sub>fire</sub> has not been quantified in previous studies, despite ongoing and projected changes in fire regimes in BNA in association with climate change. Here we employed satellite observations and a space-and-time approach to investigate diurnal ΔLST<sub>fire</sub> one year after fire across BNA. We further examined potential impacts of three fire regimes (i.e., fire intensity, fire severity and PBA) and latitude on ΔLST<sub>fire</sub> by simple linear regression analysis and multiple linear regression analysis in a stepwise manner. Our results demonstrated pronounced asymmetry in diurnal ΔLST<sub>fire</sub>, characterized by daytime warming in contrast to nighttime cooling over most BNA. Such diurnal ΔLST<sub>fire</sub> also exhibits a clear latitudinal pattern, with stronger daytime warming and nighttime cooling one year after fire in lower latitudes, whereas in high latitudes fire effects are almost neutral. Among the fire regimes, fire severity accounted for the most (43.65%) of the variation of daytime ΔLST<sub>fire</sub>, followed by PBA (11.6%) and fire intensity (8.5%). The latitude is an important factor affecting the influence of fire regimes on daytime ΔLST<sub>fire</sub>. The sensitivity of fire intensity and PBA impact on daytime ΔLST<sub>fire</sub> decreases with latitude. But only fire severity had a significant effect on nighttime ΔLST<sub>fire</sub> among three fire regimes. Our results highlight important fire regime impacts on daytime ΔLST<sub>fire</sub>, which might play a critical role in catalyzing future boreal climate change through positive feedbacks between fire regime and post-fire surface warming.</p>

Landscape-scale effects of fire severity on mixed-conifer and red fir forest structure in Yosemite National Park

2013 ◽  
Vol 287 ◽  
pp. 17-31 ◽  
Author(s):  
Van R. Kane ◽  
James A. Lutz ◽  
Susan L. Roberts ◽  
Douglas F. Smith ◽  
Robert J. McGaughey ◽  
...  
Keyword(s):  
Forest Structure ◽  
National Park ◽  
Scale Effects ◽  
Fire Severity ◽  
Landscape Scale ◽  
Yosemite National Park ◽  
Mixed Conifer

Fire regimes and interval-sensitive vegetation in semiarid Gregory National Park, northern Australia

2010 ◽  
Vol 58 (4) ◽  
pp. 300 ◽  
Author(s):  
Jeremy Russell-Smith ◽  
Cameron P. Yates ◽  
Chris Brock ◽  
Vanessa C. Westcott
Keyword(s):  
National Park ◽  
Fire Regime ◽  
Woody Species ◽  
Fire Regimes ◽  
Stem Density ◽  
Northern Australia ◽  
Juvenile Period ◽  
Climate Conditions ◽  
Fine Fuels ◽  
Ecologically Sustainable

Few data are available concerning contemporary fire regimes and the responses of fire interval-sensitive vegetation types in semiarid woodland savanna landscapes of northern Australia. For a 10 300 km2 semiarid portion of Gregory National Park, in the present paper we describe (1) components of the contemporary fire regime for 1998–2008, on the basis of assessments derived from Landsat and MODIS imagery, (2) for the same period, the population dynamics, and characteristic fine-fuel loads associated with Acacia shirleyi Maiden (lancewood), an obligate seeder tree species occurring in dense monodominant stands, and (3) the fire responses of woody species, and fine-fuel dynamics, sampled in 41 plots comprising shrubby open-woodland over spinifex hummock grassland. While rain-year (July–June) rainfall was consistently reliable over the study period, annual fire extent fluctuated markedly, with an average of 29% being fire affected, mostly in the latter part of the year under relatively harsh fire-climate conditions. Collectively, such conditions facilitated short fire-return intervals, with 30% of the study area experiencing a repeat fire within 1 year, and 80% experiencing a repeat fire within 3 years. Fine fuels associated with the interior of lancewood thickets were characteristically small (<1 t ha–1). Fine fuels dominated by spinifex (Triodia spp.) were found to accumulate at rates equivalent to those observed under higher-rainfall conditions. Stand boundaries of A. shirleyi faired poorly under prevailing fire regimes over the study period; in 16 plots, juvenile density declined 62%, and adult stem density and basal area declined by 53% and 40%, respectively. Although the maturation (primary juvenile) period of A. shirleyi is incompletely known, assembled growth rate and phenology data indicated that it is typically >10 years. Of 133 woody species sampled, all trees (n = 26), with the exception of A. shirleyi, were resprouters, and 58% of all shrub species (n = 105) were obligate seeders, with observed primary juvenile periods <5 years. Assembled data generally supported observations made from other northern Australian studies concerning the responses of fire-sensitive woody taxa in rugged, sandstone-derived landscapes, and illustrated the enormous challenges facing ecologically sustainable fire management in such settings. Contemporary fire regimes of Gregory National Park are not ecologically sustainable.

scholarly journals A Comparison of Fire Regimes and Stand Dynamics in Whitebark Pine (Pinus albicaulis) Communities in the Greater Yellowstone Ecosystem

2003 ◽  
Vol 27 ◽  
pp. 123-128
Author(s):  
William Romme ◽  
James Walsh
Keyword(s):  
Yellowstone National Park ◽  
National Park ◽  
Fire Regime ◽  
Fire Regimes ◽  
Greater Yellowstone Ecosystem ◽  
Past Century ◽  
Grizzly Bear ◽  
Pinus Albicaulis ◽  
Whitebark Pine ◽  
Greater Yellowstone

Whitebark pine (Pinus albicaulis) is a keystone species of upper subalpine ecosystems (Tomback et al. 2001), and is especially important in the high-elevation ecosystems of the northern Rocky Mountains (Arno and Hoff 1989). Its seeds are an essential food source for the endangered grizzly bear (Ursus arctos horribilis), particularly in the autumn, prior to winter denning (Mattson and Jonkel 1990, Mattson and Reinhart 1990, Mattson et al. 1992). In the Greater Yellowstone Ecosystem (GYE), biologists have concluded that the fate of grizzlies is intrinsically linked to the health of the whitebark pine communities found in and around Yellowstone National Park (YNP) (Mattson and Merrill 2002). Over the past century, however, whitebark pine has severely declined throughout much of its range as a result of an introduced fungus, white pine blister rust (Cronartium ribicola) (Hoff and Hagle 1990, Smith and Hoffman 2000, McDonald and Hoff 2001), native pine beetle (Dendroctonus ponderosae) infestations (Bartos and Gibson 1990, Kendall and Keane 2001), and, perhaps in some locations, successional replacement related to fire exclusion and fire suppression (Amo 2001). The most common historical whitebark pine ftre regimes are "stand-replacement", and "mixed­ severity" regimes (Morgan et al. 1994, Arno 2000, Arno and Allison-Bunnell2002). In the GYE, mixed-severity ftre regimes have been documented in whitebark pine forests in the Shoshone National forest NW of Cody, WY (Morgan and Bunting 1990), and in NE Yellowstone National Park (Barrett 1994). In Western Montana and Idaho, mixed fire regimes have been documented in whitebark pine communities in the Bob Marshall Wilderness (Keane et al. 1994), Selway-Bitterroot Wilderness (Brown et al. 1994), and the West Bighole Range (Murray et al.1998). Mattson and Reinhart (1990) found a stand­replacing fire regime on the Mount Washburn Massif, within Yellowstone National Park.

Older forests used by northern spotted owls functioned as fire refugia during large wildfires, 1987–2017

2021 ◽  
Author(s):  
Damon B Lesmeister ◽  
Raymond J. Davis ◽  
Stan G. Sovern ◽  
Zhiqiang Yang
Keyword(s):  
Fire Regime ◽  
Fire Severity ◽  
Weather Conditions ◽  
Fire Regimes ◽  
Bimodal Distribution ◽  
Relative Difference ◽  
Positive Trend ◽  
Forest Types ◽  
Spotted Owl ◽  
High Severity

Abstract Background The northern spotted owl (Strix occidentalis caurina) is an Endangered Species Act-listed subspecies that requires forests with old-growth characteristics for nesting. With climate change, large, severe wildfires are expected to be more common and an increasing threat to spotted owl persistence. Understanding fire severity patterns related to nesting forest can be valuable for forest management that supports conservation and recovery, especially if nesting forest functions as fire refugia (i.e., lower fire severity than surrounding landscape). We examined the relationship between fire severity and nesting forests in 472 large wildfires (> 200 ha) that occurred rangewide during 1987–2017. We mapped fire severities (unburned-low, moderate, high) within each fire using relative difference normalized burn ratios and quantified differences in severity between pre-fire nesting forest (edge and interior) and non-nesting forest. We also quantified these relationships within areas of three fire regimes (low severity, very frequent; mixed severity, frequent; high severity, infrequent). Results Averaged over all fires, the interior nesting forest burned at lower severity than edge or non-nesting forest. These relationships were consistent within the low severity, very frequent and mixed severity, frequent fire regime areas. All forest types burned at similar severity within the high severity, infrequent fire regime. During two of the most active wildfire years that also had the largest wildfires occurring in rare and extreme weather conditions, we found a bimodal distribution of fire severity in all forest types. In those years, a higher amount—and proportion—of all forest types burned at high severity. Over the duration of the study, we found a strong positive trend in the proportion of wildfires that burned at high severity in the non-nesting forests, but not in the two nesting forest types. Conclusions Under most wildfire conditions, the microclimate of interior patches of nesting forests likely mitigated fire severity and thus functioned as fire refugia. With changing climates, the future of interior forest as fire refugia is unknown, but trends suggest these older forests can dampen the effect of increased wildfire activity and thus an important component of landscape plans focused on fire resiliency.

scholarly journals Visualizing When, Where, and How Fires Happen in U.S. Parks and Protected Areas

2020 ◽  
Vol 9 (5) ◽  
pp. 333
Author(s):  
Nicole C. Inglis ◽  
Jelena Vukomanovic
Keyword(s):  
Decision Making ◽  
Protected Areas ◽  
National Park ◽  
Fire History ◽  
National Park Service ◽  
Fire Management ◽  
Fire Regime ◽  
Fire Regimes ◽  
The United States ◽  
Park Service

Fire management in protected areas faces mounting obstacles as climate change alters disturbance regimes, resources are diverted to fighting wildfires, and more people live along the boundaries of parks. Evidence-based prescribed fire management and improved communication with stakeholders is vital to reducing fire risk while maintaining public trust. Numerous national fire databases document when and where natural, prescribed, and human-caused fires have occurred on public lands in the United States. However, these databases are incongruous and non-standardized, making it difficult to visualize spatiotemporal patterns of fire and engage stakeholders in decision-making. We created interactive decision analytics (“VISTAFiRe”) that transform fire history data into clear visualizations of the spatial and temporal dimensions of fire and its management. We demonstrate the utility of our approach using Big Cypress National Preserve and Everglades National Park as examples of protected areas experiencing fire regime change between 1980 and 2017. Our open source visualizations may be applied to any data from the National Park Service Wildland Fire Events Geodatabase, with flexibility to communicate shifts in fire regimes over time, such as the type of ignition, duration and magnitude, and changes in seasonal occurrence. Application of the tool to Everglades and Big Cypress revealed that natural wildfires are occurring earlier in the wildfire season, while human-caused and prescribed wildfires are becoming less and more common, respectively. These new avenues of stakeholder communication are allowing the National Park Service to devise research plans to prepare for environmental change, guide resource allocation, and support decision-making in a clear and timely manner.

scholarly journals Modeling the Effects of Fire Severity and Spatial Complexity on Small Mammals in Yosemite National Park, California

Fire Ecology ◽  
2008 ◽  
Vol 4 (2) ◽  
pp. 83-104 ◽  
Author(s):  
Susan L. Roberts ◽  
Jan W. van Wagtendonk ◽  
A. Keith Miles ◽  
Douglas A. Kelt ◽  
James A. Lutz
Keyword(s):  
Small Mammals ◽  
National Park ◽  
Fire Severity ◽  
Yosemite National Park ◽  
Spatial Complexity
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