High-severity fire reduces early successional boreal larch forest aboveground productivity by shifting stand density in north-eastern China

2016 ◽  
Vol 25 (8) ◽  
pp. 861 ◽  
Author(s):  
Wen H. Cai ◽  
Jian Yang
Keyword(s):  
Carbon Storage ◽  
Forest Structure ◽  
Forest Regeneration ◽  
Fire Severity ◽  
Eastern China ◽  
Larch Forest ◽  
Understorey Vegetation ◽  
High Severity ◽  
Sapling Density ◽  
Tree Sapling

Climate warming is predicted to increase fire activity across the Eurasian boreal larch forest in the 21st century, which could have serious consequences on carbon storage. Quantifying the effects of fire disturbance on forest structure and aboveground net primary productivity (ANPP) could aid in our ability to predict future carbon storage on a regional and biome level. In this study, we examined the spatial heterogeneity of forest structure and ANPP on sites of varying fire severity and topographic position in a recently burned landscape in the Great Xing’an Mountains, China. Results indicated that after 11 years of vegetation regrowth, fire severity significantly affected forest regeneration ANPP. Spatial heterogeneities in forest regeneration ANPP were explained by both tree sapling density and understorey vegetation abundance. Although understorey vegetation productivity on average contributed 50% of total ANPP after fire, the increase in understorey productivity with fire severity could not offset the decrease in tree productivity in severely burned stands where tree sapling density was limited. Our results suggest that high-severity fire can decrease forest regeneration ANPP by altering forest structure in the early post-fire successional stage and that this shift in forest structure may influence future forest productivity trajectories over an extended period.

Fuel treatments change forest structure and spatial patterns of fire severity, Arizona, U.S.A.

2019 ◽  
Vol 49 (11) ◽  
pp. 1357-1370
Author(s):  
Morris C. Johnson ◽  
Maureen C. Kennedy ◽  
Sarah Harrison
Keyword(s):  
Forest Structure ◽  
Fire Severity ◽  
Fire Effects ◽  
Wildlife Habitat ◽  
Fuel Treatments ◽  
Treatment Unit ◽  
Fuel Treatment ◽  
Treated Area ◽  
High Severity ◽  
Management Objectives

Fuel reduction treatments are often designed to achieve multiple resource management objectives in addition to reducing potential fire hazard. In the White Mountains of Arizona State (U.S.A.), the 2014 San Juan Fire burned through several thinning prescriptions designed to achieve wildlife habitat objectives. Many studies have documented reduced fire severity for a standard set of fuel treatments, but the range of variability in fuel treatment effectiveness for alternative treatment designs is poorly understood. We used nonlinear mixed-effects modeling to estimate the distance into the treated area at which fire severity decreases and randomization tests to compare forest structure. High-severity fire effects were estimated to be reduced between 114 m and 345 m into the treated area. The range of variability in observed-distance high-severity fire effects persist into the treated area and, in conjunction with estimated relationships between posttreatment forest structure and severity, can inform the design of alternative fuel treatment prescriptions with various target prescriptions. We found that as cover was maintained in a treatment unit for wildlife habitat, the size of the fuel treatment necessary to observe a reduction in severity needs to be larger. Our study will inform decision makers on the size of treatments required to accomplish management objectives.

scholarly journals Fire and Mechanical Forest Management Treatments Support Different Portions of the Bird Community in Fire-Suppressed Forests

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 150
Author(s):  
Lance Jay Roberts ◽  
Ryan Burnett ◽  
Alissa Fogg
Keyword(s):  
Sierra Nevada ◽  
Fire Severity ◽  
Bird Species ◽  
Bird Community ◽  
Fire Disturbance ◽  
Long Term Effects ◽  
High Severity ◽  
Commercial Thinning ◽  
Silvicultural Management ◽  
Total Community

Silvicultural treatments, fire, and insect outbreaks are the primary disturbance events currently affecting forests in the Sierra Nevada Mountains of California, a region where plants and wildlife are highly adapted to a frequent-fire disturbance regime that has been suppressed for decades. Although the effects of both fire and silviculture on wildlife have been studied by many, there are few studies that directly compare their long-term effects on wildlife communities. We conducted avian point counts from 2010 to 2019 at 1987 in situ field survey locations across eight national forests and collected fire and silvicultural treatment data from 1987 to 2016, resulting in a 20-year post-disturbance chronosequence. We evaluated two categories of fire severity in comparison to silvicultural management (largely pre-commercial and commercial thinning treatments) as well as undisturbed locations to model their influences on abundances of 71 breeding bird species. More species (48% of the community) reached peak abundance at moderate-high-severity-fire locations than at low-severity fire (8%), silvicultural management (16%), or undisturbed (13%) locations. Total community abundance was highest in undisturbed dense forests as well as in the first few years after silvicultural management and lowest in the first few years after moderate-high-severity fire, then abundance in all types of disturbed habitats was similar by 10 years after disturbance. Even though the total community abundance was relatively low in moderate-high-severity-fire habitats, species diversity was the highest. Moderate-high-severity fire supported a unique portion of the avian community, while low-severity fire and silvicultural management were relatively similar. We conclude that a significant portion of the bird community in the Sierra Nevada region is dependent on moderate-high-severity fire and thus recommend that a prescribed and managed wildfire program that incorporates a variety of fire effects will best maintain biodiversity in this region.

Is the END (emulation of natural disturbance) a new beginning? A critical analysis of the use of fire regimes as the basis of forest ecosystem management with examples from the Canadian western Cordillera

2016 ◽  
Vol 24 (3) ◽  
pp. 233-243 ◽  
Author(s):  
Chris Stockdale ◽  
Mike Flannigan ◽  
Ellen Macdonald
Keyword(s):  
Forest Management ◽  
Ecosystem Management ◽  
Forest Structure ◽  
Fire Regime ◽  
Natural Disturbance ◽  
Fire Regimes ◽  
Disturbance Regime ◽  
Ecological Processes ◽  
High Severity ◽  
Management Actions

As our view of disturbances such as wildfire has shifted from prevention to recognizing their ecological necessity, so too forest management has evolved from timber-focused even-aged management to more holistic paradigms like ecosystem-based management. Emulation of natural disturbance (END) is a variant of ecosystem management that recognizes the importance of disturbance for maintaining ecological integrity. For END to be a successful model for forest management we need to describe disturbance regimes and implement management actions that emulate them, in turn achieving our objectives for forest structure and function. We review the different components of fire regimes (cause, frequency, extent, timing, and magnitude), we describe low-, mixed-, and high-severity fire regimes, and we discuss key issues related to describing these regimes. When characterizing fire regimes, different methods and spatial and temporal extents result in wide variation of estimates for different fire regime components. Comparing studies is difficult as few measure the same components; some methods are based on the assumption of a high-severity fire regime and are not suited to detecting mixed- or low-severity regimes, which are critical to END management, as this would affect retention in harvested areas. We outline some difficulties with using fire regimes as coarse filters for forest management, including (i) not fully understanding the interactions between fire and other disturbance agents, (ii) assuming that fire is strictly an exogenous disturbance agent that exerts top-down control of forest structure while ignoring numerous endogenous and bottom-up feedbacks on fire effects, and (iii) assuming by only replicating natural disturbance patterns we preserve ecological processes and vital ecosystem components. Even with a good understanding of a fire regime, we would still be challenged with choosing the temporal and spatial scope for the disturbance regime we are trying to emulate. We cannot yet define forest conditions that will arise from variations in disturbance regime; this then limits our ability to implement management actions that will achieve those conditions. We end by highlighting some important knowledge gaps about fire regimes and how the END model could be strengthened to achieve a more sustainable form of forest management.

Influence of wildfire severity on geomorphic features and riparian vegetation of forested streams of the Sierra Nevada, California, USA

2020 ◽  
Vol 29 (7) ◽  
pp. 611
Author(s):  
Breeanne K. Jackson ◽  
S. Mažeika P. Sullivan
Keyword(s):  
Sierra Nevada ◽  
Riparian Vegetation ◽  
Fire Severity ◽  
Riparian Ecosystems ◽  
High Severity ◽  
Sediment Size ◽  
Rim Fire ◽  
Geomorphic Features ◽  
Biodiversity And Ecosystem Function ◽  
Riparian Plant

Fires are a common feature of many landscapes, with numerous and complex ecological consequences. In stream ecosystems, fire can strongly influence fluvial geomorphic characteristics and riparian vegetation, which are structural components of stream–riparian ecosystems that contribute to biodiversity and ecosystem function. However, the effects of fire severity on stream–riparian ecosystems in California’s Sierra Nevada region (USA) are not well described, yet critical for effectively informing fire management and policy. At 12 stream reaches paired by fire severity (one high-severity burned, one low-severity burned), no significant differences were found in riparian plant community cover and composition or stream geomorphic characteristics 2–15 years following wildfire. In addition, minimal changes in riparian vegetation and stream geomorphic properties were observed in the first summer following the extensive and severe Rim Fire. However, an upstream-to-downstream influence of multiple fire occurrences was observed over the previous 81 years within each catchment on stream geomorphic metrics, including sediment size, embeddedness and channel geometry, at our study reaches. The inconsistent effects of wildfire on stream–riparian vegetation and geomorphic characteristics over space and time may be related to time since fire and precipitation.

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

scholarly journals Fire severity effects on soil carbon and nutrients and microbial processes in a Siberian larch forest

2018 ◽  
Vol 24 (12) ◽  
pp. 5841-5852 ◽  
Author(s):  
Sarah M. Ludwig ◽  
Heather D. Alexander ◽  
Knut Kielland ◽  
Paul J. Mann ◽  
Susan M. Natali ◽  
...  
Keyword(s):  
Soil Carbon ◽  
Fire Severity ◽  
Siberian Larch ◽  
Microbial Processes ◽  
Larch Forest

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 Relating Fire-Caused Change in Forest Structure to Remotely Sensed Estimates of Fire Severity

Fire Ecology ◽  
2016 ◽  
Vol 12 (3) ◽  
pp. 99-116 ◽  
Author(s):  
Jamie M. Lydersen ◽  
Brandon M. Collins ◽  
Jay D. Miller ◽  
Danny L. Fry ◽  
Scott L. Stephens
Keyword(s):  
Forest Structure ◽  
Fire Severity ◽  
Remotely Sensed

Mountain Ash

2015 ◽  
Author(s):  
David Lindenmayer ◽  
David Blair ◽  
Lachlan McBurney ◽  
Sam Banks
Keyword(s):  
Forest Ecosystems ◽  
Fire Severity ◽  
Fire Dynamics ◽  
High Severity ◽  
Fire Environment ◽  
Arboreal Marsupials ◽  
New Findings ◽  
Mountain Ash ◽  
Old Trees ◽  
Very High

Mountain Ash draws together exciting new findings on the effects of fire and on post-fire ecological dynamics following the 2009 wildfires in the Mountain Ash forests of the Central Highlands of Victoria. The book integrates data on forests, carbon, fire dynamics and other factors, building on 6 years of high-quality, multi-faceted research coupled with 25 years of pre-fire insights. Topics include: the unexpected effects of fires of varying severity on populations of large old trees and their implications for the dynamics of forest ecosystems; relationships between forest structure, condition and age and their impacts on fire severity; relationships between logging and fire severity; the unexpectedly low level of carbon stock losses from burned forests, including those burned at very high severity; impacts of fire at the site and landscape levels on arboreal marsupials; persistence of small mammals and birds on burned sites, including areas subject to high-severity fire, and its implications for understanding how species in this group exhibit post-fire recovery patterns. With spectacular images of the post-fire environment, Mountain Ash will be an important reference for scientists and students with interests in biodiversity, forests and fire.

Sign in / Sign up

Export Citation Format

Share Document