Post-fire Environment & Management
Major concerns after wildfires are the increased runoff and erosion due to loss of the protective forest floor layer, loss of water storage, and creation of water repellent soil conditions. To reduce the potential postfire erosion and flooding, various postfire mitigation treatments are commonly used on highly erodible areas when downstream values-at-risk are high. We have developed numerous online soil erosion prediction tools to allow for better post-fire land management decision-making. We have validated our model predictions with field studies throughout the Western US that encompass a range of rainfall regimes including monsoonal rains in the southwest (Arizona and New Mexico), thunderstorms in the Colorado Front Range and Northern Rockies, and wet frontal systems in Southern California and various erosion control treatments. For example, mulch treatments (agricultural straw, wood strands, wood shreds) reduce erosion and can be effective even for the higher intensity rainfall events. Our research results have brought a major shift in post-wildfire assessment methods and erosion management strategies.
Drought can exacerbate wildfire frequency, intensity, and severity. This webinar explores wildfire management approaches based on ecological principles, including those that embed traditional ecological knowledge.
Presenters: Dr. Jeremy Littell, Research Ecologist, Alaska Climate Adaptation Science Center, USGS
Bill Tripp, Deputy Director of Eco-Cultural Revitalization, Department of Natural Resources, Karuk Tribe
Here, we identify a north–south dipole in annual climatic moisture deficit anomalies across the Interior West of the US and characterize its influence on forest recovery from fire. We use annually resolved establishment models from dendrochronological records to correlate this climatic dipole with short-term postfire juvenile recruitment. We also examine longer-term recovery trajectories using Forest Inventory and Analysis data from 989 burned plots. We show that annual postfire ponderosa pine recruitment probabilities in the northern Rocky Mountains (NR) and the southwestern US (SW) track the strength of the dipole, while declining overall due to increasing aridity. This indicates that divergent recovery trajectories may be triggered concurrently across large spatial scales: favorable conditions in the SW can correspond to drought in the NR that inhibits ponderosa pine establishment, and vice versa. The imprint of this climatic dipole is manifest for years postfire, as evidenced by dampened long-term likelihoods of juvenile ponderosa pine presence in areas that experienced postfire drought. These findings underscore the importance of climatic variability at multiple spatiotemporal scales in driving cross-regional patterns of forest recovery and have implications for understanding ecosystem transformations and species range dynamics under global change.
This study used a value of information approach to demonstrate the cost-effectiveness of using satellite imagery as part of the Burn Area Emergency Response (BAER), a US federal program that identifies imminent post-wildfire threats to human life and safety, property and critical natural or cultural resources. It compared the costs associated with producing a Burn Area Reflectance Classification map and implementing a BAER when imagery from satellites (either Landsat or a commercial satellite) was available to when the response team relied on information collected solely by aerial reconnaissance. The case study included two evaluations with and without Burn Area Reflectance Classification products: (a) savings of up to US$51 000 for the Elk Complex wildfire incident request and (b) savings of a multi-incident map production program. Landsat is the most cost-effective way to input burn severity information into the BAER program, with savings of up to US$35 million over a 5-year period.
View research brief.
Ecosystems worldwide are facing complex interacting stressors that are leading to rapid and potentially irreversible change. Many of these changes involve vegetation type-conversion in various stages and forms. A variety of terms are applied to changes in ecosystems around the world to describe some aspect of long-lasting changes in plant communities. Here we evaluate a representative list of analogous terms for processes and patterns involved in vegetation type-conversion, highlighting similarities and differences. The list illustrates a common problem in ecology, viz. how similar terminology may actually describe different aspects of complex processes. Linking this terminology under a unified, umbrella concept of vegetation type conversion and placing it into the context of an ecological resilience framework, including community reorganization, may help resolve research agendas and conservation efforts.
Across the western US, severe wildfires fueled by tinder-dry vegetation have already burned more than 3.2 million hectares (8 million acres) — an area the size of Maryland — as of the end of October, 2020, and nearly six times that area burned this year in Australia. And even though neither country’s worst-ever fire year is not yet over, concerns are already mounting regarding the next hazard these regions will face: dangerous and destructive debris flows.
Approximately 75% of models tested had acceptable, excellent, or outstanding predictive ability. The models that performed poorly were primarily models predicting stem mortality of angiosperms or tree mortality of thin-barked conifers. This suggests that different approaches—such as different model forms, better estimates of bark thickness, and additional predictors—may be warranted for these taxa. Future data collection and research should target the geographical and taxonomic data gaps and poorly performing models identified in this study. Our evaluation of post-fire tree mortality models is the most comprehensive effort to date and allows users to have a clear understanding of the expected accuracy in predicting tree death from fire for 44 species.
This study’s objective was to determine whether remnant/unburned sagebrush patches contribute to sagebrush recovery in surrounding burned areas surrounding them.
While conventional wisdom is that sagebrush seeds remain close to the mother plant, we found that a measurable percentage of seeds travel up to tens of meters. Remnant patches of sagebrush after fire could contribute to natural regeneration in surrounding landscapes. However, seed arrival was highly variable between sites and work remains to be done to predict where natural regeneration will be sufficient to rehabilitate sagebrush steppe after wildfire.
Description: Landscapes of the Inland West are deeply affected by 100+ years of fire exclusion, the loss of indigenous burning, and expansion and densification of many forests. Today, anthropogenic climate change and wildfires are modifying the structure and composition of forests across the West at rates that far exceed adaptation and restorative treatments. Fires that occur during the forest planning process can delay project implementation for years, further hindering the pace of restoration activities. Landscape evaluations and prescriptions are needed so that managers can assess the work of wildfires on affected landscapes; the topic of this webinar.
Presenters and research team: Andrew Larson, C. Alina Cansler, Derek Churchill, Paul Hessburg Sr., Sean Jeronimo, Van Kane, Jim Lutz, and Nicholas Povak.
This wildfire recovery graphic and facilitator’s guide were developed by FAC Net practitioners to address the diversity of community and landscape needs after wildfire and to provide a common framework for post-fire discussions. The graphic, by practitioners and for practitioners, integrates experiential knowledge from diverse communities, ecosystems, and perspectives.