2021 ESA Annual Meeting (August 2 - 6)

Restoring ecological processes after wildfire: The key to contemporary forest management in an era of global change?

On Demand
Elizabeth K. Swanson, Forest Ecosystems and Society, Oregon State University;
Background/Question/Methods

Wildfire area burned has increased dramatically in the western United States and this trend is expected to continue (Rogers et al., 2011), as increasing drought (Holden et al., 2018) and temperature generate optimal conditions for fire activity (Westerling, 2016). The interaction of fire and climate is expected to have profound effects on vegetation across the globe (Turner, 2010) including Pacific Northwest (PNW) forests in the coming decades (J. E. Halofsky et al., 2020). Post-fire forest conversion is highly problematic in the West where forests provide important habitat and refuge for many species. Recent research has revealed several important principles to guide restoration after fire, however gaps remain in our understanding of restoring forest resilience after fire, particularly in light of increasing extremes in environmental conditions which generate the potential for further disturbance. In this study, we ask the following questions: (1) how do we define success and resilience in restoration after fire? (2) What are barriers to achieving success in post-fire restoration and how do we best overcome these? (3) What ecological processes are most important to restore for resilience to future disturbance? We used a synthetic approach to identify explicit challenges to restoring forest resilience after wildfire.

Results/Conclusions

Our synthesis found that the primary challenges to successful post-fire restoration are: severe reburn potential resulting in a lack of seed sources necessary for regeneration, mortality bottleneck in the establishment phase due to biotic and abiotic pressure, and large increases in weed species that alter the fire regime of the region and generate negative feedback loops. We found that restoring a few key ecological processes can greatly enhance the success of post-fire forest restoration. These processes include: fire, reproduction, dispersal dynamics, soil-water relations and assembly driven biotic interaction. We offer a conceptual model and several novel principles that can be incorporated into forest management practices to address these challenges, amplify restoration success and achieve resilience to future disturbance.