OREGON STATE UNIVERSITY

Fire refugia

Wildfire refugia in forest ecosystems of northwestern North America: predictability, form, and function

 

Collaborators: Sandra Haire, Meg Krawchuk, Jonathan Coop, Carol Miller, Marc-Andre Parisien, Ellen Whitman, Geneva Chong, Will Downing, Ryan Walker, Garrett Meigs

 

Overview: Wildfires are familiar landscape disturbances in forested ecosystems of western Canada and the United States that result in mosaics of fire effects. The concept of burn severity is used to quantify biological, physical, and chemical effects of fire, and can be broadly defined as the degree to which an ecosystem changes as a result of fire. Landscape heterogeneity produced by burning, which can include a range in severity from unburned patches to high severity fire, is important to conserving characteristic biodiversity of fire-adapted ecosystems. As a part of the burn mosaic, areas that experience comparatively low-severity fire or remain unburned are landscape legacies that can provide an essential environment for species sensitive to fire, and support populations that contribute to the reassembly of biotic communities after fire. Fire islands, residuals, remnants, skips, shadows, refuges, refugia, or unburned patches are all terms used to describe areas at the low end of the burn severity spectrum. Here, we use the term fire refugia to describe places that are disturbed less frequently or less severely by wildfire than the surrounding landscape matrix. Refugia can exist at a range of spatial scales, e.g., from an individual plant or small patch of vegetation to broader landscapes. And refugia can occur across a range of temporal scales, persisting only in the short term through a single fire event or in the longer-term through multiple events. The term fire refugia is adapted from the broader concept of refugia as places providing environmental stability and facilitating species persistence as regional biotic and abiotic environments change. An understanding of the processes and patterns of fire refugia formation, maintenance, and ecosystem role across multiple spatial and temporal scales is critical as we (society) strive(s) to meet landscape fire management and ecosystem restoration goals, now and into the future.

Our research on wildfire refugia is anchored in understanding burn mosaics, how they form, and the ecological implication of the complicated patterns that result.

Our ongoing research can generally be divvied up into two project arms:

  1. Advancing our understanding of the biophysical factors that generate fire refugia, with a focus on the role of topography and fire weather
  2. Digging in to examine the ecological form and function of fire refugia, both in the field and based on existing data archives (https://www.researchgate.net/project/Ecological-function-of-forest-wildfire-refugia)