The Importance of Multiscale Spatial Heterogeneity in Wildland Fire Management and Research

Abstract

The occurrence and effects of fire vary greatly over multiple spatial and temporal scales. At a regional scale, variation in synoptic climate and associated vegetation characteristics results in diverse fire regimes, ranging from systems having frequent, low-severity fires (e.g., pine forests of the southwestern and southeastern United States) to systems characterized by infrequent but stand-replacing fires (e.g., subalpine and boreal forests of North America). At a finer scale, spatial variability in fuel mass and structure may influence fire ignition and severity under a middle range of weather conditions, but effects of fuels may be overwhelmed by effects of extreme weather either extremely wet (no fire) or extremely dry and windy (large, severe fires). Almost all fire events exhibit a heterogeneous pattern of burning and create a mosaic of fire severity within the burned area, resulting in spatially variable changes in plant community structure, soil characteristics, and ecosystem processes of energy and biogeochemistry. We have a pressing need to better incorporate our understanding of spatial heterogeneity into wildland fire policy and management and to address urgent research questions about spatial patterns in fire history, fire effects, and responses of organisms and ecosystems to the spatial variability of fire.