Taxonomic and Functional Community Composition of Ground Beetles (Coleoptera: Carabidae) Changes with Prescribed Fire Severity

Abstract

Prescribed fire is a conservation management tool that is frequently used to foster biodiversity by attempting to mimic historic wildfire regimes, reduce invasive species, and maintain habitat integrity. Simultaneously, insects that provide essential ecosystem services such as decomposition, nutrient cycling, and pest control, are globally declining. Within the pyroentomology literature there are mixed reports of positive and negative effects that prescribed fires have on insect communities. This is likely due to generalizing prescribed fires and not accounting for fire heterogeneity created by the fire characteristics such as fire severity. To better understand if prescribed fire severity can affect insect communities, we used multispectral reflectance data collected by Sentinel-2 to methodically quantify prescribed fire severity and compared ground beetle (Coleoptera: Carabidae) taxonomic and functional community composition responses between an unburned site and two sites burned with contrasting fire impacts. We found 23 ground beetle species and used 30 morphological, physiological, phenological, and ecological functional traits for each species. We found that our moderate fire severity site had different taxonomic and functional community compositions from both our unburned and high severity site. Surprisingly, we did not find a strong difference in taxonomic or functional ground beetle composition between our unburned and high severity site. Thus, we provide support that prescribed fire severity does affect ground beetle community composition and encourage future pyroentomology studies to account for fire severity which will help guide conservation managers to make more accurate decisions and predictions about prescribed fire effects on biodiversity in our native landscapes.