Prescribed Burning Alters Insects and Wood Decay in a Sagebrush-Steppe Rangeland in Southwestern Idaho, United States

Document Type

Article

Publication Date

9-2023

Department

College of Forest Resources and Environmental Science

Abstract

Prescribed fall burning is commonly used worldwide on rangeland sites to enhance vegetation resources and restore disturbed ecosystems, but little is known about how it may alter microbial communities and insect activities. We used two site treatments (low- to moderate-burn severity plots and unburned control plots) at a high-elevation (2 100 m above sea level) shrub-steppe rangeland site. Four yr after the prescribed burn, captured insects primarily consisted of Coleoptera (beetles), Hymenoptera (ants, bees, and wasps), and Orthoptera (grasshoppers and crickets) species with similar or greater numbers captured on burned plots as compared with unburned plots. We used wood stakes to assess microbial population changes. Aspen (Populus tremuloides Michx.) and pine (Pinus taeda L.) wood stakes were placed horizontally on the soil surface and vertically into the mineral to determine microbially altered wood decay rates. In mineral soil, mass loss (wood decay) of both aspen and pine increased significantly in the burned plots after 5 yr. Surface aspen also had increased decay in the burned plots, but pine surface stakes were unaffected. Surprisingly, at this high-elevation site we also found subterranean termites (Reticulitermes tibialis Banks) feeding on both stake species, with greater numbers on aspen stakes in burned plots leading to greater wood mass loss and organic matter turnover rates. Our results suggest that that fall prescribed burning can enhance insect numbers and microbial decay in sagebrush-steppe ecosystems. Understanding these changes can help land managers predict the influence of fall prescribed burning operations on soil biological properties and insect communities.

Publication Title

Rangeland Ecology and Management

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