Patch-Burn Grazing is Similar to Annual Burning in Effects on Belowground Invertebrates in Tallgrass Prairie

Abstract

Patch-Burn Grazing (PBG) is a rangeland management strategy that aims to promote heterogeneity across a landscape by burning rotating discrete patches of land, which draws cattle to the most recently burned areas. This is in contrast to Annual-Burn Grazing (ABG), which is a commonly used management practice across the rangelands of the midwestern United States that tends to homogenize the grazing landscape. PBG has been thought to promote biodiversity of a variety of taxa, including birds, small mammals, and plants. However, the impacts of PBG on invertebrate communities are not well understood. Here we investigate the effects of these alternative fire-grazing management strategies on soil-dwelling invertebrate communities in a tallgrass prairie rangeland ecosystem. Specifically, we examine the effects of each management style on overall biodiversity and variability of belowground invertebrates across the landscape, as well as the responses within individual burn areas of PBG. We found that soil-dwelling invertebrate richness at the plot-scale was higher in ABG compared to PBG, while community composition and abundance did not differ between the two management methods. Additionally, richness, evenness, and abundance of belowground invertebrates did not differ across the PBG landscape based on years since burning. Finally, beta-diversity of belowground invertebrates across the landscape did not differ between PBG and ABG. Overall, our results suggest that PBG does not differ from ABG in its impact on biodiversity in belowground invertebrate communities. Further research investigating why some taxa (e.g., birds, small mammals) respond differently than others (e.g., belowground invertebrates) would help inform land management decisions across the region. Understanding these dynamics expands our insights surrounding how heterogeneity driven by fire-grazing interactions impacts rangeland invertebrates.