Zachary Bunch

and 5 more

Landscape heterogeneity is widely recognized as a driver of biodiversity, yet its ecological consequences for insect communities under active grassland management remain underexplored. Patch-burn grazing (PBG), which rotates fire across patches within a grazed landscape, is designed to promote spatial and temporal heterogeneity by creating a shifting mosaic of successional stages. In contrast, annual burning and grazing (ABG) imposes uniform disturbance. We tested how these contrasting strategies shape aboveground invertebrate communities across three years (2021-2023) in tallgrass prairie at the Konza Prairie Biological Station in Manhattan, Kansas. Using vacuum sampling, we quantified family-level richness, evenness, abundance, functional group composition of aboveground invertebrates, and herbivory across PBG and ABG units. Contrary to expectations, PBG did not consistently enhance local (alpha) or beta-diversity. Insect richness was higher in ABG in one year, while evenness was greater in PBG in another. Total abundances and functional group distributions were broadly similar, with only limited treatment differences. However, PBG significantly altered invertebrate community composition in two of three years, suggesting that heterogeneity influenced community structuring, even when richness was unchanged. Herbivory rates did not differ between treatments. Our findings reveal that using PBG to manage spatial heterogeneity leads to complex responses in insect communities but may lead to distinct community compositions across the landscape. This decoupling of richness from composition highlights the importance of considering multiple biodiversity metrics when evaluating ecological outcomes. By fostering compositional variability without inflating herbivore pressure, PBG has potential as a heterogeneity-based strategy for managing grasslands.