Five-year impact of prescribed burning and wildflower seeding on Lepidoptera communities in the U.S. Southern Great Plains

Prescribed burning and seeding are often used to reduce wildfire risk, manage invasive plants, and promote native plant communities. However, the potential benefit of these management practices on Lepidoptera communities has received less attention, especially across multiple years post-treatment. We investigated the impact of prescribed fire and wildflower seeding treatments on Lepidoptera communities in the five years following an administered burn. Specifically, we established 33 study plots across the Cross Timbers region of Texas and Oklahoma to evaluate the impact of three treatment types – a 5-acre burn, a 5-acre burn with subsequent wildflower seeding, and a non-burned control – on Lepidoptera abundance and species richness. We also explored the influence of floral resources (abundance and species richness), ground cover, landscape-level grassland cover, and water resources (30-day precipitation and available water) on the Lepidopteran community. We found that Lepidoptera abundance and richness followed a hump-shaped curve across all treatments, increasing in the years immediately following treatment before decreasing back to pre-treatment levels. We found a significant interaction between treatment type and time since implementation, where Lepidopteran abundance and richness increased and then decreased the most for the 5-acre burn. Regardless of treatment, floral abundance and landscape-level grassland cover were positive predictors of Lepidoptera abundance and species richness. Overall, our results reveal high year-to-year variation in the Lepidoptera community and show that land management practices which improve floral resources can indeed support high Lepidoptera abundance and richness.