Responses from bees, butterflies, and ground beetles to different fire and site characteristics: A global meta-analysis

Climate change in concert with fire suppression is increasing the size, severity and frequency of fires globally. At the same time, insects, an exceptionally biodiverse group that provide essential ecosystem services such as pollination and decomposition, are declining precipitously. We know little, however, about the fire mechanisms that contribute to insect decline. To understand if there is a larger global signature of fire on insect communities, we conducted a global systematic search and meta-analyses on the pyroentomology literature for butterflies (Lepidoptera: Rhopalocera), bees (Hymenoptera: Apoidea), and ground beetles (Coleoptera: Carabidae) and report how each taxa's richness and abundance response to overall fire, 16 different fire and site characteristics, as well as fire combined with forest/grassland management treatments. Across 100 studies and 445 effects, we found that bee biodiversity increased after fire and fire in combination with forest/grassland management treatments. In contrast, fire had no significant positive or negative effect on ground beetle and butterfly biodiversity. Furthermore, we did not find any fire and site characteristics that decreased richness across our taxa. Surprisingly, we found that only 7% of the studies quantified fire severity, which likely explains the inconsistent results within the pyroentomology literature. We conclude that further consideration of fire mechanisms will advance our understanding of how insects respond to fires. Our findings on how each taxa's richness and abundance respond to each fire and site characteristic will create a stronger foundation to help scientists and conservation managers make better decisions and predictions to achieve their research and management goals.

Automated summary

The study found that bee biodiversity increases after fire and fire in combination with forest/grassland management treatments, while ground beetle and butterfly biodiversity are not significantly affected. Additionally, only a small percentage of studies quantified fire severity, likely contributing to inconsistent results within the pyroentomology literature.