Growing or dormant season burns: the effects of burn season on bee and plant communities

Habitat management can play a critical role in increasing and maintaining species diversity, but timing of management techniques can have significant effects on biodiversity management. In tallgrass prairie systems, prescribed burns are a common method to promote diversity. Managers prefer winter dormant season burns but this timing differs significantly from the historic growing season burns that helped shape this community, and it is largely unexplored whether changing burn season has significant effects on higher trophic levels. Here we investigate how the timing of such burns affects the bee communities and their resources. Depending on life history traits such as above or below ground nesting, timing of fire management can have differential effects on bee diversity. In 2016 and 2017, bees were collected from prairies in south-central Illinois using active netting, pan traps, and vane traps, and measurements of plant species, flower abundance and ground cover were recorded. While both burns showed significant improvement over unburned areas, growing season burns had the greatest total bare ground area and an increase in overall bee abundances. This may suggest long term benefits of growing season burns. The results suggest that growing season burns are beneficial for bees, and the use of either burn season can be utilized for land management.