Evaluating best management practices for pollinator plantings in the southeastern USA

Abstract

Recent bee declines highlight the importance of bee conservation efforts, including planting wildflower meadows for pollinators. Pollinator plantings require management to maintain a high abundance and diversity of blooms for foraging bees. However, it is unknown how flowering resources and bee resource use differ among plantings with different management strategies. In this thesis, I explored both mechanical strategies and soil amendments for wildflower planting management. In chapter 2, I compared wildflower and bee assemblages in plantings receiving no management against commonly employed annual mechanical techniques: mowing, disking, or a combination of both over three years. I found that no management was comparable to annual mechanical techniques in bloom and bee density and richness, highlighting that management frequency could be reduced to save time and effort of landowners. I also compared treatments with a third-year prescribed burn, finding few differences except in presence of non-planted woody species. In chapter 3, I tested the effects of biochar, a high-carbon soil amendment, on soil characteristics and on density, diversity, and composition of planted wildflowers and bees. I found few differences between biochar and control treatments except for an increase in soil cation exchange capacity in biochar amended soils and per-species differences in density for two wildflower species and one bee species. The lack of overall differences in wildflowers or bees points to a need for further research investigating the applicability of biochar for pollinator plantings.