Quantitative evaluation of the efficacy of prairie conservation grasslands for native pollinator biodiversity in intensive agriculture

The USDA Conservation Reserve Program (CRP) was initiated in 1985 as an incentive to preserve environmentally sensitive lands in regions of intensive agriculture for the benefit of soil, water, or wildlife. Each CRP type specifies management guidelines based on a specific conservation target and can dictate the use of specific seed mixes to ensure proper plant communities, how seeds are planted, and whether the habitat is mown or burned and at what frequency. In 2008, the program was expanded to include guidelines for insect pollinator conservation. As of 2019, over 500,000 acres have been enrolled nationally and over 5,000 acres contracted across Indiana. However, despite being widely implemented, there has yet to be a substantive quantitative review of the efficacy of flowering plant management procedures or habitat benefits for pollinators. To address this gap, we used active (sweep net) and passive (bee bowl) methods to survey insects from pollinator-specific and general wildlife habitats between June and October 2020, and used these collections to compare pollinator diversity within and between CRP types. We also cataloged flowering plant diversity once per month, and correlated forb community diversity with pollinator diversity. Our data demonstrate how plant community varies within and between management types and how this, in turn, affects pollinator community. This research addresses the current shortcomings in basic knowledge of the functioning of these conservation habitats and will ultimately contribute to improving CRP management guidelines for the benefit of pollinators, CRP administrators, and farmers