Flowering cover crops as an early-season floral resource for native bees in Pennsylvania agroecosystems
Open Access
- Author:
- Ellis, Katherine Elizabeth
- Graduate Program:
- Entomology
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- December 09, 2013
- Committee Members:
- Mary Ellen Barbercheck, Thesis Advisor/Co-Advisor
- Keywords:
- pollinators
native bees
cover crops
conservation
agriculture - Abstract:
- Conservation of natural processes such as pollination, pest control, and nutrient cycling are essential to maintaining a healthy agroecosystem. The incorporation of cover crops into annual crop rotations is one practice that is used in the Northeast U.S. to manage soil fertility, weed suppression, and erosion control. Additionally, cover crops that have a flowering stage have the potential to support beneficial insect communities, such as native bees. Because of the current decline facing managed honey bee colonies, the conservation of native bee communities is critical to maintaining ‘free’ pollination services. However, native bees are negatively affected by agricultural intensification and are in decline across North America. This project assesses the potential of flowering cover crop species to act as a conservation resource for native bee communities, in addition to providing benefits to soil fertility and agricultural production. Three flowering cover crop species are evaluated here across various crop rotation schedules and at differing levels of cover crop diversity. Flowering resources were monitored for each of these studies along with native bee and Syrphidae fly visitation. In conclusion, cover crop species selection, cash crop rotation schedule and plant diversity level all had significant influence on the floral resources available to the native pollinator community. Different cover crop species not only had different blooming schedules and winter survival responses to planting date, but attracted unique native bee communities to their available floral resources. Additionally, flower density was shown to be the driving factor influencing differences in bee visitation frequency across treatments, but within cover crop species, for both the plant diversity and fall planting date experiments. The results from these experiments should be influential in informing future conservation and grower extension recommendations on the applied use of flowering cover crops for pollinator conservation purposes in Pennsylvania annual cropping systems.