Conserving and restoring pollination services in organic farms of Yolo and Solano Counties, Northern California

Native bee pollinators link natural habitats with agricultural areas. Native bee populations may rely on natural habitats to provide forage and nesting resources during part of the year, and agricultural areas the rest of the year. Native bee pollinators may provide pollination services in both areas, and may in turn depend on both. Thus problems in one area could affect the other. For example, if natural areas suffer a reduction in pollination services due to declining populations of native bees, some native plants would fail to reproduce, further impoverishing natural areas already declining in species diversity and abundance due to habitat fragmentation and degradation. This in turn will diminish the abundance of forage available for bees in the following year, potentially reducing bee populations available to provide pollination services to crops.

Understanding the contributions of native bees to agriculture, and the dependence of native bees on both natural and agricultural habitat, will help us to develop plans for managing and conserving the pollination services they provide.

In our two-year study on various crops in Yolo County, we have been documenting:

• the role of native bees in crop pollination

• the role of natural areas in maintaining bee abundance, diversity and pollination services

• the economic value of native bees as crop pollinators

• the role of land management practices in enhancing pollination services on farms