Configuration optimization of conservation easements for native bee pollination services: preliminary results of soybean yield impacts

USDA Conservation Reserve Program easements cover approximately 22 million acres across the United States and typically are conserved for ecosystem service provision in agricultural landscapes. Though many of these conservation easements are focused on hydrological and nutrient mitigation support, there is a significant portion of easements that are primarily for habitat provision, including pollinator support (approximately 1.6 million acres of potential pollinator habitat). However, even those easements that are not necessarily created for pollination services can provide pollination service support as a co-benefit and as non-traditional habitat for pollinators. Building on results from prior modeling and field studies in the Mid-Atlantic region, we explore the potential of utilizing current private conservation land as habitat patches for native bee pollinator support, using soybean yield as a native bee crop pollination service indicator and marketable ecosystem service. Using the novel USDA private land conservation geodatabase and Stanford University’s InVEST crop pollination model, we explore the effects of different habitat patch size, shape, and frequency on soybean pollination ecosystem services. We assess the most common Conservation Reserve Program practices, regardless of listing as potential pollinator habitat or not, in both the Midwest Corn Belt and the Mid-Atlantic region in the United States, comparing how different configurations can potentially affect soybean yield, pollinator foraging and nesting, and pollinator abundance. In addition, determining the relative importance of foraging and nesting limitation in agricultural landscapes to characterize both marketable (soybean yield) and non-marketable (pollinator abundance and resource sustainability) ecosystem services for native bee communities.