Re-establishing pollinator communities and pollination services with hedgerow restoration in intensive agricultural landscapes

Declines of managed and native pollinators are causing concern world-wide.  Restoration of small habitat areas, such as hedgerows, in intense agricultural landscapes is being increasingly encouraged and is a feasible method for growers to implement conservation on their lands.  However, little is known about whether small-scale restoration in intensive agricultural landscapes will benefit native pollinator populations.  In the Central Valley of California, we are comparing native bee populations and pollination services on sites with and without native perennial plant hedgerows.  We questioned whether hedgerows are increasing abundance of native bees and if they differentially impact common and less common species.  We assessed whether hedgerows were net exporters or concentrators of pollinators and how hedgerows impact pollination services to adjacent crops.  We found that hedgerows did not increase overall bee abundance but did increase abundance of all but the most common species.  Hedgerows also increased species richness and acted as net exporters to adjacent fields.  We also are assessing economic costs and benefits of hedgerow restoration to agricultural production.