Landscape diversity moderates the effects of bee visitation frequency to flowers on crop production.

1.Reductions in natural habitat are implicated in declining honey bee Apis mellifera L. and wild bee populations, thereby threatening crop production. This concern has stimulated interest in identifying landscape-level impacts on bee-mediated pollination services, but previous studies have only inferred connections between landscape, bees and yield through generalized linear regressions. 2. We examined landscape impacts on bee-mediated crop yield using both a traditional linear regression approach and conditional process modelling, which combined landscape features, bee visits to crop flowers, interactions between landscape and bee visits to flowers into a single model predicting crop yield. We used the pumpkin Cucurbita pepo L. system in New York State and recorded bees visiting pumpkin flowers in 2011 and 2012. Landscape diversity and percentage of semi-natural grassland around each pumpkin field were calculated. 3. Results from the traditional approach indicated that landscape divers...