Synopsis:
Researchers analyzed variation in crop pollination services provided by native, unmanaged, bee communities on organic and conventional farms situated along a gradient of isolation from natural habitat. Pollination services from native bees were significantly, positively related to the proportion of upland natural habitat in the vicinity of farm sites, but not to any other factor studied, including farm type, insecticide usage, field size and honeybee abundance. The scale of this relationship matched bee foraging ranges. Stability and predictability of pollination services also increased with increasing natural habitat area. This strong relationship between natural habitat area and pollination services was robust over space and time, allowing prediction of the area needed to produce a given level of pollination services by wild bees within the landscape. Crop pollination services provided by native bee communities in California strongly depended on the proportion of natural upland habitat within 1–2.5 km of the farm site, a spatial scale that accords well with maximal foraging distances for similar bee species. This predictive relationship between habitat area and pollination services could allow land-use planners to establish conservation targets in this landscape. Targets are commonly applied in planning networks of protected areas to conserve biodiversity.
Conclusions:
Pollination services from native bees were significantly, positively related to the proportion of upland natural habitat in the vicinity of farm sites.
Thresholds/Learnings:
Crop pollination services provided by native bee communities in California strongly depended on the proportion of natural upland habitat within 1000–2500m of the farm site, a spatial scale that accords well with maximal foraging distances for similar bee species.
