The Role of Uncultivated Habitats in Supporting Wild Bee Communities in Mediterranean Agricultural Landscapes

In agricultural landscapes, uncultivated habitat patches may have a focal role in supporting communities of ecosystem service providers. However, little is known on the variances among different types of uncultivated habitat patches in providing resources and maintaining populations of these beneficial organisms. We studied wild bee communities in natural and semi-natural uncultivated patches embedded in semi-arid Mediterranean agricultural landscapes. We investigated the effects of local- and landscape-scale land-use characteristics, as well as their interactions, on bee diversity, functional composition, and forage and nesting resources. Most bee community parameters were affected by both local- and landscape-scale characteristics, but no significant interactions were found among the scales. Local land-use effects were related primarily to overall plant cover, and to the abundance and richness of flowering plants. Landscape effects, mostly limited to a 400 m range, were varied. The abundance of focal crop pollinators varied considerably between patch type and pollinator species. The different types of uncultivated habitats maintain complementary bee and flower communities. Our findings show the important role of uncultivated habitat patches in providing floral and nesting resources for bees, and creating resource-landscapes that can support wild bee communities and crop pollination services in Mediterranean agricultural landscapes.

Automated summary

Uncultivated habitat patches in agricultural landscapes play a crucial role in supporting communities of ecosystem service providers, specifically wild bees. However, little is known about the differences among various types of uncultivated habitat patches in terms of resource provision and population maintenance of these beneficial organisms. Our study in Mediterranean agricultural landscapes revealed that both local and landscape factors influenced the diversity, functional composition, and availability of forage and nesting resources for bees. The different types of uncultivated habitats maintained complementary bee and flower communities, and were essential for supporting wild bee communities and crop pollination services.