Authors: Maurer, Corina; Sutter, Louis;Martínez-Núñez, Carlos;Pellissier, Loïc;Albrecht, Matthias;

Semi-natural habitats (SNHs) provide important resources for wild bees in agricultural landscapes. As floral resources fluctuate in space and time, different SNH types within landscapes could have different effects supporting diverse bee meta-communities throughout the season. Such knowledge is of critical importance for pollinator conservation. Here, we integrate analyses of alpha- and beta-diversity, as well as species-habitat networks, to examine the relative contribution of major SNH types (extensively managed meadows, conventionally managed meadows, flower strips, hedgerows and forest edges) to wild bee meta-communities in agricultural landscapes in different seasonal periods. Results highlight the importance of extensively managed meadows supporting more rare species, habitat specialists and overall bee diversity during the entire season; yet, flower strips were similarly important in late summer. Nevertheless, each of the five investigated SNH harboured relatively unique sets of bee species, with different habitats generally acting as distinct modules in the bee-habitat network. Local floral richness explained alpha- and beta-diversity within and across habitats, while landscape composition and configuration also interactively influenced species turnover between habitats. Our findings underpin the critical importance of maintaining different types of SNH offering complementary resources throughout the season to sustain diverse meta-communities of bee pollinators in agricultural landscapes.