Different semi-natural habitat types provide complementary nesting resources for wild bees

Semi-natural habitats provide refuge for pollinating insects such as wild bees. Different types of semi-natural habitat can provide complementary floral resources throughout the year, but it is uncertain to what extent different semi-natural habitat types provide nesting habitat for wild bees. In this study, nesting resources for wild bees and nest-searching bees were surveyed visually in three different types of semi-natural habitat (i.e., hollow roads, tree rows, and forest edges). The composition of nesting resources for wild bees varied across the three types of semi-natural habitat. We also identified clear indicators of nesting resources within the different habitat types. We conclude that different types of semi-natural habitat provide varying and complementary nesting resources for wild bees. This study further highlights the importance of semi-natural habitat for pollinator conservation and emphasizes the need for further research to increase our understanding how different wild bee species use different habitat types for nesting.