Does Landscape Structure Affect the Presence of Woodland Specialist Pollinators in Farmland? Implications for Agri-Environment Scheme Design

Abstract

Some pollinator species found in agricultural areas are strongly dependent on surrounding areas of natural or semi-natural habitats to nest and/or forage. Landscape structure has been shown to influence pollinator communities and understanding how landscape structure affects farmland pollinators can improve Agri-Environment Schemes (AES). This study explored how landscape metrics affect the presence of pollinators associated with woody vegetation in farmland in the Republic of Ireland. Two study regions were selected, and pollinators were collected using pan traps placed in farm linear features. Hoverfly and bee species were selected based on their body size and association with woody vegetation. Relevant landscape structure metrics were extracted from around each trap and used to develop explanatory models for the abundance of pollinators. The total abundance of target species was relatively low but correlated with three explanatory variables: the connectivity of the linear feature to woodlands; the distance from the trap to the closest woodland; and edge density. Hoverfly and bee abundance data, when analysed separately, showed significant differences within regions. Results seem to indicate that incentivising the connectivity of farm linear features to surrounding woodland patches and increasing optimal habitat availability in agricultural landscapes could benefit woodland specialists. This information is helpful to improving AES design.