Spatial and temporal variation in pollinator community structure relative to a woodland-almond plantation edge

Abstract

Agricultural landscape elements, such as field edges, are not always a barrier to insects but can influence their distribution and dispersal behaviour. The present study investigated spatial and temporal patterns in wild pollinator (fly, wasp and non-Apis bee) distribution across an edge between natural mallee woodland and monoculture almond plantations in southern Australia, during the critical almond flowering period. This is the first study of variation in pollinator community distribution on both sides of an edge between natural vegetation and flowering tree crop plantations. Species richness, diversity and evenness (SHE) analysis was also used to identify changes in pollinator community structure relative to the edge. It is shown that the spatial distribution and structure of pollinator communities can vary across a habitat edge with an abrupt temporal changes in resources. Our results suggest that the plantation edge did not prevent wild pollinators spilling over from woodlands, although vegetation homogeneity and phenological changes in resources most likely influenced the dispersal of pollinators into plantation interiors. The findings of the present study contribute to our knowledge of edge responses by insects in managed landscapes and could motivate growers to adopt ecological management practices in commercial plantations. Future studies of insects near farmland edges should include samples on both sides of the edge and should also consider the landscape context.