Linear woodlots increase wild bee abundance by providing additional food sources in an agricultural landscape

Abstract

Mid-field woodlots play an important role in maintaining biodiversity in agricultural landscapes. However, it is not clear whether non-linear or linear woodlots are most beneficial for wild bee conservation. We assessed the attractiveness of two common types of woodlots in an agricultural landscape in northern Poland (non-linear and linear: 7 and 9 sites, respectively) in terms of wild bee abundance, species richness, and functional diversity. Linear habitats had higher abundance of wild bees. However, woodlot type did not affect wild bee species composition or functional trait composition. Species composition responded significantly to measures of syntaxonomic heterogeneity and landscape heterogeneity. Woodlot area, landscape context (isolation and landscape heterogeneity), and syntaxonomic heterogeneity explained most of the differences among habitats (non-linear vs. linear) in wild bee abundance and species richness, regardless of the habitat type. The higher attractiveness of linear woodlots was due to increased food availability in the herbaceous layer in the spring–summer (June) and summer (July–August) periods. Linear woodlots have the potential to be used as tools for integrating agricultural production with biodiversity conservation and ecosystem services.