Spatial analysis of the potential exposure of amphibians to plant protection products at the landscape scale

Plant protection products (PPPs) are among the many drivers that lead to the loss of biodiversity in agricultural landscapes and they are a contributing factor to the global decline of amphibians. The aim of the present study is to estimate the potential exposure of amphibian population networks to PPPs. Specifically, our goal is to describe the spatial overlap of amphibian population networks with agricultural crops where PPPs are potentially used. We estimate terrestrial habitat suitability for eleven amphibian species using a multi-scale species distribution modelling approach. Using the suitability maps as the basis for estimating landscape resistance, we then calculate potential dispersal corridors between known breeding sites for each species. Where available, we use local landscape genetic studies from the literature to validate and select the most appropriate resistance model for each species. By comparing the locations of suitable habitat and dispersal corridors with a parcel-scale database on agricultural land-use, we locate and quantify potential hotspots for PPP-exposure within the core habitat around each species' breeding sites and along the movement routes between them. By highlighting differences among species, we identify species which are particularly at risk of exposure and gain insight into the mechanisms with which PPPs in terrestrial habitats may potentially influence these networks. Together, the maps provide policy makers with a flexible tool that can identify and prioritize regions for the implementation of locally adapted management strategies.