Factors driving small rodents assemblages from field boundaries in agricultural landscapes of western France

In this study, we investigated the factors driving diversity and abundance of small rodent species inhabiting permanent linear habitat patches within high-intensified agricultural landscapes of western France. Multivariate (co-inertia) analysis was used to analyse relationships of habitat and landscape descriptive variables with rodent records. Two main ecological gradients were recognized according to statistical analysis. Relationships of species occurrence with environmental factors were interpreted according to their main life traits. The first ecological gradient clearly differentiated communities from hedges to those of grass-dominated linear banks. This first gradient was associated with the prevalence of forest versus grassland rodent species. This partitioning seems to reflect rather ecological requirements of species than competitive interactions. Small rodents diversity and abundance were inversely evolving along this gradient. The second factor influencing species assemblages was associated to landscape heterogeneity surrounding the permanent habitats. According to this second gradient, species seemed to be selected in relation to their ability to disperse and to use cultivated fields. Maximum diversity was generally observed in heterogeneous permanent habitats with mixed vegetation structure but hedges are important to produce biomass for predators.