Landscape Ecology 2005 (in press).

Butet, A.,  Paillat, G. & Delettre, Y. 

Factors driving small mammal assemblages from field boundaries 

in agricultural landscapes of Western France.

Abstract :

In this study, we investigated the factors that are driving diversity and abundance of small mammal species inhabiting permanent linear habitat patches within high intensified agricultural landscapes of western France. Multivariate (co-inertia) analysis was used to analyze relationships of habitat and landscape descriptive variables with faunal records. Two main ecological gradients were recognized according to statistical analysis and  relationships of species occurrence with environmental factors were interpreted according to their main life traits. The first ecological gradient clearly differentiates communities from hedges to those of grass-dominated linear banks. This first gradient was respectively associated with the prevalence of forest versus grassland rodent species but shrew species didn’t show any link with it. This partitioning seems to reflect rather ecological requirements of species than competitive interactions. Small mammals 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 small mammal biomass for predators.

Key-words : Agricultural landscape, Small mammal community,  diversity, multivariate analysis, France