Impact of different agricultural practices on the genetic structure of Lumbricus terrestris, Arion lusitanicus and Microtus arvalis

Little attention has been given to date to the potential influence of agricultural land use methods or farming practice on the genetic variability of native species. In the present study, we measured the genetic structure of three model species —Microtus arvalis, Arion lusitanicus and Lumbricus terrestris— in an agricultural landscape with a diversity of land use types and farming practices. The aim of the study was to investigate whether different management strategies such as the method of land use or type of farming practice (conventional and ecological farming) have an impact on the species’ genetic structure. We used RAPD markers and multilocus DNA fingerprints as genetic tools. Genetic similarity was based on the presence or absence of bands, which revealed a wide range of variability within and between the analysed populations for each model species. Cluster analysis and Mantel tests (isolation by distance) showed different genetic structures in the populations of M. arvalis from sampling sites with different land use. However, the main factors influencing the genetic variability of these vole populations were geographic distances and isolation barriers. The genetic variability observed in A. lusitanicus populations correlated with geographic distance and the type of land use method, but no correlation was found with different farming practices. Our preliminary results suggest that the genetic structure of L. terrestris populations is influenced by the agricultural land use method used at the different sampling sites but not by the geographic distance