[1] Univ Clermont Ferrand, CNRS, UMR 6042, GEOLAB, F-63057 Clermont Ferrand, France
[2] Univ Angers, Dept Geog, CNRS, UMR 6042 Geodynam Milieux Nat & Anthropises, F-49000 Angers, France
[3] CNRS, UMR 5172, Lab Dynam Biodivers, F-31055 Toulouse, France
[4] Univ Lyon 3, CNRS, UMR 5600, Environm Ville Soc, F-69362 Lyon, France