Authors: Boyer, Igor; Pagano, Alain;Bertrand, Romain;Isselin-Nondedeu, Francis;

Ectotherms should move poleward in response to the changes in temperature and precipitation regimes induced by climate change. Consequently, species may reach new habitats in their northern range-margin that become newly suitable. The ability of a species to track isotherms depends both on its dispersal abilities and on the landscape permeability. However, the current landscape is highly fragmented by anthropogenic habitats such as crops and urban areas that impede or limit movement of individuals. In this context, we seek to determine whether the current landscape allow species to track climate changes in their range-margins? We run habitat suitability models and landscape graphs that simulate ecological corridors for Hierophis viridiflavus, Lacerta bilineata, Natrix maura and Triturus marmoratus in their north range margins. With the notable exception of L. bilineata, all species are decreasing. Outputs of the models allow to locate explicitly areas lacking corridors therefore prone to limit species range-shifts. For all species, highly cultivated areas are associated with low density of corridors. Finally reachable areas for species inhabiting wetlands are restricted. The restoration of wetlands throughout anthropized landscape is therefore primordial because they could act as steppingstones.