Abstract
The persistence of mesophilic taxa at low altitude until the year one thousand in Languedoc was established by comparing three kinds of sources : written documents, microtoponymy and charcoal analysis. They were localized everywhere around the whole mediterranean area of the Central massif. Mountain species or species from middle Europe were present : mainly beech, fir and hazel tree. They survive in privileged edaphic conditions along riversides or at the coastal pondsides. The great clearing of the XI century definitively eliminated these species. From 1040-1060, the increase of "Condamines" testifies that the heavy soils with alluvial deposits were integrated into the farming system. Therefore, the action of peasants during the XI century laid down the present level of vegetation.