The Roussy peat-bog is located in the western part of the Massif du Cantal a part of the Massif central that had never been explored before. The pollen analysis reveals a dynamic of the vegetation starting from the Allerod and globally in harmony with the palaeobotanical context reconstructed by previous research (Beaulieu et al , 1988). However several particularities can be observed : a regional presence of the elm since the Preboreal, a progressive expansion of the hazel until its maximum in the Boreal, a very weak development of the fir This multi-disciplinary study (archaeology and history) allowed the modelling of the evolution of agro-pastoral activities in this area. A first human impact can be reported for the end of the Bronze Age or the Hallstatt. Anthropization at Roussy shows a late preservation of the beech forest despite an agro-pastoral presence clearly attested It is only after the 1st millenium AD that an important agricultural influence is observed together with an irreversible retreat of the forest. The successive penods show an important but discontinuous anthropic pressure. In parallel, a search for new geochemical markers (Mg, K, Ca, P) of the anthropisation has been undertaken.