Type regions F-zg and F-r, the northen slope of the Pyrenees
From the Atlantic Ocean to the Mediterranean Sea, the Pyrenees form the westernmost mountain chain of E-W orientation in the south of western Europe. We can distinguish two regions : an Atlantic zone and a Pyrenean zone. The Pyrenean chain shows in each of these zones a great diversity of local climatic characteristics. This paper attempts to illustrate the methodological approach we need to reach a palaeoecological synthesis. Five or six studied sites in different vegetation belts of the Chaîne des Hurtières are presented.