All shades of green
The crystalline Périgord is one of the margins of the Massif Central. Its marked relief with points between 300 and 400 metres in altitude is associated with slightly more rainfall than the rest of the department. Its flora is characterised by numerous acidic species, with mountain affinities, which in many ways remind us of those predominant in the neighbouring Limousin. Indeed, this Green Périgord is made up of high plateaus, as in Limousin, as many foothills of the nearby Massif Central. It extends from the north to the north-east of the department and is based on primary formations. The general aspect of this region is made of plateaus with slowly undulating ridges, but also narrow, even steep valleys. Let us quote in particular the gorges of Auvézère, river sometimes calm, sometimes capricious, it offers very contrasted faces. You can discover it quietly during a fishing trip and the next day, unleashed. It depends on the seasons and the place where you are. The Auvézère river has its source in the Massif Central, enters the Dordogne and flows into the Isle. It is precisely in the Green Perigord that it is most closely discovered: in Payzac, Savignac-Lédrier, St-Mesmin or Génis. It has shaped unique mountain landscapes in the Dordogne. However, it remains rather unknown, wild, powerful and capable of devastating floods. It has also allowed the industrial development of its basin, with many dams and forges. Finally, this green Périgord is marked by the presence of woods and meadows that give it a bocage appearance. It is the land of choice for the extensive breeding of Limousin cattle.
Dominantly limestone soils
The centre of the Périgord is a vast area of Cretaceous limestone, with large areas of siderolithic veneers (acidic sandy areas). The natural erosion by the rivers has formed a landscape with modest hills (150 to 230 metres) interspersed with valleys. It is the kingdom of pedunculate oaks and chestnut trees. This territory presents quite diversified grounds which allows a polyculture where the strawberry plays however, for several years, a very important role. The terroir of the Ribéracois is very similar, punctuated, however, by small causses (Mareuil and Paussac). It is a low-lying plateau, a land of choice for cereals but also for cattle breeding thanks to the meadows in its small valleys. There has been a recent development of fatty poultry production in this area. The Sarladais, on the other hand, is made up of a vast cretaceous limestone plateau 250 to 350 m high. The very powerful erosion of the Dordogne and Vézère rivers has created a landscape with a high degree of topographical variability: cliffs, meanders (cingles), hills, valleys and valleys give rise to a wide range of microclimates and, consequently, a variety of species. Some sectors have almost Mediterranean affinities. The valleys are cooler and shaded. This mosaic of environmental conditions has consequences on the use made by men of these different lands: corn at the bottom of the valleys, walnut and chestnut trees on the plateaus and presence of truffle oaks. The causses, on the other hand, correspond to areas of compact Jurassic limestone, an extension of those of the Quercy. It is an alternation of plateaus, arid hills and rare waterways. The Périgourdins causses are usually divided into four sub-areas: causses of Cubjac-Thenon, the hillsides of Terrassonnais, that of Terrasson-Nadaillac and that of Daglan. Finally, the Bergeracois, along the lower valley of the Dordogne, is to be distinguished from the other limestone terroirs of the department. It is composed of a substratum formed of tertiary detrital deposits, predominantly limestone. It is a vast plateau with a touch of limestone and mollassic formations of the Terrefort du Dropt, limited in large part to the north by the Dordogne valley. It is a land of choice for vineyards, with large areas of land devoted to cereals in its southern part
The largest towns in the department are located in this Périgord on a limestone base. It has favoured human settlement, the urban development of buildings and infrastructures, thanks to the use of stone as the main building material. This limestone Périgord, with a relatively accessible relief and wide valleys, benefits from a large number of transport routes, unlike the north of the department, which is still rather isolated. The limestone bedrock has also allowed the development of a lime industry (Saint-Astier).
The exceptions of the Double and the Landais
Located in the west of the department, on either side of the Isle valley, these two sectors are characterized by a moderate relief, covered with an acid clay-sand substratum. This is the spontaneous sector of the Tauzin oak, to which men have added numerous plantations of maritime pine. The flora therefore takes on accents of the Atlantic zone, recalling for example that of the Landes de Gascogne. There is a very important hydrographic network in the Double, which has allowed the development of a flora specific to wetlands. The Double is an exceptional terroir, which lies on the sands and clays of the Périgord. It is a vast wooded plateau, with an impermeable subsoil, dotted with ponds. Fish farming, forestry and animal husbandry are the dominant productions. For a long time, it was a landlocked country; the Doublaud people suffered from malaria and great insecurity; wolves in their natural state were present there until 1914 in its deep forest. It is also a land of legends and superstitions. The Landais is the extension of the Double to the south of the Isle valley, this region presents hills with slopes covered with vines which announce the vineyard of the south of Bergerac. In conclusion, you will notice that the Périgord is not a territory with clearly marked borders. Its division is rather the work of political and administrative wills, so that one can notice a strong porosity of the landscapes of the bordering departments.
