Abstract
The archaeological site of Rajal del Gorp is located in asinkhole in the Causse du Larzac (785 m alt.). The cave was inhabited from the Mesolithic (earliest occupation dated to the VII-VI Millennia B.C.) up to the late Antiquity (IVth century A.D.). Charcoal analysis concerns a succession of 16 layers, constituting the most comprehensive sequence in this region. The vegetation dynamics outlined is clearly related with the post-glacial warming: dominance of Pinus type sylvestris in the early phase while deciduous oak expands at least from the Middle Mesolithic / Early Neolithic onwards. This transition occurs at the same time as that reviously described in the Larzac, but is late when compared with the Causse Noir and other southern sites, at lower altitude. Pine forests are gradually transformed into mixed oak forests, where deciduous oaks and pines grow in sporadic association with other species. By the end of Early Neolithic, oaks become dominant, while pines – which are currently absent – remain present until the site is abandoned. The low frequencies of beech, identified as early as in the Middle / Late Neolithic and up to the Roman period, testify to the early presence of this species in the midst of mature oak forests. These forests which were gradually transformed into dense coppices, sheltered beech, which remained poorly adapted to the local climate. Scarce heliophilous taxa, associated with forest clearance or favoured by pastoral activities, appeared during the Middle / Late Neolithic period and persisted until the end of the sequence, but always with low frequencies. This is consistent with moderate anthropogenic impact. Nowadays, the only woody species still growing in the vicinity of the site are Buxus sempervirens and Juniperus communis which escaped grazing. This study proposes a palaeoenvironnemental synthesis and provides new data concerning the evolution of the Holocene woody vegetation in the Causse du Larzac. Those on the Iron Age are the first ever obtained in the region.