Cambios en el paisaje del Valle de Ordino al inicio del holoceno: evolución geomorfológica, paleovegetal e incendios de época mesolítica

(ENG) Mesolithic palaeoenvironment in the Ordino Valley -NW Andorra, Southeastern Pyrenees: Landscape changes in the Early Holocene Flooding sediments at Sornàs (1300 m asl) provide new information about geomorphological changes since the Last Termination and the Holocene in a high Mediterranean valley. The sedimentary record had several charcoal layers dated from 9625 to 5560 cal BP (Mesolithic and early Neolithic). Charcoal analyses between 9625 to 9155 cal BP has been carried out depicting that the valley was mainly occupied by Pinus sylvestris woodlands; but also that these forests were affected by burnings frequency of 60 -180 years. Pollen analyses elucidate the presence of apophyte taxa just after the charcoal layers. The proximity of the archaeological site of Balma Margineda (960 m asl) recording a human occupation from the Epipaleolithic to the Early Neolithic times, allows us to discuss about a woodland management by Mesolithic groups.