Natural and anthropogenic dynamics of the coastal environment in northwestern Corsica during the Holocene: new insights from Crovani pond.

Pollen, microcharcoal, sedimentary and geochemical analyses were carried out on a core recovered from the Crovani coastal wetland to reconstruct the regional drivers of landscape change. Crovani is a small backshore basin subjected to summer desiccation and without connection to the sea. The first evidence of human occupation of the area dates to the final interval of the Neolithic, but due to the presence of acidic soils the conservation of both the organic remains and archaeological material in its stratigraphic context was poor. From the Bronze Age to the Roman period, little archaeological evidence is recognized, and a significant resumption of human activities occurred only during the last millennium, related to the extraction of silver-bearing galena. The multidisciplinary approach allowed us to define the action of climate, geomorphological processes, and land-use on the landscape changes over the last 6,000 years. Our results highlight that anthropogenic and climate-induced fires favoured the development of Mediterranean maquis, dominated by Erica and Quercus ilex, from ca 6,000 to 3,350 cal. BP. A change in arboreal vegetation triggered a short but intense sediment input into the pond between ca 3,350 and 3,200 cal. BP. This is chronologically consistent with runoff events recorded in several coastal sites of western Corsica, possibly related to climate change that occurred in various sites of the western Mediterranean. The evidence of agriculture in our record is earlier than any archaeological evidence previously available in this part of Corsica and dates from 3,900 cal. BC. Human impact has been responsible for a degradation of the maquis only from approximately 1,000 cal. BC, and it intensified during Roman times, when the area experienced the first phase of galena exploitation. Our findings suggest that a combination of solar activity and the North Atlantic Oscillation had an influence on centennial-scale forest cover variations.