Natural and anthropogenic dynamics of the coastal environment in northwestern Corsica (western Mediterranean) over the past six millennia

Abstract

The present paper provides new insights into the climatic and anthropic factors that influenced a 6000year coastal evolution in northwestern Corsica, the third largest island of the western Mediterranean. Pollen, microcharcoal, sedimentary and geochemical analyses were carried out on a core drilled in the Crovani coastal wetland to reconstruct the regional drivers of landscape change. We show that anthropogenic and climate-induced fires favoured the development of Mediterranean maquis, dominated by Erica and Quercus ilex, from ca. 6000 to 3350 cal. BP. A change in arboreal vegetation triggered a short but intense sediment input in the Crovani pond between ca. 3350 and 3200 cal. BP. This is consistent with a coeval process of runoff recorded in several coastal sites of western Corsica and related to an arid climate change occurred in many sites of the western Mediterranean around 3200 years ago. We provide evidence of agriculture during the Late Neolithic from ca. 3900 BC, which is much earlier than any archaeological evidence previously available in this area of Corsica, followed by a progressive decline of arable farming practices. Human impact has been responsible for a degradation of the maquis only from approximately 3000 cal. BP, and it intensified in Roman times, when the area experienced the first phase of galena exploitation from the Argentella mines. Over the last 500 years, the present work evidences a major development of Castanea related to cultivation during the Genoese administration of Corsica. Our findings suggest that solar activity and the North Atlantic Oscillation had an influence on centennial-scale forest cover variations during the last 6000 years.

Mid- to Late-Holocene coastal morphological evolution, vegetation history and land-use changes of the Porto Gulf UNESCO World Heritage site and its surroundings (NW Corsica Island, Western Mediterranean)

“…BP/500 BCE-1800 CE) -Mixed forests of Pinus and Quercus ilex, accompanied by maquis of Erica were the predominant component of the landscape until the change of era, when forest decline led to the expansion of maquis, predominated by Erica and with an increasing role of Cistaceae (Figures 8 and 9). Until Roman times, human impact was limited in the evolution of forest cover in terms of short-term deforestation episodes and rapid recovery, consistent with previous studies in the area (Di Rita et al, 2022a). Only at Girolata can we report two brief episodes of forest decline dated ca.…”

“…As there are no known Early Bronze Age sites in this area of Corsica, an anthropogenic origin for this sudden change in vegetation cover is therefore highly hypothetical. As for the 4.2 kyr BP event, this climate change does not appear to be associated to any general deforestation patterns in Corsica (Di Rita et al, 2022a, 2022b. We can therefore only speculate that an arid climate event, if one occurred, had only a limited impact on intermittent coastal ecosystems.…”

“…Mid-to Late-Holocene coastal morphological evolution, vegetation history and land-use changes of the Porto Gulf UNESCO World Heritage site and its surroundings (NW Corsica Island, Western Mediterranean) 8720 km²), has been studied in an attempt to reconstruct humanenvironment interplays with robust chronostratigraphies on the coastal zone (Currás et al, 2017;Di Rita et al, 2022a;Ghilardi et al, 2017a;Revelles et al, 2019;Vella et al, 2019). All these studies are based on pollen analyses and have focused on humanenvironment interactions since Neolithic times (Currás et al, 2017;Di Rita et al, 2022a;Ghilardi et al, 2017a;Poher et al, 2017;Revelles et al, 2019;Vella et al, 2019).…”

“…Mid-to Late-Holocene coastal morphological evolution, vegetation history and land-use changes of the Porto Gulf UNESCO World Heritage site and its surroundings (NW Corsica Island, Western Mediterranean) 8720 km²), has been studied in an attempt to reconstruct humanenvironment interplays with robust chronostratigraphies on the coastal zone (Currás et al, 2017;Di Rita et al, 2022a;Ghilardi et al, 2017a;Revelles et al, 2019;Vella et al, 2019). All these studies are based on pollen analyses and have focused on humanenvironment interactions since Neolithic times (Currás et al, 2017;Di Rita et al, 2022a;Ghilardi et al, 2017a;Poher et al, 2017;Revelles et al, 2019;Vella et al, 2019). Some of these studies have also revealed that most of the coastal plains formed during the Late-Holocene due to a general mechanism of deltaic progradation of the river mouths (Currás et al, 2017;Ghilardi et al, 2017a), following a period of maximum sea incursion that can be dated slightly before the Mid-Holocene (Revelles et al, 2019;Vacchi et al, 2016Vacchi et al, , 2018.…”

Small Mediterranean coastal Lagoons Under Threat: Hydro-ecological Disturbances and Local Anthropogenic Pressures (Size Matters)

“…An excellent example with regard to this major challenging goal of the conservation of coastal lagoons, especially in the Mediterranean region, is Corsica Island (France), located in the north-western Mediterranean Sea. The island has more than 200 coastal wetlands, mostly brackish coastal lagoons, highly diverse and is a good example for the study of small-sized coastal lagoon environments (Ghilardi 2021;Di Rita et al 2022). Only the four largest lagoons are well known, since they fit with the WFD criteria and have been the subject of numerous scientific studies and monitoring surveys.…”