A high-resolution record of landscape changes and land use over the last 5000 years in western Calabria (S. Eufemia Gulf, southern Tyrrhenian Sea, Italy)

Abstract

Pollen analysis of a marine core collected in the Gulf of S. Eufemia (Tyrrhenian Calabria, Italy) allowed reconstructing the regional changes in vegetation and land use over the last 5000 years. Pollen diagram zonation through Constrained Cluster Analysis highlighted three compositional zones whose boundaries mark the major changes that affected the vegetation structure. A dense forest cover with a few signs of human activities characterized the wide pollen source area from 5055 to 2700 BP (Zone 1). In this period, the Pre-Protohistoric communities were mainly concentrated on the Tropea Promontory where they had a significant local impact. Minor forest rarefactions at 5000–4800 BP, ca. 4400–4000 BP, ca. 3450–3150 BP were correlated to phases of climatic shifts toward aridity. From 2700 to 2000 BP (Zone 2a), a longer and more incisive period of forest decline was connected to a time of aridity that favored the intense activities of an increasing anthropogenic pressure. Indeed, important urban centers developed in the area during the Greek and Roman colonization. Diffuse deforestation and cultivation occurred from 790 BP (Zone 3), enhancing soil erosion and fluvial discharge as testified by the sudden increase in sedimentation rates. This disruption of the slope morphodynamics was connected to the collapse of territorial management following the end of the Western Roman Empire. Compositional Data Analysis, applied to a simplified pollen dataset, highlighted both a negative correlation between Abies and Fagus and a close similarity between the AP/NAP curve and the Axis 1 scores of the Relative Variation Biplot.