Humans, Forests and Climate Change in the Central Mediterranean

Abstract

The present-day Mediterranean vegetation landscape is the result of a long “coevolution” between climate, vegetation, fauna and human activities. During the Quaternary, glacial-interglacial oscillations, driven by orbital variations in eccentricity, obliquity and precession and amplified by climatic feedbacks, caused repeated contractions and expansions of forests. Despite the persistence of tree taxa in refugial areas, these dynamics led to a progressive loss of forest diversity. The Mediterranean region, and particularly the Italian Peninsula and the Balkans, played an important role as both a refugium and a corridor for recolonization, within an area nevertheless highly vulnerable to aridity and climatic seasonality. During the Holocene, forest recolonization was rapid but spatially differentiated. In central Italy, deciduous oak woods, beech forests and alder woods expanded, whereas in central Sicily an early postglacial humid forest phase, characterized by deciduous and evergreen oak woods, was followed by progressive aridification from as early as 8000 years ago. Across the region, from the middle to late Holocene onwards, human impact became increasingly significant: fire, grazing, agriculture, timber exploitation and tree cultivation, including olive growing, profoundly transformed the structure and composition of landscapes. Nevertheless, remnants of old-growth woodland and ancient trees still represent a distinctive feature of Mediterranean landscapes today, both in cultural landscapes and in more remote areas where old-growth characteristics are more strongly preserved. For contemporary forest management, palaeoecological data show that there is no single natural reference condition, or natural baseline, to be restored. Mediterranean forests are often cultural ecosystems, whose history continues to shape their dynamics even in the absence of direct human activities. Their management must therefore consider ecological memory, resilience thresholds, natural and anthropogenic disturbances, soil fertility, water availability and future climate scenarios.