Il segnale climatico e le sue variazioni negli anelli di accrescimento degli alberi da siti estremi al contorno della regione mediterranea

Climatic signal and its variations in the tree rings from extreme environments bordering the Mediterranean region. Tree rings from climatically extreme environments, such as the Alpine treeline the arid and desert environments, allow the annually-resolved reconstruction of the climatic parameters most limiting tree growth in these areas. Climate proxies from the regions bordering the Mediterranean basin could provide a valuable contribution to palaeoclimate reconstructions in the area. Recent tree-ring chronologies of alpine conifers from the Italian Central Alps and discontinuous upper-mid Holocene chronologies of Cupressus dupreziana from the Libyan Sahara, confirm the possibility of obtaining meaningful palaeoclimatic information and quantitative reconstructions of the diverse climate parameters from annual tree rings. The Alpine tree-ring chronologies contain a summer-temperature signal, while the Libyan chronologies highlight the fluctuations of water availability in the Central Sahara over time. The information contained in these records can therefore contribute to a better definition of the past Mediterranean climate, showing how, by using dendrochronological data from sites limited by temperatures and by precipitations, relevant climatic information can also be derived from the bordering regions.