Climate changes' effects on vegetation water stress in Mediterranena areas

Many recent studies have demonstrated that CO(2) increase is driving the climate in Mediterranean areas towards important changes, mainly represented by a temperature increase and a contemporaneous rainfall reduction. Starting from this premise, the primary aim of the present study is to investigate the effects of potential climatic changes on vegetational stress in Mediterranean ecosystems. Particular attention is here focussed only on the plants' water stress in water controlled ecosystems, mainly related to soil water balance. The interactions among climate, soil and vegetation are evaluated numerically by means of an ecohydrological model. In this work, different future climatic scenarios and their effects on woody and grassy vegetation are analysed, and the results show an increase in water stress for woody and grass vegetations: trees could suffer more because of the higher evapotranspiration rates and the decrease of the winter recharge. Results are strictly dependent on the future rainfall seasonal distribution and the possible modification in rainfall frequency and intensity.