DETERMINANTS OF ADAPTATION OF GRAPEVINE TO AN EVOLVING CLIMATE: HYDROLOGICAL CONDITIONS AND CULTIVARS BIODIVERSITY

Soil water availability is one of the main determinants of crop yield and of adaptation to a changingclimate. The aim of this study was to analyse the soil water regime, as determined by climaticconditions, in combination with the intra-specific biodiversity of yield responses of grapevine to wateravailability. The adaptability of wine-producing cultivars to future climate was thus assessed.In a region of southern Italy the effects of climate evolution on soil water availability weredetermined. Through a mechanistic model, simulations of the soil water regime were performed overthe study area accounting for spatial variability of soil hydrological properties. Two climate caseswere considered: reference (1961-1990) and future (2021-2050). Hydrological indicators werecalculated from model outputs. For several wine-producing cultivars, hydrological requirements weredetermined by means of yield response functions to water availability. Cultivar-specific hydrologicalrequirements were then evaluated against hydrological indicators of soil water availability to assessadaptability, i.e. the probability that a given cultivar attains the target yield under a specificcombination of climate and soil conditions. The potential spatial distribution of wine-producingcultivars was thus determined.The future climate was characterized by higher mean temperatures and by a decrease in precipitation.The variability of soil types affected cultivars adaptability. For instance, in the alluvial terraces andalluvial plain environments the soil water availability was higher and the hydrological indicators hadquite similar values in both climate cases; therefore, the adaptability of the cultivars did not vary fromthe reference to the future climate in a large part of these environments.