A new interpretation of bioclimatic indices at local scale in Italy

Abstract

Viticulture is strictly related with weather and climate. Italy is a world leader in the wine business but also a known hot-spot for climate change. In the last decades, Italian winegrowers already experiences the effect of climate change, especially in terms of warmer growing season, more frequent and longer drought periods, increased frequency of weather extremes as well as shifts in phenological phases, that increase the exposure of the plant at frost risk. This study investigates the impact of climate variability and change on grape yield at local scale in three wine consortiums. Using climate variables from the E-OBS observational dataset, we computed a range of bioclimatic indices, selected by the International Organisation of Vine and Wine (OIV), and correlated them to grape yield data from three wine consortiums in in northern and central Italy. The collaboration with consortiums allows to include in the analysis other factors, besides climate, that influences wine productivity like vineyard management, policies and market.We evaluate how the interannual variability and the changes in the bioclimatic indices impact on grape productivity in the study areas using a single regression approach. We also combined the bioclimatic indices into a multi-regression analysis to investigate if a more complex methodologyincreases the portion of total yield variability explained, in comparison with the single regression approach. Keyword: climate change, agroclimatic service, wine, local scale