Future Scenarios for Viticultural Climatic Zoning in Iberia

摘要

Weather and climate are among the environmental factors that most influence grape yield and wine quality. Since predicted climate change and its likely impacts are under discussion, the assessment of possible implications on wine production, including changes in bioclimatic indices and viticultural zoning is plainly justified, setting the basis for defining adaptation/mitigation strategies. In this context, the main objectives of present study are the determination of four bioclimatic indices (length of the growing season, Huglin index, cool night index and dryness index) for Iberian winegrowing regions, the assessment of their variations under an emission scenario by using a state-of-the-art climate model, and the definition of regions with diverse viticultural potentials. For their calculation, mostly precipitation, maximum and minimum air temperatures on a daily basis are used. Then in order to identify spatial changes in their patterns, the indices are calculated for the periods 2041-2070 and 2071-2100 using data from the climate model COSMO-CLM (regional atmospheric model) and for the A1B SRES emission scenario. Data from COSMO-CLM has a high-resolution grid (0.165° latitude × 0.165° longitude) allowing a detailed characterization of viticultural regions and the assessment of the impacts of different climatic scenarios on Iberia. Maps of these indices for recent-past periods and for future scenarios are considered. Furthermore, a validation methodology highlighted the high skill of this regional model in reproducing the recent-past climate patterns in both precipitation and temperature fields throughout the Iberian Peninsula. According to the model simulations, there is a projected significant adverse impact on wine quality, namely in Southern Iberia, by increased dryness and cumulative thermal effects. This scenario represents an important constraint to grapevine growth and development, making it crucial that adaptation strategies be adopted. This approach provides a macro-characterization of Iberian areas where grapevines may preferentially grow, as well as their projected changes under human-induced forcing. As such, it can be a useful tool for viticultural zoning in a changing climate.