Agroclimatic characterisation of European mountain viticultural areas

The adaptability of Vitis vinifera L. to a wide range of climate and soil types is the result of the genetic plasticity associated with the variety of management practices and training systems that represent the result of a long historical evolution . In this context climatic variables (solar radiation, temperature, relative humidity, wind, precipitation and so on) play a primary role as driving variables for plants and show strong effects on quantity and quality of viticultural production. In the light of this, agroclimatic analysis is an important instrument for zoning viticultural aptitude at different scales, from macro to microscale. In this paper a specific application of this analysis to the European mountain areas that are part of the CERVIM (European Centre for Mountain Viticulture) is discussed. First classification element adopted was the effect of synoptic circulation that represents the carrier of different kinds of air masses (arctic, polar maritime, polar continental, subtropical) that directly influence European climate giving tree different macroclimates: an Oceanic climate typical of Central Europe, a Mediterranean one typical of lands surrounding the Mediterranean basin and a transitional climate typical of North Italy. A meso and microscale characterisation of selected areas was obtained by means of indexes related to vine physiology (Thermal units, Huglin index, potential PAR, precipitation regime, continentality level, etc.) and water balance (e.g.: number of days with empty reservoir). These indexes, obtained from the processing of climatic normals, were defined for the lowest and the upper limit of each viticultural area, obtaining a quantitative description of the spread of these indexes along the selected territories. The general conclusion of this analysis is that resources and limitations in climate are key factors for agro-climatic zoning; the effects of these factors on phenological and physiological features must be studied and quantitatively evaluated. Another conclusion is that a general rule does not exist and key factors are quite different in different areas giving local effects that represent the element of originality and uniqueness of wine produced in mountain areas.