Characterization and perception of climate change at viticultural terroir scale

Abstract

Great variations in climatic conditions exist within wine growing areas, as a result of geomorphology, land cover, proximity of main water bodies and urban areas. This means that climate change (CC) will not have the same impact on various locations within a wine growing area. Hence, CC must be studied at a very fine scale. Until now, very little research has been dedicated to the issue of the effects of CC at local scales. Our study aims to acquire a better understanding of climate on grapevine behavior at viticultural terroir scales in order to study more accurately adaptation to CC. Various objectives are targeted: i) acquisition of meteorological and agronomical measurements at fine scales, ii) downscaling of spatial climate modelling, iii) taking into account the current knowledge, practices and issues about CC as expressed by growers and producers in the wine industry. Several study sites were established and instrumented in France, especially in the Loire Valley and at Saint-Emilion. The results show a strong spatial variability of temperature and phenology, mainly due to local effects. Downscaled climate models then allowed climate modeling at local scales as well as regionalized simulations (temperature and phenology). Moreover, the perception of CC by growers and producers and sensitivity of viticultural practices to climatic hazards were studied from field surveys. In parallel, similar studies are conducted in South America in climatic conditions that could correspond to future scenarios for French vineyards: Mendoza, Argentina where a semi-desert warm climate prevails and southern Uruguay in temperate warm oceanic conditions. These results are used to develop adaptations strategies at different spatial and temporal scales for growers and producers.