Climate influences on grapevine phenology, grape composition, and wine production and quality for Bordeaux, France

摘要

Grapevines are grown in distinct climate regimes worldwide that provide ideal situations to produce high quality grapes (de Blij, 1983). One region where this is evident is in Bordeaux, France, a grape growing area that is synonymous with some of the best wines in the world. While the interactions between the local climate, soil, and site location (termed the "terroir" by the French) play a varied role in the ontogeny and yield of the grapevines, the general effect of climate is known. Mild to cool and wet winters followed by warm springs, then warm to hot summers with little precipitation provide adequate growth potential and increase the likelihood of higher wine quality (Coombe, 1987 and others). Therefore, there is an optimum seasonal climate regime that contributes greatly to the overall quality of a given vintage (for a good review, see Gladstones, 1992). Occurring as a direct effect of climate, the grapevine's growth can be described by its phenological events. Vitis vinifera grapevines are a phenologically distinct crop with the most important developmental stages being debourrement (budburst), floraison (flowering), veraison (color change and maturation nascent), and harvest (grape maturity). The timing of these developmental stages is also related to the ability of the vine to yield fruit, with early and fully expressed phenological events (i.e., adverse weather during floraison would disrupt the event) usually resulting in larger yields (Mullins et al., 1992; Jones, 1997). Additionally, phenological timing has been related to vintage quality with early harvests generally resulting in higher quality vintages (Jones, 1997). The goal of this research was to develop a long-term daily phenological-interval climatology to study climate's effect on grapevines. Unique to this study was a division of the year into "physiologically correct seasons" as dictated by the plants (i.e., a variable interval determined by plant physiology rather than some arbitrarily fixed set of intervals determined by calendar dates). The method provided a more comprehensive examination of when, during the growth intervals, climate elements have the greatest impact on grape growth and production. Overall, the research provides for mid-season, yearly, and long-term assessments of climate/viticulture relationships in the Bordeaux region.