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Climate change modifies the base climate of the wine regions and, with it, the structure of their traditional types of wine production, imposing measures to adapt, mitigate, or capitalize on the newly emerging conditions. In order to assess the impact of climate change and establish the appropriate adaptation measures for each wine region, regional and local studies are needed, which allow knowledge of their current climate profile. The aim of this research was to identify the changes that appeared as an effect of climate change in the initial climate profile and the initial structure of the traditional types of wine production of Bordeaux (France), Loire Valley (France), Rhine-Main-Nahe (Germany), La Rioja (Spain) and Cotnari (Romania) wine regions, and also in climate suitability for wine production of the Sussex area from the UK. The study uses multi-year averages for the 1951–1990 and 1991–2010 time periods of reference bioclimatic indices for viticulture, namely the Average Temperature of the Growing Season (AvGST), the Huglin Index (HI), and the Oenoclimatic Aptitude Index (IAOe). The results of this research reveal significant changes in climate suitability for wine production of the studied wine regions: in the Bordeaux wine region, climate change led to the appearance of conditions for the cultivation of the Mediterranean climate varieties Grenache, Syrah, and Carignan; in the cool climate wine regions Rhine-Main-Nahe and Cotnari, traditional producers of white wines, the climate has also become suitable for the cultivation of Pinot noir and Cabernet franc varieties, and implicitly for the production of red wines; in all studied wine regions, the classes of climate suitability for viticulture shifted higher in altitude, as is the case of the La Rioja region, where, in the recent period, the grapevine can be grown up to 922.9 m asl, higher by 206.2 m compared to the 1951–1990 time period; in the low area of each wine region, one or even two new climate suitability classes for wine grape growing appeared. The shifts revealed by this research generate solid conclusions regarding the effect of climatic change on the viticultural potential of geographical areas, namely: in the context of climate change, the altitude of the wine region has a major influence on the evolution of the local viticulture potential; a higher topography allows a better adaptation of the wine region to climate change; low-elevation wine regions are more vulnerable to climate changes, especially the further south they are located; as an effect of climate change, conditions appear in the wine regions for the cultivation of new grapevine varieties and the production of new types of wine. [ABSTRACT FROM AUTHOR]

Warming trends over the winegrowing regions lead to an advance of grapevine phenology, decreased yield and increased sugar content with a lower polyphenol content. We hypothesized that different leaf removal timings may counteract these effects. A two-year experiment was conducted in La Rioja (Spain) with Vitis vinifera L. cv. Grenache trained in an open-vase system. Trial consisted in a complete block design with two leaf removal treatments differing in the moment of manipulation: i) severe leaf removal treatment conducted after fruit set (ELR); and ii) severe leaf removal at veraison (LLR) compared to an untreated control (Control). Both leaf removal treatments tended to decrease sugar content with no effect on yield, these effects being highly affected by the year. Defoliation accounted for a decreased flavanol and stilbene contents in berries at harvest. An ELR increased anthocyanin and phenolic acid contents at harvest, while warming during 2022 accounted for decreased contents of all the monitored groups of flavonols. ELR was only effective for delaying ripening by means of impairing the sugar:anthocyanin decoupling during the 2021 growing season which was related to lower % of kaempferol. Altogether, results suggested that defoliation should still be applied under currently warming trends in some viticulture regions. • Defoliation effects on berry metabolism are dependent on growing season. • Early leaf removal showed a higher impact on berry metabolism than late leaf removal. • Early leaf removal reduced sugar:anthocyanin decoupling in the cooler season. • Kaempferol is a good biomarker of the coupling of primary and secondary metabolisms. [ABSTRACT FROM AUTHOR]

Highlights • The effect of trimming around 40–60% of shoot length was evaluated. • Vine water status was determined through stem water potential and carbon isotope ratio analyses. • Positive effects of trimming on vine water status were only observed with warmer and drier climate conditions. • Yield, cluster number and cluster weight were not affected by severe trimming. Abstract Viticulture in Southern Europe heads towards a scenario of drier and warmer the growing seasons due to climate change. This decrease in the amount of water available for the vines and increase in evapotranspiration make necessary finding strategies to reduce vineyard water needs. In this context, the effect of severe trimming (40–60% of shoot length), performed at pea-size stage, on plant water status was evaluated in four different vineyards located in North of Spain. Severe trimming improved plant water status clearly only when climate conditions were more demanding, whereas only a slight improvement or no change was observed elsewhere. Lower leaf areas resulted in less water deficit following a logarithmical trend revealing that the effect was more pronounced at low leaf area levels. Severe trimming had non-significant effects on cluster number, yield and cluster weight, but presents a tendency to reduce total soluble solids content and to increase total acidity, consequently delaying ripening. [ABSTRACT FROM AUTHOR]