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Abstract

Regional climate scenarios for German viticultural areas for the time periods 1951-2000 (basis scenario derived from observation data) and 2001-2050 (future scenario) compiled for the A1B emissions scenario were developed using the regional statistic climate model STAR. Climatic developments were analysed for 11 meteorological variables and for special days.
Possible changes in the German viticulture were investigated using a thermal index (HUGLIN). A general tendency indicated a northbound shift of viticultural areas as well as an ascent to higher elevations.
Model-supported investigations of grapevine phenology were done by coupling the climate scenarios with a model for the phenology (for cv. Riesling). Model runs were used to evaluate changes in the three investigation areas. As a general tendency an acceleration of all phenological phases was noted.
Evaluation of climatic variables relevant to viticulture was performed for the individual phenological phases. The results indicated critical changes including, e.g., an increasing probability of the occurrence of tropical nights (Tmin ≥ 20°C) which would potentially endanger the character of the Riesling, and an increased probability of humid conditions during maturation, with the danger of higher pest load.
For the development of adjustment strategies, dialogue with experts from practice and research was suggested as means to identify possible measures and to evaluate remaining chances and risks, with a focus on individual cases.
An extension of the investigations to further viticulture regions is planned, paying special attention to changes in the complex system climate grapevine pests. The results of expert-led stakeholder dialogue will induce the development of adjustment strategies for specific viticulture regions.