The influence of recent climate variability on viticultural zoning and variety regionalization of <i>Vitis vinifera</i> in China

The objective of this work was to estimate the influence of climate variability on viticultural zoning and variety regionalisation in China in the past 50 years. A multicriteria climatic indices system, which includes Frost-Free Season (FFS), Dryness Index (DI), and Extreme Low Temperature (ELT), was used to define climatic suitable areas and classify different climate zones for wine grape-growing in China. The Accumulated Effective Temperature (AET) was used as an index of variety regionalisation. Indices were calculated based on daily climatic observations from national ground weather stations throughout China from between 1967 and 2016. The variation trends were analysed by Sen’s slope and Mann-Kendall non-parametric tests in 13 representative wine growing sites. Based on the studied criteria, the suitable viticultural zone exhibited a continuous northward expansion with an average increase of 0.204 million km2/decade, largely due to increasing FFS. A significant increase of FFS was detected in most representative sites, with almost no detectable change of DI during the growing season. The analysis also revealed that the North East Region, Inner Mongolia Region, and Xinjiang Region are the three most profitable wine regions. Movement of the soil-burying line was limited to Shandong and Hebei provinces. Although the suitable viticultural zone increased, the data also revealed a decrease in the area for high quality wine production when considering varietal suitability. These results have important implications for understanding both new opportunities and challenges under changing climate and the latter’s effects on viticultural viability in China. They can also help guide stakeholders to develop adaptive strategies for maintaining the profitability of currently used regions and for developing new regions for viticulture.