Viticulture suitability estimates under climate change in Japan

Abstract The wine industry has been gathering considerable attention from many perspectives in Japan, one of the New World producers. This study aimed to provide novel viticulture suitability estimates under current and future climate conditions in Japan. The multivariate viticulture suitability estimation model using MaxEnt showed good performance in predicting regional viticulture suitability. We found that the variability in accumulated precipitation and time-averaged vapor pressure deficit during the growing season largely determine the viticulture suitability in Japan under current climate conditions, which is unique to the region with relatively humid climate. New viticulture suitable regions under current climate were revealed in northern Japan regions (e.g., Aizu and Naka-dori areas in Fukushima prefecture and some local areas in Hokkaido). Estimated future changes in viticulture suitability showed that while the current active viticulture regions, including Kofu Basin, will experience significant decline with timeframe, wide area of Hokkaido will experience notable increase in viticulture suitability. A significant increase in suitability is observed across wide areas of Hokkaido and northern part of main island under RCP 8.5 scenario for 2100s. Overall, climate change will lead to a geographical shift in Japanese viticulture regions, generally moving towards more northern and higher-altitude areas, with complex local variations. We further examined how viticulture suitability changes will respond to the changes in vine phenology with the perspective of potential local adaptations. As a result, the degree of decrease in suitability at Kofu Basin was found to be mitigated by shifting the growing season forward. Findings of this study will be a basis for future viticulture planning and management in the region.