Impact of Global Warming on Environments for Apple and Satsuma Mandarin Production Estimated from Changes of the Annual Mean Temperature

This study was undertaken to assess the impact of global warming on the production in Japan of apple (Malus domestica Borkh.) and satsuma mandarin (Citrus unshiu Marc.). The annual mean temperature was used to simulate possible changes in favorable regions for the cultivation of apple and satsuma mandarin. The temperature ranges assumed to be appropriate for fruit production were 6-14°C and 7-13°C for apples and 15-18°C for satsuma mandarins, respectively. The database of "Climate Change Mesh Data (Japan)" was used to calculate annual mean temperatures under the climate change scenario, derived from four Atmosphere-Ocean General Circulation Models (AOGCM) at all 10 X 10 km mesh. It was predicted that the favorable regions to cultivate apples and satsuma mandarins will gradually move northward. In 2060's the plains of central Tohoku will be unfavorable for apple cultivation, while most of Hokkaido will be suitable. The plains of northern Tohoku are predicted to attain the annual mean temperatures higher than those of the current main producing districts. By 2060's, the favorable areas for satsuma mandarin production will possibly move from the southern coastal sites to inland areas of western and southern Japan, the plains of Kanto and the littoral zones of the Japan Sea in the central and western Japan and in southern Tohoku. Therefore, global warming will greatly affect the cultivation environment of apples and satsuma mandarins in Japan by the middle of the 21st century.