Using fuzzy similarity priority ratio to analyse climate similarity between Fujian and Taiwan for fruit tree cultivation

The wide introduction of tropical and subtropical fruit trees from Taiwan to Fujian has brought significant economic benefit in recent years. But this blind approach still carried high risks in the farming communities in Fujian. A climate similarity study between Fujian and Taiwan was conducted for the introduced fruit trees to guide government and other stakeholders optimize distributions of the fruit trees. This study aimed to reduce or eliminate the risks associated with the blind introduction of fruit trees from Taiwan to Fujian and to improve the yield and quality of the cultivated fruits. The study used Gaoxiong City as a representative origination source region of major fruit cultivation area in Taiwan Province. Then a total of 67 counties in Fujian Province were used as the receiving source regions in mainland China. A total of seven climatic factors were compared in the study - annul mean temperature, mean minimum temperature in the coldest month (January), extreme minimum temperature of previous years, annual precipitation, annual sunshine hour, annual mean wind speed and annual mean relative humidity. Based on the meteorological data of Gaoxiong City for 1981-2010 and that of the 67 counties in Fujian Province for 1971-2011, the investigated climatic factors and climate similarity between Taiwan and Fujian for fruit tree cultivation were analyzed. While the fuzzy similarity priority ratio method was used in the analysis, the Analytical Hierarchy Process (AHP) was use to weigh the agricultural climate similarity indices. The agricultural climate similarity priority was classified into five degrees based on the total values of the fuzzy similarity priority ratios - higher, medium, relatively poor, poor, none similar. Spatial distribution maps of agricultural climate similarity of the fruit trees were then drawn in GIS or Surfer platforms. The results showed that: (1) Agricultural climate of most counties in Zhangzhou coastal area, Tong'an District in Xiamen City had high climate similarity with Gaoxiong City. Putian City, most of Quanzhou City and west of Zhangzhou City had medium climate similarity with Gaoxiong City. Also most counties in the west mountain areas of central Fujian Province (Jiufeng Mountain, Daiyun Mountain and Boping Mountain) had poor or no climate similarity with Gaoxiong City, which implied that the west mountain areas were not suitable for the cultivation of tropical and subtropical fruit trees from Taiwan Province. The other counties of Fujian Province had relatively poor climate similarity with Gaoxiong City in Taiwan Province. In these regions, tropical and subtropical fruit trees introduced from Taiwan Province needed to be cultivated in protective fields. (2) The distributions of annul mean temperature, mean minimum temperature in the coldest month (January) and extreme minimum temperature of previous years were similar to the distribution of the total value of the fuzzy similarity priority ratio of agricultural climate between Gaoxiong City and the 67 counties in Fujian Province. Central south coastal counties of Fujian Province had relatively high similarity, while the inland counties had poor similarity. (3) The climatic factors (except for annual precipitation) of central south coast of Fujian Province, especially the south coastal counties, had high climate similarity with Gaoxiong City. (4) For fruit tree cultivation, it was feasible to study the climate similarity between Fujian Province and Gaoxiong City using the fuzzy similarity priority ratio method. The results of the study offered useful and scientific basis for optimizing the distribution of fruit trees introduced from Taiwan to Fujian.