Climate suitability regionalization for Taiwan green jujube introduction and expansion in Fujian Province using GIS

In order to reasonably utilize climatic resources and optimize Taiwan green jujube plantation layout in Fujian Province, regionalization of the suitability of climate for the introduction and expansion of Taiwan green jujube in Fujian was conducted using GIS platform. Based on local meteorological conditions, lifecycle and production management characteristics of Taiwan green jujube in Fujian, an indicator system for the regionalization of the suitability of climate was constructed. The indicator variables included the annual cumulative temperature≥10℃, mean annual temperature, extreme minimum annual temperature (with climate suitability guarantee of 90%), annual precipitation and annual sunshine hours from 67 meteorological stations in Fujian Province during 1971-2011. The climate suitability index was summed up after standardization disposal of the performances of the five indicators and weighing by expert evaluation and AHP methods.Finally, the regionalization of the suitability of climate for the introduction and expansion of Taiwan green jujube in Fujian Province was done in GIS environment using the small grid reckoning models of the five indicators, combined with equation of the climatic suitability index. The climatic suitability index was divided into three grades, including suitable, sub-suitable and unsuitable, by natural break method combined with field investigation and repeated test. The reliability of the results of the regionalization of the suitability of climate for the cultivation of Taiwan green jujube in the province was confirmed by related research and the existing state of Taiwan green jujube plantations in Fujian. The results showed:1) coastal areas south to Quanzhou City and several other counties inland of Zhangzhou (Zhangpu County, Yunxiao County, Zhao'an County and Dongshan County) were suitable for Taiwan green jujube cultivation. Heat conditions in the areas were abundant, with annual cumulative temperature≥10℃ of >7 000℃, which prevented frost damage to Taiwan green jujube in the areas. As a result, Taiwan green jujube cultivation in the above areas could ensure high quality and yields. 2) Coastal areas in the central Fujian Province and some towns in Yongding County and Shanghang County in the south of Longyan area were the sub-suitable regions for Taiwan green jujube cultivation, because of lower extreme annual minimum temperature (with climate suitability guarantee of 90%) in the areas (0-4℃). It was possible that Taiwan green jujube cultivation in the areas could be hampered by low temperature or frost damage. Therefore, it was need to take defensive measures to avoid low temperature or frost damage. 3) The other regions/counties were unsuitable. The general climatic conditions in the areas were not fit for the growth of Taiwan green jujube, thus cultivation had no obvious economic benefits. Recent research studies and state of cultivation of Taiwan green jujube in Fujian confirmed the reliability of the regionalization analysis. The results offered a critical reference base for the introduction, expansion and adjustment of cultivation structure of Taiwan green jujube in Fujian Province.