Abstract:

【Objective】 Castanopsis sclerophylla is an evergreen broad-leaved tree species of the Fagaceae family. It is widely distributed in the provinces and regions south of the Yangtze River and north of the five mountains in China. It is regarded as the “Dividing tree” of the climate in the south and north of China. It is important to study the changes in the potential geographical distribution of Castanopsis and its response to climate change for the protection and utilization of its wild resources. 【Method】 In this study, the MaxEnt model was used to simulate and predict the potential distribution areas of Castanopsis during the last glacial maximum, in modern times, and in 2070, and to evaluate the impacts of different climatic factors on its potential geographical distribution. 【Result】 ① The accuracy of the MaxEnt model in simulating the modern distribution area is very high, and the area under the working characteristic curve (AUC value) of the subjects was 0.971. ② The modern day highly suitable area for Castanopsis is mainly the mountainous area of south Anhui, namely the Dabie Mountainous areas, Tianmu Mountain and the hinterland of north Yandang Mountain. The moderately suitable area is located in the mountainous area of southern Jiangsu, namely the coastal area of Jiangxi and Fujian. The distribution during the last glacial maximum was mainly in the south and north of China and east of the continental shelf of the East Sea. It was predicted that in 2070, the distribution of Castanopsis will be affected by climate and the habitat will be fragmented. The highly and moderately suitable areas were predicted to remain in the high-altitude areas. ③ The Jackknife test showed that rainfall and average temperature in the driest season are the most important climatic factors affecting the geographical distribution of Castanopsis sclerophylla. 【Conclusion】 The effects of different climatic factors on the potential geographical distribution of Castanopsis sclerophylla can provide a scientific basis and guidance for provenance protection, habitat restoration, breeding, and domestication of Castanopsis.

Key words: Castanopsis sclerophylla, potential distribution area, MaxEnt model, climate change, phytogeography