【目的】苦槠(Castanopsis sclerophylla)为壳斗科栲属常绿阔叶树种,广布于中国长江以南五岭以北各省区,被视为我国南北方气候的“分界树”。研究苦槠潜在地理分布格局变迁及其对气候变化的响应对于保护其野生资源具有重要意义。【方法】运用MaxEnt模型,模拟和预测苦槠在末次盛冰期(last glacial maximum, LGM)、现代和2070年3个时期的潜在分布区,评估了气候因子变化对其潜在地理分布的影响。【结果】MaxEnt模型模拟现代分布区准确度极高,受试者工作特征曲线下的面积(AUC值)达0.971;苦槠现代高度适宜区主要是皖南山区、大别山区、天目山至北雁荡山地区;中度适宜区扩展到了苏南山区、江西及福建沿海地区;末次盛冰期退缩分布在我国华南北部地区,以及东海大陆架东部。2070年,苦槠的分布受气候影响预测适生区会急剧缩小,生境出现破碎化,高、中度适宜区残存于高海拔地区。Jackknife检验表明,最干季降雨量、最干季均温是影响苦槠地理分布的最主要气候因子。【结论】探讨不同气候因子对苦槠潜在地理分布的影响,利用其生物属性监测亚热带最北缘范围动态变化,可为苦槠的种源保护、生境恢复、繁育驯化等提供科学依据。

【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.