关键词: 末次冰盛期, 全新世中期, 物种分布模型, 模型优化, 适宜分布区

Abstract: Camellia reticulata, a valuable wild winter flower plant species in Yunnan, has been listed as class Ⅱ national key protected wild species in China. C. reticulata has not been fully utilized in landscape applications due to its strict requirements for natural habitats. Climate change affects the distribution of plant species. Understanding the response of C. reticulata to climate change is the basis for its conservation, development and utilization. The distribution dynamics of C. reticulata from the Last Glacial Maximum to the end of this century was simulated with an optimal ensemble model (EM) in the Biomod2 package, based on climatic, topographic, soil and vegetational factors. The results showed that the optimal EM which composed of Generalized Boosted Models, Flexible Discriminant Analysis, Random Forest and optimized Maximum Entropy Models had better accuracy and performance compared to the single models, and being more simpler than the EM integrating by all model algorithms. Among the 31 environmental factors, temperature annual range was the main factors affecting the suitable habitat distribution of C. reticulata. Under the current climate scenario, C. reticulata is mainly distributed in the southwest China, south China and Taiwan, of which the highly suitable distribution region including most areas of Yunnan, southwestern Guizhou and northwestern Guangxi. Southern Cuona of Xizang, southeastern Fujian and southwestern Hainan also have scattered distribution of C. reticulata. Central region of Yunnan might be refugia site for C. reticulata in glacial age. With the warming climate, the suitable habitat of C. reticulata continues to spread to the surrounding four provinces. Future climate change would not cause large-scale migration or extinction of C. reticulata. Yunnan and its bordering provinces Xizang, Sichuan, Guizhou and Guangxi have always been stable and suitable areas for C. reticulata. The results indicated that global warming is conducive to the survival and reproduction of C. reticulata, and the suitable areas will spread northward. In the future, regions that are mainly considered suitable for introduction, domestication and gardening applications of C. reticulata would include northern Yunnan, southern Cuona city, southern Sichuan, southern Guizhou and coastal areas of Fujian.

Key words: Last Glacial Maximum, Mid-Holocene, species distribution model, model optimization, suitable distribution region