Species diversity and geographic distribution of wild Orchidaceae in China

Abstract

China has the richest Orchidaceae species diversity in the world, and all orchid species are protected by the National Key Protected Wild Plants List and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). To understand and protect orchids in China, we analyzed their species diversity and geographic distribution based on a species list and geographical distribution database. There are 187 genera and 1447 species of orchids, including 601 endemics in China, and life forms are predominantly edaphic and epiphytic types. Orchids are concentrated in the southwest and Taiwan regions of China and are especially abundant in the eastern Himalayas, the Hengduan mountains, Xishuangbanna, eastern Yunnan and western Guangxi, eastern Taiwan, southern Hainan, along the border of Guizhou and Guangxi, western Hubei and eastern Chongqing, and on Funiu mountain in the Qinling area. Those regions also have a high rate of flora differentiation. Relatively, the geographical distribution pattern of endemic orchids is completely different from the overall pattern for orchids in China, particularly in the regions nearest to the southwest border. Regions with a higher percentage of endemic orchids are scattered across the country, and many areas of lower richness have greater endemicity. Finally, we identified 18 hotspots for orchids using a complementary algorithm, those areas represent 75% of all orchids in China and generally overlap with global biodiversity hotspots. This study provides an important foundation for prioritizing protection measures for wild orchids in China.