Study On Geographic Distribution Pattern Of The Wild Orchidaceae Plants In China

Understanding biodiversity patterns and the formation mechanisms has long been the focus of ecology and biogeography. The abundance of large-scale geographic patterns of species of China’s seed plants has been made a lot of results, but few studies on the geographic patterns and formation mechanisms of orchid for the conservation of biodiversity and knowing of China’s wild orchideaece plants conservation are very unfavorable. We used geographic information system (GIS) to analyze the China’s wild orchidaceae plants of the geographic distribution pattern, based on the distributuion information collected from published literures and specimen records. In view of natural and social factors, the main driving force that caused the distribution pattern was explained, Major results are as follows:There are 1447 speices of China’s wild orchideceae plants listed (including subspecies and varieties), belonging to 187 genera, among them 203 species are listed as state protected category I and 1244 as category II. The floristic characteristics of China’s wild orchideceae plants are of extreme diversification and ancient origin, tropical nature are significantly dominant in genera, with obviously temperate floristic elements, and have higher endemism ratio.The distribution range of China’s wild orchideceae plants is very wide, species richness show a decreasing trend of richness from south to north, and concentrates in the southwestern regions and Taiwan of China. At the provincial level, the highest level area of species richness is Yunnan, followed by Taiwan, Sichuan, Guangxi, Tibet, Guizhou and Hainan; the richness pattern of endemic species is consistent with overall species, the highest area of Yunnan, Sichuan, Taiwan, the second highest area of Guizhou, Guangxi and Tibet. At the county level, there are four counties contained more than 200 kinds, namely, Mengla, Menghai, Jinghong and Gongshan, in which Mengla is the highest with 276 species; the distribution range of endemic species is relatively narrow, with highest values (richness and ratio) mainly in the south of Qinling mountains and Huaihe river and lower near national borders and continental edges.The life form of China’s wild orchideceae plants is complete, the distribution range of terrestrial orchids is very wide, and concentrates in the southwestern regions and Taiwan of China, the northern provinces also has a certain proportion; the epiphytic orchids only distributed in the south of China, Especially in Yunnan, Tibet, Guangxi and Guizhou; the Saprophytic orchids distribution areas in china is less, scattered in the moist humus-rich mountains of southwestern regions and Taiwan of China.Overall species (100%) can be found in 129 counties, as revealed by the algorithm based on the principle of complementary used by Dobson et al. (1997), meanwhile, by comparing the map of national nature reserves, most of the hot counties outside of the national nature reserves, these gap regions mainly distributed in the southwestern regions and border of province in China, these areas should be the hotspots in the aspect of protecting China’s wild orchideceae plants.At 100 km* 100km level, Species richness is consistent with overall species at county level, species richness shown a decreasing trend of richness from south to north and exhibited obvious latitudinal gradients. Exploring the relationship of the large-scale patterns of species richness and their environmental factors and human activities in China using eigenvector-based spatial filters models (SEVM), temperature seasonality, min elevation, precipitation of coldest month and road destiny may work together and best explain patterns of wild orchideceae plants species richness in China. The results show that the intensity of human impacts had effects on species richness patterns of China’s wild orchideceae plants, Our results provide some reference implications for conservation of wild orchideceae plants.