The Research On Woody Flora Of Tongdao County, Hunan

Tongdao county is situated in southwest of Hunan province . It connects with Guizhou and Guangxi province, extending from 25°52' 00"—26°29' 20" N, 109° 25' 51" —110° 00' 50" E, with an area 2239km2. According to Wu Zhengyis theory about flora, many species of different provinces penetrate here, and also lots of antiquated species centralize, so the flora is complex. On the basis of former large investigation, collection and identification of specimens, reference of literatures, this paper discusses the floristic structure, character and adscription of flora, and analyses the flora in different level of family, genus and species, also analyses the function of the woody flora to the flora of Hunan province. Based on the statistics, the analysis results as follows. 1. There are 7 types of vegetation in the county, including almost 27 formation types. 2. 107 families, 366 genera and 1010 species of wild woody plants are recorded in the county, and of these families, genera and species, there are 8 families, 13 genera and 18 species in Gymnospermae, 99 families, 343 genera and 992 species in Angiospermae. So the floristics is abundant. 3. The famous rare bequeathable species, such as Gingkgo biloba, Cephalotaxus oliveri, Amentotaxus argotaenia, Pseudotaxus chienii, locate here, and there are also some species with carpels apart from each other, which embody the antiquated character of the flora. 4. The geographical ingredient of flore is multiplex. Of the total 15 distributing types of statistics, there are 10, 14 and 10 types of representation in family, genus and species level. We can know, through the statistics of species locating only in China, that the amount of species in common between the county and Centre-China province is the largest, at the same time, the amount in common between the county and South-China, East-China, Southwest-China is also larger. 5. The quality of the flora is subtropic. According to the distributing types, the ratio of tropical types(temperate types) is 56. 0%(28. 0%), 53. 2%(46.8%) and 21.8%(15. 8%) in family, genus and species level. 6. The flora belongs to Centre-China province and Yunnan-Guizhou-Guangxi province, and the dividing line is Quangshu mountain—Yutang—Zhutang—Longchen—Badoupo—Xiazhai village—Wulangpo...