Research On Flora Geography Of Seed Plants In Wolong Nature Reserve

The flora is a general name of all plant species of a certain genus or a certain family or a certain vegetation during an area or during a geological period, they reflect geographical environment in the different geological periods, they are the witnesses or the basis for environmental change. Wolong Nature Reserve is a national nature reserve, in the flora divisions its flora belongs to the region of the Hengduan mountains, it is one of the hot spots of the study of global biodiversity. In the research, there are two aspects, the statistic analysis to the species, genus, family and life form in the flora and the spatial pattern analysis to the life form and the geographical component of the species. through the investigation, statistics and analysis, the author preliminarily reveals the floristic characteristics and the geographical features of vegetation of the seed plant flora in the area, the research provides an important scientific basis for the protection of the species diversity and ecosystem diversity, the research has several conclusions as follows:(1)the flora is rich: the 1422 seed plants belong to 580 genera, 132 families, the total of the species, genus and family of the flora respectively account for 5.21%, 18.13%, 39.17% of the total of the species, genus and family of the national seed plants. the richness of the flora is connected closely to the landlocked mountains subtropical climate. the obvious vertical belt of the climate causes a diverse ecological environment which is conducive to the diversification of seed plants.(2)the predominance of the flora is obvious: the total of the dominant families and the total of the dominant genera respectively account for 9.1%, 2.58% of the total of the families and the genera of the flora, while the total of species of the dominant families and of the dominant genera respectively account for 50.00%, 17.16% of the total of the species of the flora; besides phanerophyte and geophyte are two main life forms in the flora, the total of the two life forms accounts for 69.27% of the total of the species of the flora.(3)the geographical component of the flora is complicated: the 1422 seed species are divided to 12 distribution types and 8 distribution variants, there are not only tropical components which accounts for 6.18% of the total of the species (except for the distribution type of the cosmopolitan) of the flora, but also temperate components which accounts for 39.73% of the total of the species (except for the distribution type of the cosmopolitan) of the flora, so the nature of the flora is mainly temperate. In the temperate components the distribution type of the temperate Asia and the Sino-Himalaya(SH) respectively are the first and the second, all these show that the flora is closely related to the warm ancient Mediterranean flora and the Himalayan orogeny.(4)the flora endemism is obvious and crossed: the total of the distribution type of the endemic to China accounts for 54.09% of the total of the species (except for the distribution type of the cosmopolitan), so the flora endemism is obvious. Besides, the distribution types and the distribution variants of the endemic to China to some extent also reflect the distribution feature of the endemic to China, firstly the distribution type of the endemic to China is unbalanced and regionally different, secondly it has obvious orientation, the flora show the characteristics of convergence with the northwest, north, northeast, central, eastern, southern and eastern Himalayan flora..(5)the distribution type of the endemic to China not only have ancient but also have new endemic components: The complex mountain environment of the area makes the ancient endemic components to find refuge to preserve and continue to develop, it makes the new endemic components to have hotbed to form and develop; besides, compared to the western Sichuan in the seed plants flora in the Wolong Nature Reserve the Ancient Mediterranean relict elements has a greater proportion in the endemic elements.(6) the trend of the ratio of the distribution types and the distribution variants along an altitudinal gradient are broadly in line with their geographical distribution properties. Most tropical distributions and their variations of the flora have developed in the sub-tropical climate and only under the conditions, most of the temperate distributions and their variations of the flora have at least developed to the cold weather conditions. Besides, the balance between the distribution type of the tropical and the temperate flora composition exists in a certain altitude location below 1600 meters.(7)the vertical distributions of the life form reveal that the life form is the long-term result of the plant adapting to the climate. Ph represents the warm and humid environment, Ch represents the alpine cold environment, H represents the temperate coniferous forest environment, G represents the damp cold environment, Th represents the tropical environment.