Studies On Forest Plant Diversity And Key Protected Plants In Sanjiangyuan Nature Reserve

Sanjiangyuan nature reserve is located in the hinterland of Qinghai-Tibet Plateau. It is the source catchment of the Yangtze River, the Yellow River and the Lantsang River and has been described as the "Water Tower of China". The flora and the vegetation types are inimitable because of high altitude and cold climate. In this paper, we researched the flora, the vegetation types, the endangered situation and the conservation classes of the plants in Maixiu forest region, Makehe forest region and Baizha forest region which belong to the source areas of the Yellow River, the Yangtse Rive and the Lantsang River respectively. The results are as follows.(1)There are 273 species in 44 families and 143 genera in Maixiu forest region. The flora of this region is characterized by North Temperate, the proportion 53.9%. The analysis of families and genus indicates that the structures of corresponding class community of vegetables both in Maixiu and Qinghai are identical basically,more than half of the vascular plants belongs to some worldwide families which have plenty of species, such as Compositae, Rasaceae, Ranunculaceae, Leguminosae, Gramineae and so on. There is the vegetation of 12 forms which belong to 4 groups of vegetation type and 5 vegetation types in Maixiu forest region. The research of the endangerment class of the plants shows that there are 1 endangered species, 6 vulnerable species, 19 near threatened species and 247 safety species. The analysis of the protection categories of the plants shows that the species number of the first concern category is 1, the second category 12, the third concern category 24, and the least concern category species 236.(2) There are 364 species in 55 families and 173 genera in Makehe forest region. The proportion of North Temperate is 47.3%. There is the vegetation of 22 forms which belong to 4 groups of vegetation type and 6 vegetation types in Makehe forest region. The research of the endangerment class of the plants shows that there are 2 endangered species, 6 vulnerable species, 12 near threatened species and 344 safety species. The analysis of the protection categories of the plants shows that the species number of the first concern category is 2, the second category 9, the third concern category 23, and the least concern category species 330.(3) There are 268 species in 47 families and 144 genera in Baizha forest region. The proportion of North Temperate is 48.6%. There is the vegetation of 9 forms which belong to 3 groups of vegetation type and 4 vegetation types in this forest region. The research ofthe endangerment class of the plants shows that there are 1 endangered species, 5 vulnerable species, 17 near threatened species and 245 safety species. The analysis of the protection categories of the plants shows that the species number of the first concern category is 1, the second category 7, the third concern category 19, and the least concern category species 241.(4) The comparison analysis of the 3 forest regions shows that Compositae, Rasaceae, Ranunculaceae, Leguminosae, Gramineae, Cyperaceae and Scrophulariaceae are the commonly dominant families which list on the former 10, and Potentilla, Saussurea, Astragalus, Pedicularis, Carex are the commonly dominant genera. The north temperate zone components are preponderant, Picea, Abies, Betula and Sabina are the constructive species or the dominant species in most of the forest vegetations in the 3 regions. The ratio of the herbs in Baizha region is the highest, and the ratio of the wood and the arbor is the lowest, while these ratios are very near in Maixiu and Makehe region.