Study On Main Forest Community' Plant Spieces Diversity In Fengdu County

This paper started with the main forests in Fengdu county and aimed at the characteristic of this county's forest distributing and the law of the natural development, which were to discover the relationships of the plant diversity of different forests among the altitude, exposure, canopy density, source of forest and disturbance of human being. This paper made use of popular Shannon-Wiener indices and eveness indices to calculate the plant diversity indices of different forests or different layers, and compare the plant diversity of different vegetations and different forests. And these will provide some useful and logic evidences for studying the plant diversity in Three Gorges Area.According to feature of plants in Fengdu, the forests are disparted to six main forests categories and sixty-seven spots are set up. The survey is carried out basing on the Stat. items of tree, shrubbery, herbage in the spot. This was the first time to research on the vascular bundle plant diversity of Fengdu's main forests all-side and systematically.First, all forests' plant diversity indices are different in altitude factors. When the canopy densities are middle, the abundance indexes of Forest of Pinus massoniana is higher. Forest of Cuptessus funebris, Forest of Cunningghamia lanceolata, Forest of Cryptomeria fortunei, Forest of Quercus acutissima, Forest of Pinus massoniana, Cunningghamia lanceolata, have similar laws.Second, when the canopy densities are among 0.5 and 0.6, the abundance indices of the six forests plant: Forest of Pinus massoniana, Cunninggharnia lanceolata＞Forest of Pinus massoniana＞Forest of Cunningghamia lanceolata＞Forest of Cuptessus funebris＞Forest of Cryptomeria fortunei＞Forest of Quercus acutissima, while the Shannon-Wiener indices in the tree layers: Forest of Pinus massoniana, Cunningghamia lanceolata＞Forest of Cunningghamia lanceolata＞Forest of Pinus massoniana＞Forest of Cuptessus funebris＞Forest of Cryptomeria fortunei=Forest of Quercus acutissima.Third, The plant specimen are collected bv the integration of the sample survey and sample route and the data collected by former persons are also summarized, which make that the plant specimen can stand for the feature of the researched area. There arre 1691 species of vascular bundle plants which belong to 746 genera and 180 families totally. Among them the fern has 36 families, 70 genera 167 species and the gymnosperm has 9 families, 22 genera and 33 species and the angiosperm has 135 families, 654 genera and 1491 species.Fourthly, of all the areal-types of the seed plants genera in Fengdu county, most abundance distributed are North Temperate(107) and Pantropic(106), Endemic to China is 25 genera by study on them, the least distributed are Mediterranea. W. Asia to C. Asia(3) and C. Asia(1). Other areal-types are some unequally distributed.Fifthly, Among the 1691 vascular bundle plants, Phanerophytes has 1006 species, second the chamephytes is 453 while hemicryptophytes is 93 and cryphytes is 40. Therophytes has 93 species, which are close to the plant life-form spectrum of wetness climate of subtropic zone.Finally, there are 38 wild species which should be protected weightily and they belong to 27 families and 34 genera. Evergreen tree has 13 species, defoliation tree has 13 species, woody bine 3 species and herbages 9 species.As the Fengdu county is in the centre of the Three Gorges Area, the thorough research of the diversity of the plant is good for understanding of the plant protect state and improve the construct of the ecology and environment.