Qingcheng Mountain, Dujiangyan City, Sichuan Characteristics Of Forest Vegetation Ecology

The Qingcheng Mountain Scenic Spot is situated at 15km of southwestern of Dujiangyan city in Sichuan, at 1030351 E and 300541 N .It is one of national emphasis scenic spots issued by our country to the world, with a core area of about 1522ha. The paper studied on numerical classification, species diversity and interspecific association of the major species by adopting . - quadY- method and regarding altitude as dominant factor. l.A series of method including the tabular comparison of data, the tabular comparison of similarity coefficient, the nearest neighbor method and the group verage method of hierarchical agglomerative classification were used to deal with the forest communities on Qingcheng Mountain. From the results of the classification, the 11 forest plots on the Qingcheng Mountain were divided into two vegetation types and five formations according to the important value in the tree layer. Two vegetation types were evergreen broadleaved forests and warm conifer forests. Five formations included Cycobanopsis gauca + Symp]ocos aurina formation, Cyclobanopsis glauca + Gas tanopsis fargesii + Cunninghamia anceolata formation, Gas tanopsis fargesii formation, Lithocarpus harlandii + Micheia floribuno formation and Cunninghamia lanceo]ata formation. The most formations of evergreen broadleaved forests are in a stable stage, except a few indicated secondary characters because deciduous trees intruded communities under man effecting. If strengthen the management, these forests will restore to the former state. Cunninghamia lanceo]ate forests principally distributed the border districts of evergreen broadleaved forests that were disturbed by human being. The trees of Cunninghamia lanceolate didnt grow very well because many evergreen trees form shade, for the cause the warm conifer forests of the region will turn to evergreen broadleaved forests. 2. Based on the data of the plots, it was discussed about species richness, Simpson inde, Shannon iener index and Pielou index of the forest communities in Qingcheng Mountain of Sichuan Province. The results were similar variation when the four indices were used to measure species diversity of forest communities. The indices were compared for different vegetation types. Generally, the species diversity indices order was that shrub layer >tree layer >herb layer. The indices order was that evergreen broadleaved forests>warm conifer forests. Species diversity of tree layer decreased when the sea level of the region increased. But shrub layer and herb layer were not so clear as that of tree layer. Human being affected the species diversity of forest communities. 3. Base on the 2X2 contingency table, by means of different indices, the interspecific association among 20 common species in the forest communities on Qingcheng Mountain were investigated. The results indicated that there was remarkable positive correlation among the common populations from an overall point of view. The west indicated this correlation was significant. The most pairs of the populations in the forest communities on Qingcheng Mountain showed positive correlation, the x2est indicated there was almost no significance in the interspicific association. The independence of species pairs of in common populations was significant. The relaxation of the interspecific association is possibly related to the succession stages of communities of this region.