Study On The Composition Feature Of Gardening Plant Communities In Main Urban Areas Of Chongqing City

Gardening plant communities defined as man-made type in the city are different from the natural type owing to the extent of man-made interference. Studies on gardening plant communities focused on floristic analysis, species composition, structural feature and ecological benefit these four respects have put forward plenty academic guidance for virescence job in the city. On the contray, the study for gardening plant communities has been taken lately in Chongqing. So the gardening plant communities in main urban areas of Chongqing city are discussed in this study. The differences between the man-made type and the natural type ( evergreen broadleaved forest in Jinyun Mountain ) are analysed on the basis of investigation for species composition and their structure, besides the ecological effect of communities are also mensurationed. The ecological rules for constructing gardening plant communities in main urban areas of Chongqing city are discussed at last.In this paper, gardening plant communities are firstly distinguished into three types in terms of the extent of the man-made interference: natural type, half-natural type and man -made type, as well as into park green space type, road green space type and campus green space type these three green space types. The differences between the man-made type and the natural type are discussed, and then the feature of species composition about the three green space types is contrasted. The species diversity and the ecological effect of different structural types are discussed at last.The main results are as follows:1. Species composition of trees. In man-made type communities, the dominant three families of arbor are Moraceae, Magnoliaceae and Lauraceae, whose quantities reach thirty-six percent of all. The quantities of dominant families in shrub also achieve sixty-three percent of all, and the quantity of Rhododendron obtusum actually reaches forty-seven percent of all. It shows that the dominance in shrub is much more distinct than that in arbor. On the basis of the feature of local vegetation, some species in arbor layer of Lauraceae, Magnoliaceae, Elaeocarpaceae, Fagaceae, Moraceae, Theaceae and...