Chengdu Shahe Riparian Plant Community Structure Features And Its Relationship With Belt Width

River is an important natural factors influence the distribution of the city, and at the same time, the river corridor has very important economic, ecological and social benefits, and other functions, the riparian zone research has become the focus of ecology and environmental protection. Urban river play an important role in the construction of city.Shahe is the main river flows through the urban area of chengdu, mainly to supply water to the water in the east suburb of chengdu, as well as the main drainage channels, Shahe reform since2001has been used nearly natural way to conduct business, after the completion of the vegetation community has been more than ten years, after the completion of the proven its community structure characteristics, species diversity, evenness, abundance), corridor width relation with vegetation community structure characteristics, in May2012to September2012, apply the typical sampling metho dsurveys the Shahe riparian zone vegetation condition (in sample area, trees using each wood gauging, shrub and herb), Shahe river belt width, were set up60typical sample area. Main conclusions are as follows:(1) Chengdu Shahe plant community species mainly there are104families,161genera,179species, including trees,32species, belonging to27genera and20families; Shrubs53species, belonging to37families,46genera; Herb94species, belonging to47families,88genera. Affiliate of statistical analysis, sample survey to less concentrated in the genus and species, in the composition of the high dispersion; From statistical analysis, less sample area plant families in families and a relatively concentrated on a single branch, at the same time in rosaceae, gramineae, compositae and occupies a relatively large proportion.(2) The tree species present in DBH level and high level "two head, more than the number of distribution pattern of plant communities in different layers, Margalef index of species richness presented the shrub layer> herb layer> tree layer, the characteristics of tree Margalef abundance index is4.27, shrubs to13.30, the herb was7.16, in terms of overall study area plants, Shannon wiener diversity index-the general trend was shrub layer> herb layer> tree layer, the tree layer of Shannon wiener index was2.91, the diversity of the shrub layer number is3.60, the diversity of herb layer index was3.22. The shrub layer and herb layer of Shannon Wiener index of more than3, less than4-5of subtropical evergreen broad-leaved forest, Pielou evenness index overall performance tree layer> shrub layer> herb layer, trees of evenness index is0.86%, shrubs to0.79, herb of0.48.(3) All Chengdu Shahe vegetation species accumulation and accordingly the relative frequency of fitting curve (R2=0.9746, P<0.001=and the intersection point of straight line y=100-x (30.0,70.0) and the stability of ideal point (20,80) reached relatively close, conclude that the corridor of vegetation community structure is relatively stable.(4) The width of riparian zone and the tree layer, shrub layer material diversity and species richness has certain positive correlation. Width of tree layer, species diversity and richness that when the zone is less than12m, the zone of the edge effect obviously, width and the tree layer species diversity had no significant relationship between (R2=0.104, P>0.104), when the Banks of the river corridor width in12-30m and there are obvious correlation between the tree layer species diversity index (R2=0.373, P=0.373), when the width of riparian zone>30m with tree layer species diversity has no obvious correlation (R2=0.230, P>0.230), and the corridor width of riparian vegetation diversity, community structure has significant effect to the width of the riparian zone can partly eliminate the fringe benefits, to maintain the population diversity and stability of the high. The In the management of riparian zone, should be appropriate to consider a certain extent, increase the width of riparian zone, are beneficial to the function of riparian zone vegetation, has the vital significance for the protection of the ecological rivers.