The Characteristic And Diversity Of Herbaceous Plants In Riparian Zone Of Taizi River In Liaoning

In this paper, the species of riparian herbs in Taizi River were investigated by using the quadrat method. The structural features of species were analyzed, including the basic composition of species flora, the geographic distribution of species flora, the features of quadrat species and the spatial distribution of species. The principal component analysis and regression analysis method were used to analyze the impact of the natural environment, river characteristics, the soil and the surrounding landscape on the plant diversity in Taizi River.1) There were altogether207herbaceous species in Taizi River belonging to36families and125genera, and Compositae had the most species among all families, while Polygonum hydropiper had the highest occurrence frequency. Geographic flora in this region was highly diverse, dominated by temperate genera and many from tropics genera. Of all species ecotype of120species is hydrophyte and hygrophyte and87is mesophyte and xerophytic covering58.0%and42.0%of all species individually.2) All samples were clustered into2types based on presence and absence of species, and one type distributed mainly in high altitude area whose dominate species was mesophyte and xerophytic, while the other type distributed mainly in low altitude area whose dominate species was hydrophyte and hygrophyte.3) The diversity of herb species distributes in riparian zone of Taizi basin variously, and generally appears to be heterogeneous significantly. It increases firstly and decreases secondly as the river flows from agricultural plain, through hilly forest, to mountainous forest simultaneously. It appears different in agricultural plain from in forest areas, however, differentiates not significantly within forest areas.4) The diversity of herb species is affected to various extents by different landscape factors and their distances to the herb. Significant effects of grass land only exists within the distance range of50 meter, and that of residential land are limited into distance ranges between100and500meter, and that of shrub forest distributes from100meter to200meter and distances over400meter. The effect of landscape layout on this diversity is mainly determined by the shapes of landscape factors.5) The elevation and percentage of shrub forest land could be considered as environmental directory indicator of herb species in Taizi River basin, and the diversity of herb species is sensitive to the pH value. The diversity peaks twice, even rarely ever seen, along with an increasing or decreasing elevation. The diversity could be changed both by the elevation and the environmental directory gradient, therefore, it could be affected much by human activities.