The Analysis On The Plant Communities Of Waterfront Of Changsha Under Realized Niche

There is an important guiding significance of Niche theory in the building of plants community, interspecific relationship as well as the adaptability to the environment of species,etc.In order to provide theoretical guidance for plant configuration of waterfront landscape, the niche characteristics and the landscape situation of waterfront plants of the Martyrs Park and Yanghu Wetland Park were invested and analysised, which based on realized niche theory.In the form of quadrat seting, the niche width and the niche overlap were chosen as indexs of niche characteristics. The ecological adaptability of plants and the collocation between the species of community structure were analysised on community gradient, moisture gradient and illumination gradient.The landscape-design strategy of waterfront plants based on realized niche theory were discussed from three aspects:the reasonable arrangement of plants with different niche width, the building of interspecific relationship based on resources complementary,the constructing of ecological layout in the view of security and stability.The results showed that:In comparison with other species of plant community,the wider niche width was the dominant one,which determined the appearance features.While the species with narrower niche width play an important role in maintaining community stability and improving the biological diversity.A total of 76 kinds of plants belonged to 61 families in the Martyr Park waterfront were investigated,including 24 kinds of arbor layer,23 species of shrub layer and 29 kings of herb layer, none liana.The differentiation ecological niche and the tendency of succession of waterfront plant communities in the Martyr Park was largely depended on the ecological adaptability of various species and the interaction between them. Niche overlap of the arbor layer,with higher degree on niche differentiation and the relatively stable interspecific relationship, was lower than the shrub layer and the herb layer of waterfront plant communities.The simplex appearance feature of plant landscape, a lack of multiple space of understory forests, the invaded phenomenon of shrub layer as well as the competition between species with higher niche overlap were exsisted in the Martyr Park.A total of 39 species belong to 25 families in sample area of the Yanghu Wetland Park,including 21 kinds of emersed plants,4 kinds of fluitante plants,5 kinds of floating plants,1 kinds of submerged plants as well as 9 kinds of herbage.The high plant desity, fast reproduction and the similar life form of aquatic plants in sample area resulting in a common phenomenon of niche overlap and a complexion about disrupting to the structure of plant communities by invasive plants.The applications of niche theory in plant community could be analysised from two aspects:the ecological adaptability of species and the interspecific relationship. The niche width of species indicated the certain niche boundaries of species and the adaptive capacity in plant community, which reflect on the distribution pattern of species.In some degree,the competition between different life-form plants is the competition of ecological niche.