Research Of Relationship Between Nitrogen And Phosphorus Accumulation And Biomass Of Rhizospheric Microorganisms Of Wetland Plants

Constructed wetlands as a unique ecosystem, which has unique form and characteristic and ecological function, play a huge advantage in controlling of surface and point source pollution of Lake. Now, the studies of the wetland system are mostly concentrated in purification mechanism, purification effect, process structure, selection of wetland plant and so on. While, research of relationship between pollutants absorption and utilization of wetland plants and rhizospheric microorganisms is scarcity, and whether there are coordinated metabolic activities between them is not clear. So, the objective of this work was the relationship between nitrogen and phosphorus accumulation and biomass of rhizospheric microorganisms of Zizania caduciflora, Phragmites communis, Scirpus validus, Cyperus papyrus, Canna indica, Iris germanica, Acorus calamus, Thalia dealbata, Pontederia cordata and Typha angustifolia, and which contact with the research of wetland restoration and its demonstration technology of Miju River estuary situated at the northern of Erhai Lake, and provide reference for wetland model engineering of design, and construction and running. The results of this paper as following:(1) Basically, in autumn, nitrogen and phosphorus accumulation of wetland plants reach its maximum; and the maximum of10species of plants is Thalia dealbata, they are30.15g/m2and6.92g/m2, but is the Canna indica is the minimum, the are8.42g/m2and0.62g/m2;(2) In general, the number of rhizospheric microorganisms of weland plants is increasing, the variation is first increase and then reduce with the seasons change in a year, and the order is bacteria> actinomycetes> fungi> nitrogen fixing bacteria;(3) The correlation between nitrogen accumulation of Scirpus validus, Thalia dealbata and Pontederia cordata and biomass of their rhizospheric microorganisms was found evidently positive, the coefficient is0.89,0.82and0.842(p<0.05); and he correlation between phosphorus accumulation of Scirpus validus, Thalia dealbata and Acorus calamus and biomass of their rhizospheric microorganisms was found evidently positive, the coefficient is0.93,0.925and0.9(p<0.01); while, the plants and rhizospheric microorganisms of wetlands were multiplely influenceed by the environment factors, and the level of correlation between nitrogen and phosphorus accumulation of Scirpus validus, Thalia dealbata, Acorus calamus, Pontederia cordata, Zizania caduciflora, Cyperus papyrus and Iris germanica and biomass of its rhizospheric microorganisms and environment factors were very high, in93.9%-99.9%;(4) In this test, Thalia dealbata was the dominant species, which could be selected priority when we will construct artificial wetland in Erhai, because of improving the biomass of rhizospheric microorganisms and eco-environmental benefits.