| According to methods of observing the relatively height of the landform, investigating plant replicates, observing the rainfall, evaporation, surface altitude and water level, in the rain season of 2006, this paper studies the terrain slop, the distribution of plant community and dynamics of evaporation and rainfall, and on the basis of this, analyses the effect of the dynamics of the water level and changeness extent on the dynamics of landform form and the distribution of plant community, and fringely summarizes the spacial coupling relation of the landform-vegetation complex, obtains the conclusions as followings:(1) In the peatland, from the river to the front of the hill, the relative hight of the landform increases gradually. With the surface altitude increasing, there can be divided into three plant community subareas: In the zonal area from 0 to 325m, plant community is Phragmites sustralis—Carex schmidtii community; In the zonal area from 325 to 500m, plant community is Carex schmidtii community; In the zonal area from 500 to 700m, plant community is Betula ovilifolia—Carex schmidtii Sphagnum palustre community. Along the three plant community subareas, the species richness and species diversity firstly decrease then increase, and ecological dominance firstly increase then decrease. For the whole peatland, Carex schmidtii is dominant species.(2) The singler the dominant species, the form of the hummock grow consistent, with the number of the hummock increase, surface roughness cofficient becomes small. And the higher the species richness, landform presents heterogeneity, and the fewer hummocks, the bigger the surface roughness.(3) The landform and water level of the peatland are influenced by rainfall and evorporation, and the landform is controlling the form of water level, and water level also restrict the change of the landform.(4) In July, August and September, rainfall first increase and then decrease, evaporation first decrease then increase. In July, the rainfall is continuous, in August, is high intensity but not continuous. In September, it is little. In a certain extent, following the increase of the rainfall, the water level decreses. In the same position, the water level is highest in August, the water level in September is the lowest. But as a result of the difference of peatland and the distribution of plant communities, there is no orderliness of the changeness of every point in the peatland.(5) The change extent of the water level and the falling extent the imbedded water level is the biggest in Phragmites sustralis—Carex schmidtii community, The reason is likely to be it's near to the river, and have gutters in the peatland which is near the river, which makes the water enter the river easily, and so make the change extent bigger. As the surface altitude increases, the water level and the imbedded water level decrease, and is lowest in Betula ovilifolia—Carex schmidtii Sphagnum palustre community, which may be firstly caused by the distribution of the hummocks of Sphagnum palustre, which is powerful in holding water, and this has cushion function on the change of water level; On the other hand, it may be caused by it's position near the hill, the runoff from the hill may supply the district, so that the change extent of water level at a certain extent minishes. The imbedded water level is affected by landform, vegetation and water level, and because there is no orderliness of the change of every point in the peatland, there is no orderliness of the change of the immbedded water level in the peatland. But the raising extent of the imbedded water level is the biggest in Phragmites sustralis—Carex schmidtii community, as the surface height increases, the raising extent decreases, but increases in Betula ovilifolia—Carex schmidtii Sphagnum palustre community.
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