Research On Cegetation Characteristic Under Water And Soil Distribution

By the data collection of surface water and vegetation and soil characteristics ofDongping Lake in2011~2012, analyzes the salinity and nutrient distribution in spatialand temporal of Dongping Lake`s surface water, lakeside zone`s soil salinity and nutrienttransport law and the composition and distribution of vegetation. And discuss therelationship between water and salt variations and the vegetation distribution of the lakewetland zone. The results show:（1）Surface water features: From the time perspective of the spring-summer-autumn, the variations of different soluble salt concentration is inconsistent in DongpingLake surface water, but is gradually increasing. But the conductivity, salinity, salinitychanges with the seasons and reduced.The water of Dongping Lake is weaklyalkaline,and the pH fluctuates in the range of8.37-8.98.The soluble cationic componentof the water changes little with the seasons,while the anionic component is slightlychanged from SO42->Cl->HCO3-into SO42->HCO3->Cl.Lake`s nutrient showes someseasonal variation:the nitrogen cycle shows smooth transformation in spring andautumn,but dramatic transformation in summer.Spatially speaking,the levels of solublesalt ions,total nitrogen and total phosphorus decrease generally from the estuary to theexport of the lake;The salt content of Daotunwa is significantly higher than the lake.（2）The soil characteristics of the lakeside:The content of the soil nitrogen is smallin the estuary and the export of the lake,but is higher in the east and the southeast of thelake.Overall the total phosphorus contents of the soil is very low,but it is slightly higherthan the other regions in the estuary.It is low levels of soil total K in the estuary,higher inthe export of the lake.The soil salinity shows that the southeast region of the lakeside<theestuary<the export. Overall,the contents of the soil salinity and nutrient is lower in theestuary,the nutrient is higher in the eastern and the southeastern,and the soil salinity ishigher in the export.In addition,the salinity and nutrient of the soil in Daotunwa also showed higher levels.The distribution of the total phosphorus and organic matter in thevertical is more significant in the lakeside,and the deeper the soil, the less the contents.Theorganic matter content near the lake is greater than the distance.（3）Vegetation characteristics and the coupling relationship:The vegetation cover ofDongping Lake wetlands showes a high level from spring to autumn,and the vegetationcomposition is varied.The plant diversity in the lake wetland is higher than the Daotunwawetland,but the uniformity slightly lower.That has a relationship with the regionaldistribution of water and salt.The vegetation can be divided into four groups in DongpingLake survey area under the influence of environmental factors.ⅠOligohaline-less watergroup，Ⅱlow salt-mesophyte，ⅢHalophilous-mesophyte，ⅣHalophilous-more watergroup.