Inter-specific Association And The Response To The Soil Factors Of Several Main Herbs In Chongming Dongtan Wetland Park

In order to explore the species association between several major herbs and their response to soil factors (soil moisture content and soil electric conductivity) in Chongming Dongtan reclamation area, our experiment investigated different plant communities in reclamation area from August 2014 to December 2015.One hand we investigated the herb community by the statistical method of Population biology, then we used rank correlation of inter-specific covariation to analyse the species association among these herbs.On the other hand we determinated the soil electrical conductivity and soil moisture by soil parameter metering device, then we used redundancy analysis to explore the relationships between plant communities and edaphic factors.Finally, we measured residual dry weight of the herbs litter regularly,and studied the decomposition dynamics of them.The experiment can provide theoretical basis for landscape improvement of the wetland park, and it can provide the data support for the conservation and restoration of native reed community of Dongtan wetland.The results obtained are listed as followings:(1) From the research we find that it has difference between soil moisture content and soil electric conductivity in Chongming Dongtan reclamation area, the soil moisture content is high in most areas(approximately more than 60 percentage), and the soil electric conductivity is low(below 1000ms/m). There are less species in the plant community, and its community structure is simple.(2) Among the fifteenth inter-specific relationship of six dominant species in the samples, eight species showed positive correlation, seven species showed negative correlation, there were 4 significant positive correlation and 1 extremely significant positive correlation, Aster subulatus and Suaeda glauca have a highly significant positive correlation(Spearman rank correlation coefficient is 0.782), and they occupy the area with higher rates of soil electric conductivity and lower rates of soil moisture content; Imperata cylindrica and Carex scabrifolia have a significant positive correlation(Spearman rank correlation coefficient is 0.604), and they occupy the area with lower rates of soil electric conductivity and higher rates of soil moisture content; but Phragmites australis have a negative correlation with most plants and have a obvious correlation with soil moisture content and soil electric conductivity.(3) Moisture and heat conditions play a key role in litter decomposition rate in the experiment, the decomposition quantity of litter have a great relationship with its physical morphology, and the mixture among reed and other plant litters do not produce significant mixed effects.Through the research all above, we have two suggestions for the park:On one hand, we can introduce more native herbs to strengthen the protection and construction of habitat for birds and wildlife, in order to improve the diversity of species and maintaining stability of the ecological system; On the other hand, we can establish a long-term stable monitoring database and used methods including wetland water restoration and artificial planting,to rebuild the native Phragmites australis pond landscape.