Study On The Coupling Relationship Between Soilsfauna And Environmental Factors In Nanniwan Wetland

Objective: study the dynamic change of soil animal community and the responding mechanism of soil physical and chemical factors in different damaged wetlands.Method: The 6 sampling points in Nanniwanwetland Yan’an city Shaanxi Provinceare March,June,September and December in 2015,selected different damaged state of 6 samples of wetland respectively: Non degraded wetland-Mild degraded wetland-Moderate degraded wetland-Severely degraded wetland-Cultivated wetland(farmland)-Farmland returning wetland sample(recovery).Combined the surrounding soil environmental factors(soil organic matter,total nitrogen,total phosphorus,total potassium,test weight,p H)with taking the distribution of soils fauna In the field survey and observation and sampling analysis.For the further study of soil animal to soil environmentchangesto obtain the theoretical basis According to the analytic study,the results are as follows:This paper analyzes the effect between soil animal and environmental factors in different damaged wetland in Nanniwan Yan’an city Shaanxi Province,where dominant groups of soil animal includes a spider,springtail and nematodes,the number of individuals is very large,these groups together form the basic composition of the soil animal in Nanniwan wetland.The vertical distribution of soil animal of Nanniwan wetland appears table cohesion heterogeneous distribution in the number and variety,groups of soil animal of table cohesion is stronger than the number of individual table cohesion of soil animal.Combined with the soil animal community in different depth of Nanniwan wetland diversity index to analyze,seasonal dynamic changes will affect soil animal groups and individual number composition in Nanniwan wetland.With the change of seasons,some soil animals will migrate to change the environment of their living activities,which causes the seasonal fluctuation of the vertical distribution of soil animals.Seasonal variation of soil animal community diversity in Northern Shaanxi Nanniwan wetland is: Autumn is greater than summer,summer is greater than spring and spring is greater than winter.The seasonal variation of soil animals community is small,and some of the dominant groups could cross over several seasons.Therefore,the evaluation of the diversity of soil animals in the dynamic change of seasons is mainly based on the number of individuals,the Nanniwan wetland soil animal community composed of time heterogeneity is relatively low,the similarity coefficient is relatively high.The Nanniwan wetland soil animal is divided into different functional groups,in order to study the distribution variation law of different functional groups in different damaged wetland,form the regulatory mechanism of soil animal functional groups to damaged wetland ecosystem.According to a comprehensive analysis of the relationship between the Nanniwan wetland soil animal community structure and the physical and chemical factors,a systematic study was conducted to study the seasonal variation of soil environmental factors in different damaged wetlands.The correlation between the individual total number of small and medium soil animals and soil environmental factors was relatively close in Northern Shaanxi Nanniwan wetland.There was no significant correlation between the number of large soil animals and soil environmental factors,there was a negative correlation between p H value and soil water content and the number of animal groups and the total number of individuals.The content of organic matter was the most important index to reflect the richness of soil animal,the relationship between total N and total P content was significantly correlated with soil animal diversity,but the correlation was not significant.The total K content was not related to the diversity of soil animal.Conclusions: In different damaged wetland,soil damaged degree is smaller,the number of soil animal groups and individual total number are larger,the structure is more complex,its diversity and richness index is also relatively higher.In the non degraded wetland,the number of soil animals groups and individual number are large,the diversity,evenness and richness index are higher,it shows that the soil environmental conditions are superior and the degree of human disturbance is low.The cultivated wetland is mainly farmland,the structure is monotonous,and the degree of damage is larger,so the number of soil animal groups and individuals are less,and the diversity index are lower.With the increase of the degree of damage of different types of wetland,the number of soil animal groups and individuals are also getting lower and lower,the content of organic matter in the environmental factors has a very good reflect to this variation law.