The Characteristic Of Soil Nematodes Communities During The Succession Process Of Wetland Plants Communities In Dalian Xishan Reservoir

The wetland is one of the most important ecosystems on Earth. Different patterns of wetland ecosystems formed after natural and anthropogenic succession. As the bioindicator of changes in the wetland ecosystem, soil nematodes had extremely important function of instruction. Dalian Xishan Reservoir Wetland lied in the ecotone of the city and the village, which changes influenced by natural and human factors. The characteristics and ecological indexes of soil nematode communities had been studied in the wetland ecological natural succession process and the succession of human disturbance. Here are the results:(1) In order to study the soil nematodes community characteristics of different vegetation types in the natural succession process,nematodes in the bare land,Calystegia-Humulus community,Phragmites hirsuta community,Phragmites communis Trin. community and Artemisia community were collected and identified.Diversity and the characteristics of the functional group of soil nematode in various stages of succession had been studied.The result of MI index and MMI index was:Phragmites hirsuta community>Phragmites communis Trin. community>Artemisia community>bare land>Calystegia-Humulus community,and MI2-5index was:Artemisia community>Phragmites communis Trin. community>Calystegia-Humulus communities>Phragmites hirsuta community>bare land. The MI and MMI index showed that the succession of medium-term was the most mature. The MI2-5index showed that the mature of soil nematode community stabilized with the succession.Comparing Phragmites communis Trin. community with burned Phragmites communis Trin. community was in order to study the impact of the fire on Phragmites communis Trin. community.There were significant differences between the two samples about TD index in10-20cm soil.The C index,H’ index,SR index and J index had significant differences in the summer0-10cm soil. The biodiversity differences of nematodes caused by fire on the0-10cm soil were the response of the changes of physical and chemical properties. PPI index had significant differences in0-10cm soil in spring. (2) In order to study the impact of the land reclamation, diversity and functional groups of nematodes community between farmland and Artemisia community has been compared. After land reclamation physical and chemical properties in different soil layers of Artemisia communities appeared significant differences in the fall. Soil nematodes, number of genera, ecological index had changed. Significant correlation occurred between organic matter and richness SR index. There were significant differences about SR index between the10-20cm soil of farmland and the0-10cm soil of Artemisia communities. The organic matter and El index had extremely significant correlation. And significant differences occurred in the El index in0-10cm soil in the fall.