Study On Soil Collembolan Community Structure And Diversity In Bidirectional Successions Of Sanjiang Plain, China

Soil animals are one of the most important part in wetland ecosystem. They can participate in the whole ecosystem process, such as material circulation and energy flow. Collembola, as one of the three main soil fauna(collembolan, mites, nematodes), can alter their community structure and diversities with the changes of ecosystem. Collembola can influence physical and chemical properties of soil organic matter. The structure, function and succession of ecosystem can be changed through the survival, reproduction, feeding and other activities of the collembola.Three reclaimed(to soybean fields) and three restored(from soybean fields) wetlands were selected to investigate the effect of bidirectional succession of wetlands change on community structure and diversity variation of Collembola.We also analysed the relationship between the community sturcuture and the environmental factors. This study was conducted in the Sanjiang plain swamp wetland ecological experimental station of Chinese academy of sciences. Using different space to represent different time periods, native wetland(YS), 2 years reclamation(NG2), 15 years reclamation(HX), 25 years reclamation(HJ), recovery for 6 years(HF6) and recovery for 12 years(HF12) were choosed as samping fields. Soil moisture content, soil p H, soil organic matter, soil total carbon, soil total nitrogen, soil total phosphorus were determined to analyze the relationships between springtails community structure and environmental factors in the process of bidirectional succession of the sanjiang plain wetland. The results show that:1. 28723 springtails, belonging to 30 species, 16 genera and 8 families were captured in soybean field. The Lepidocyrtus Felipei, Onychiurus allonychiurus, Onychiurus oligaphorura, Onychiurus protaphorura as the dominant species, accounted for 80.56% of the total. Common species including Desoria sp.2, Folsomia sp.1, Folsomia sp.2, Folsomides sp.2, Hypogastrura sp.2, Isotomiella sp.1, accounted for 13.90% of the total collembolan community. Rare species including Arrhopalites blind and other 20 kinds, accounted for 5.54% of the total collembolan community. Short-term(2 years) reclaimed farming could increase the density and diversity of springtails. Medium reclaimed farming(15 years) could reduce the density and diversity of soil springtails in the soil. With cultivating years going on, soil ecological system will reach a new balance and the ecological index reach a new high level.2. 21842 collembolan, belonging to 31 species, 16 genera and 8 families were captured during the restoration process of wetland. Folsomides sp.2, Onychiurus allonychiurus, Onychiurus oligaphorura, Onychiurus protaphorura as the dominant species account for 54.27% of the total collembolan community. Common species including Arrhopalites blind, Bourletiella sp.1, Desoria sp.1, Desoria sp.2, Desoria sp.4, Entomobrya sp.4, Folsomia sp.1, Folsomia sp.2, Hypogastrura sp.1, Hypogastrura sp.2, Isotomiella sp.1, Lepidocyrtus Felipei, Orchesellides sp.1, Tomocerus nigrus, accounted for 41.59% of the total collembolan community. Rare species including Desoria sp.3 and other 13 species, accounted for 4.14% of the total collembolan community. Restoring for 12 years from soybean farmland, soil springtails got the highest density and diversity. Native wetland had less collembolan density and diversity, HF6 has the lowest level. Those wetland restoration measures can significantly improve the farmland environment and even better than the native wetland.3. The density and diversity of springtails and their relationships with soil environmental factors in these fields were analyzed through Redundancy Analysis and Canonical Correspondence Analysis. The results showed that there was closely relationship between collembolan and the environment factors. The soil moisture content, soil p H, soil organic matter, soil total carbon and soil total nitrogen were closely related to the distribution of springtails during two-way succession process. The changes in soil moisture, soil organic matter, total nitrogen, total potassium and total phosphorus tended to be approximate, whereas the change in soil p H was just opposite.