Study On The Characteristics Of Soil Faunal Community For Clear-cutting Forestland In Zuojia Nature Reserve

The forest soil fauna which is an important segment of the forest ecosystem, plays an irreplaceable role in material circulation and energy flow. Cutting is an important part of the forest business activities. In clear-cutting forestland soil fauna community characteristic is usually used as an important index of soil fertility. This paper studied ecology characters, such as flora composition, dominant group, horizontal distribution and vertical distribution, of soil fauna and analyzed the relationship between soil physical-chemical properties and soil fauna in clear-cutting forestland and unclear-cutting forestland of Zuojia Nature Reserve, Jilin province. So that, it can provide soil faunal ecology theoretical basis for restoration and protection of clear-cutting forestland and forest sustainable development.In Zuojia Nature Reserve,4typical habitats, Mongolian oak+black birch forest, larch plantation, clear-cutting forestland of larch plantation and clear-cutting forestland of Mongolian oak+black birch forest, were selected as the research object. Field sampling ware carried out in April and July,2011. And the soil macrofauna were picked up by hand in the field, while the Soil meso-microfauna were separated by method of Tullgren. A total of49groups,6295individuals were collected, belonging to4phyla,25orders,38families. Among the groups, dominant groups were Ants, Oribatida, Gamasida and Isotomidae, which accounted for69.82%in all soil fauna. And there were11common groups included Scarabaeidae larvae, Lumbricidae, Geophilomorpha, Lithobiomorpha, Diptera larvae, Araneae, Curculionidae larvae, Nematode, Enchytraeidae, entomobriyidae and Actinedida, which accounted for25.12%in all soil faunas. Dominant groups and common groups, which accounted for94.94%, was the main components of soil fauna of Zuojia Nature Reserve. They distributed in every habitat and showed better adaptability than rare groups. The rest of groups, which accounted for5.06%, were rare group.Cutting can cause certain effect to soil fauna. In the horizontal distribution,35groups,2846individuals, were collected in clear-cutting forestland, while42groups,3449individuals, were collected in unclear-cutting forestland. Individual number or group number of soil fauna in clear-cutting forestland was less than that of unclear-cutting forestland. In another word, clear-cutting forestland was worse to survival of soil fauna than unclear-cutting forestland. In vertical distribution, soil fauna in different habitats showed the rule of surface-aggregation, which means that number of soil fauna decreased with the increasing the depth of soil layer, because soil organic matter and total nitrogen content of surface soil were more suitable for soil fauna.Using the Sprensen similarity index(s) to compare soil fauna’s similar degree, the results show that the similarity indexes among macro-soil fauna and micro-soil fauna in all forestlands were very high (ranks of very similar or medium similar). Compared to the diversity index, richness index and evenness index of unclear-cutting forestland, the three indexes of clear-cutting forestland were lower. This is due to be that clear-cutting forestland was disturbed serious, so that the environment changed. We use the method of person correlation index to explain the relationship of soil fauna and their environment. Results showed that pH value, soil total nitrogen and organic matter, especially the pH value and total nitrogen, significantly related with soil fauna. However, the total phosphorus and soil water content showed no significantly relationship with soil fauna.