Characteristics Of The Soil Fauna During The Ecological Restoration Of The Disused Iron Mining Land In Anshan, Liaoning Province

Anshan city, the"steel capital", is the largest iron and steel industrial base and plays an extremely important role in China's national economic development. As the most important iron producing base, Anshan iron ore has been explored for more than 80 years, which causing some inevitable impacts on the ecological environment. For example, the occupied and damaged mining pits; the stripped topsoil, which is causing vegetation damage and soil erosion; undermined balance of the stratum during the mining and engineer building. Thus, it is so closely related between the mining city's development and the mine reclamation that the mining ecological restoration of Anshan is imperative for a continuable development strategy.Whether the disused mining land can be restored to the original ecosystem or can be rebuilded a new harmony ecosystem has been focused by many scholars in recent years. In the process of renewing the disused mining ecological system, soil animals are indispensable part of the ecosystem, and are one of the biological indicators of a stable ecological system, and can be used as biological indicators of environment monitoring and evaluation. Some experts have done many works on the restoration of the ecological restoration, among these; the researches on the mine land reclamation are more than those of the soil fauna. In this paper, the different bands of Dagushan disused mining area and Qidashan disused mining area are selected for the research of soil fauna. The following are the research achievements:1. After continuous investigation of Dagushan abandoned land, we find, in the different stages of the five sections, the large soil animals were attached to 11 categories, 4 programs in 2 phylums, and there are 2 predominant groups, 1 common group, and 9 rare groups. This shows that the soil animals'structure in Dagushan abandoned iron field is simple, and the composition of the community is the wide-spread species, which is similar with the species of Northeast: Formicidae, Spiders, Staphylinidae, Coleoptera, and different from Xiaolongmen forest soil animals of Beijing: gastropods are the most, Arachnida fewer, Coleoptera fewest, and Formicidae are almost 0.2. In the 8 different manual forests of Daqishan iron disused land, there are 13 categories, 10 projects, 4 programs and 1 phylum. The dominant groups are Formicidae, Coleoptera (including larvae), the Centipede, and Araneid(four categories), the common groups are Hemiptera, Lepidoptera (including larvae), Diptera, Hymenoptera, Isoptera,Chilopoda,Chilopoda,Orthoptera, the rare groups are Orthoptera, Symphyla。The total component individuals in dominant groups and common groups are 99%, which constitute the principal part of the soil fauna. It reflects that the soil fauna system is still at its preliminary stage, and their ecosystem adaptability is weak.3. Formicidae is the main soil animal in the Dagushan and Qidashan iron mining abandoned lands, it is the same with the dominant groups of Yuelu Mountain and similar with the wide-spread species of Formicidae, Araneae, Diptera larvae, Coleoptera in Northeast, but different with Tianmushan , Hengshan, Xiaolongshan, Xiaohenganling etc. The plentiful Formicidae showes that the natural ecosystem of Anshan Iron abandoned area is drier, and the changing advantages of Formicidae indicate ecological environment in the abandoned land is changing.4. There are some differences in the ecological structure of Anshan iron disused land. The disused time can influence the ecosystem components, that is, the longer the land disused, the better the ecosystem recovered, except the inappropriate human disturbance, which may have to restore the natural structure and function of generating new damage restoration of the ecological environment impact. In addition, the spatial differentiation of soil fauna diversity, for example, artificial fertilizer intervention can increase the soil fauna diversity, but does not good on soil fauna stability. For example, Although the vegetation appears good after being renovated several times(Dagushan pit of the stage 1), the ecological development of the soil fauna is similar with the new abandoned iron land, it indicats that the soil stability is not very good.5. The soil fauna investigation of the 5 profiles in Dagushan disused land and 8 profiles in Qidashan disused land shows that, the large soil animal diversity and richness index, evenness index was positively correlated, and was negatively correlated with the advantages index, and there are not directly relations with the numbers of individuals. In different habitats, poplar and acacia forests, soil fauna increases along with the growth of age, and its richness, diversity index grow with the growth of the trees age. But the individual soil fauna are not reflected in the relevant information.6. The vertical distribution of the soil animals in the different soil habitats of Anshan iron disused land is: the animal taxa diversity and individuals number reduce with the increase of the depth, which indicats that the taxa number and individual number of soil fauna in different habitats are apparent in the surface layer. Moreover, the soil fauna diversities in Anshan iron abandonded mining fields are different but a little similar because of the different habitat in different forest types.It reveals during the research: As a biological index of a special and stable habitat, the research of longterm dynamic changes and orientation, and the bulding of biological indicators database of the soil fauna will be good indicators in the mining ecosystem recovery. So, this thesis is of great practical significance in the rehabitation of disused mining lands.