Vegetation Ecology Of Abandoned Copper Mine Lands On Zhongtiao Mountain Areas,Shanxi

The key of ecological restoration of abandoned mining lands is revegetation restoration. As the restoration process of spontaneous revegetation is very slow, it must adopt the positive artificial restoration measures to improve plant community seccession. The spontaneous revegetation of abandoned copper mining lands on Zhongtiaoshan Nonferrous Metal Group in Yuanqu, Shanxi were studied by using a space-for-time substitution method to collect vegetation data simultaneously at different succession stages, moreover, and the community composition, the structure, the spatial distribution, the succession tendency of spontaneous revegetation, the change of species richness, evenness and overall diversity at different restoration stages on the abandoned copper mining areas were analyzed by quantitative ecological method including TWINSPAN, DCA, diversity indices, interspecific relationship, niche breadth and overlapping. Furthermore, the revegetation mode and strategies in this areas were discussed, which will be of great benefit for Shanxi and its neighboring areas. The mainly studied and corresponding research are as followings:(1) There were recorded88species of vascular plants in the filed totally, including74species of herbaceous plants,4species of shrubs,10species of tree, and occupied84.09%,4.55%,11.36%respectively. Based on the floristic regionalization of China, these species belong to36families74genera and were divided into11distribution types, three subtypes. The temperate zone was dominant, including38genera, accounting for51.35%. Among which the plant species of temperate zone had49kinds, aoccounted for the total was55.68%, and it reflected the environmental characteristics and fully shows the characteristics of the region's temperate zone.(2)81samples were divided into eight associations by TWINSPAN. They were respectively:ⅠAssoc. Ailanthus altissima-Setaria viridis+Artemisia lavandulaefolia;Ⅱ Assoc. Setaria viridis+Amaranthus retroflexus;Ⅲ Assoc. Setaria viridis+Artemisia annua;Ⅳ Assoc. Robinia Pseudoacaia-Artemisia sacrorum+Artemisia lavandulaefolia;Ⅴ Assoc. Ailanthus altissima+Robinia Pseudoacaia-Artemisia sacrorum+Setaria viridis; Ⅵ Assoc. Artemisia lavandulaefolia+Chrysopogon aciculatus; Ⅶ Assoc. Artemisia lavandulaefolia+Artemisia anethifolia;Ⅷ Assoc. Artemisia annua+Macleaya cordata. Each Association had different species composition, so their structure and function were different too. In two-dimensional DCA diagram of the samples amd species, every axes represented the different meanings in Figure. It showed environment factors that affect the community stability, such as waste time, altitude, soil moisture, fertility and so on. The combination of two methods could be better to reflect the characteristics of vegetation quantity.(3) The vegetation succession of natural recovery on the mining abandoned lands were investigated by using Shannon-Wiener index and Petraitis's niche-specific overlaping and general overlapping index. The results showed:the dominant species has a wide niche breadth in the different associations. It shows that the bigger the adaptability of these species to environmental ecological factors is, the wider the distribution range is and the stronger the ability of using the environmental resources is. The greater the niche overlap of the dominant sapecies is, the larger the ecological similarity between populations, the stronger the commonality or similarity is in ability to adapt to the environment and use of resources, the fiercer the interspecies competition is. However, these species in the associations which has the wide niche breadth may not have the higher niche overlap.It indicates that these species can share the environmental resources and improve the structure and function of associations and maintain the ecological balance of associations to a certain extent.(4)χ2-test with2×2contingency table and Jaccard indices were used to analyze the interspecific relationship of13dominant species of community. Pearson's correlation coefficient and Spearman's rank correlation coefficient were also applied to calculate correlations between species. The results indicted that species with positive association have similar biological characteristics and demand similar habitats, and the relationships among species-pairs are of significant difference in different communities and succession stages. The significant species-pairs from χ2-test is lower than that from the Spearman rank correlation test and Pearson test, and the Spearman rank correlation test is better than Pearson test.(5) The species composition, community structure and the degree of stability analyzed by using Simpson diversity index, Shannon-Wiener diversity index, Patrick richness index, Pielou evenness index and Alatalo evenness index respectively. The result shows that the greater the diversity index, the greater its richness, the more perfect the structure and function in community. The diversification of evenness index wasn't big in the8communities, indicating that plant species adapted to the current environmental conditions, the competition was not very intense each community and these communities were stable. Based on the analysis of quantitative ecology methods, we have got the law of vegetation succession on the copper mine abandoned lands:herb communities→shrubs→forest.(6) To speed up the process of vegetation restoration on the mining abandoned lands, a series of techniques and measurments through the human intervention should be taking, and the pioneer species that adapt to local ecological environment were choosn. Through the investigation, the vegetation restoration model was introduced, that is the combined ecosystems by the tree, shrub and grass. In the model we have selected the pioneer species, in cluding Setaria viridis, Artemisia gmelinii, cordata, Robinia pseudoacacia and Ailanthus altissima. Finally some several criteria of vegetation restoration were discussed.