Effects Of Heavy Metal Pollution On Ecological Environment Of Lawu Mine In Central Tibet

Mine as a base for energy and raw materials for energy production plays a critical role. But in the actual production process, the distribution of mineral resources has a strong regional, and many mineral resources buried deeper underground, its exploitation will inevitably cause damage to the ecology or land occupied, coupled with the mining process emissions from a variety of minerals with toxic waste will gradually form a wasteland, a continuing source of pollution. As the basis for human survival, the land is one of the essential natural resources, a large number of abandoned land pollution not only cause serious damage to land resources, but also a great impact on the mine geological environment, and ultimately lead to resource damage, geological disasters, causing irreparable damage on the production of human life and the natural environment. In this article the author in order to restore the ecology theory as a research idea to the natural recovery mainly to artificially restore the principle of soil conditions on the copper area of the house pull of China's central Tibet, biomass, biodiversity, species as well as The mining area productivity, such as in-depth, comprehensive study, the following conclusions:(1) pull the house mining wasteland matrix mainly of gravel and stone, accounting for79.8to91.8%; sand the following fines content rarely, accounting for8.2to20.2%, therefore, abandoned mining area ventilation permeable and difficult water soil temperature changes, the adsorption of available nutrient poor, ensure fertility, is one of the important factors to cause the plants to settle difficulties. Mine ecological restoration process should be paid great attention to the improvement of soil physical properties.(2) mining of different soil types Nutrient characteristics analysis showed that the mining area sample matrix pH value range of6.03to7.331.2to4.1%organic matter content, soil total N in0.04～6.81g/kg, total P content of0.65～6.81g/kg;3.45-38.00times the original soil content of Cu, Zn12.05-24.49times the original land, Pb and Cd were2.57-19.46and2.45-45.86times; effective content is5.6636.73,18.46to30.05,13.48to44.98and2.06to12.24times, compared with the national heavy metal elements, the average is significantly higher. Mines in mining after the destruction of rainwater falls on mineral nutrition. Mine soil available K, organic matter and available P, N, is a serious lack. Fertility level of the overall mining wasteland, and fertilizer, low water retention capacity and subject of Cd, Cu and Zn in severe compound pollution. Therefore, the growth of vegetation is extremely unfavorable. Repair of organic matter and other nutrients in the repair process of land use, it should be fully taken into account in order to improve the soil structure, and fundamentally improve the soil self-coordination.(3) pull the housing within the mining area of the soil are subject to the Zn, Cu, Cd, Pb and other heavy metals polluted to varying degrees, gradually weakened from the center area200meters away; relative to the control soil, the original soil microbial biomass, enzyme activity were greatly inhibited the soil qCO2and basal respiration were under great stimulus, obtained by multiple regression analysis, under the combined pollution of heavy-metal, the sudden microbial activity to be greatly affected. Index analysis of the microbial activity can reveal the mine soil heavy metals in the actual situation of the pollution, can be used as an important basis on mine soil quality assessment and classification of pull housing. By principal component analysis and linear correlation analysis showed that the heavy metal content and the quantity and activity of microbial communities was a significant correlation, the principal component of the parameters of heavy metal (H-to-PC) and soil microbial parameters, principal component (M-PC1) has The strongest correlation, indicating that the first principal component of the soil microbial parameters (M-PC1) can effectively reflect the situation of Tibet in the mining area of heavy metal pollution.(4) soil heavy metals and bacteria, actinomycetes showed some negative correlation between the description of Heavy Metal pollution significantly reduced the size of the microbial flora. The study also showed that bacteria, actinomycetes and fungi, the number of the coefficient of variation (CV%) were1.56,1.97,0.29, three micro-organisms to heavy metal stress sensitivity is not the same, namely actinomycetes> bacteria> fungi. Mining areas of different degree of pollution of soil bacteria, actinomycetes, soil heavy metal contamination of soil microbial bacteria, actinomycetes bacteria, ammonification bacteria, nitrifying bacteria and fiber decomposition of the number of bacteria and microbial biomass C content, basal respiration The and qCO2.(5) pull the housing mine the original ecology of grassland plant diversity and richness indices will be within a certain range with elevation changes and changes in the highest when the altitude of4660m, and then decreases. July and August, richness, diversity index, June, September richness and diversity indices. Showing the distribution of the original ecology of grassland plant species in different altitude ranges in the same growing season and to form there are some differences, even in the same altitude, the species due to the different seasons also showed different growth and change. In addition, the study indicated that the competition for resources in the different species of vegetation for water and light and heat, followed by soil nutrients, particles, and landscapes. Moisture and temperature are the main factors affecting changes in plant niche. The competition between the species in different communities, there are also a big difference, even if it is the same kind of plants sometimes form different competitive relationship. This difference is more stable landscape, soil conditions, temperature, niche, and yearly changes in precipitation in common cause. Therefore, in the process of mine ecological restoration species, it should be distributed according to the season of the original ecology of grassland herbs characteristics, population niche characteristics and altitude distribution characteristics of species combinations of different options, in order to achieve a variety of mines ecological restoration, promote the natural reservoir of the mining vegetation, and soil conservation function and maintain nutrients, in order to build a diversified stable and efficient community, thereby contributing to the benign and stability of ecosystem restoration.(6) soil organic matter content is very significant impact on plant productivity. The pilot study found that, through a mixture of organic soil can greatly enhance the Elymus nutans grass seed germination speed and improve germination probability of topsoil organic soil content reaches half its germination rate approaching the maximum; environmental conditions in the highlands, the nutans Elymus biomass formation and the temperature and precipitation in the seasonal changes have a clear relationship and geographical characteristics. Its peak production period is usually in early August. Prior to this pattern of growth in line with the logistic growth equation. Mine the actual recovery process, in addition to organic manure, make full use of mine water heat relations, improve the productivity of the dominant species, and promote the role of the dominant species on the mine ecological recovery.(7) can be obtained through the analysis of test results:mining on the plateau to take ecological restoration strategy should be fully integrated with the biological and engineering measures, select the biological recovery of species measures, we should pay full attention to the seasonal characteristics of the species, niche distribution characteristics natural conditions of the mining area, select grew faster, more developed root system, drought, cold resistant, the dominant species of choice for ecological restoration as mine. And take a series of supplementary means of fertilization, and new soil, to accelerate the speed of the mines ecological restoration.Overall, the mine ecological recovery is not just the pursuit of the fast recovery of ecological environment in mining, but should be starting from the overall, to mine the stability of ecosystems, biodiversity and ecological restoration of mine the benefits of goal of mine as a whole ecosystem considering the construction project.(8) From analysising and researching meteorological factor of mine, physical and chemical properties of different sectional soil(stromal), mature planting technology, the test of planting technology in the mine, and the limiting factor of plants growing, we can get the following achievements:about4modes of seeding technology, including thetechnological restoration of the failure surface of road construction, the restoration of landslide of slag accumulation, the restoration of the landslide which road constuction formed, and the restoration of the tailings, and the mixed seeding(50:35:15) of the Elymus, the Sibiricus, the Brassica juncea which is auxiliary plant,which can create the appropriate surfacial microenvironment of water and temperature of plant colonization. Forever, fertilizing the foliar of pioneer plant can accumulate carbohydrates and sugars and strengthen its overwintering ability safely. In addition, the mixed seeding(95:5) of seed and grain of aquasorb,the recvering of film and shade network, the moisture and the warming can promote seed germination and rapid growth of seedling, as well as establish the crucial technology and thetechnology system of ecological restoration of similar ecological envirnment in mining.