Study On The Characteristics Of Natural Restoration In Plants Growing On Mine Waste Platform

Based on a field survey and analysis on habitats and vegetation and soil of Sha Ba Pb/Zn mined wastelands in Hui Xian of Gan Su province. This paper systematically researched the number and species and genera of natural colonized plants as well as the characteristics of habitats and vegetation on the Sha Ba Pb/Zn mined wastelands. Revealing the process of habitats change and vegetation community succession under the condition of natural revegetation.Researching distribution of concentrations of Pb,Zn,Cd,Cu in soil and root,stem and leaves of Artemisia vulgaris on the Sha Ba Pb/Zn mined wastelands. The main results are as follows:(1) The results showed that 40 species belonging to 17 families and 27 genera of higher plants were found on the Sha Ba Pb/Zn mined wastelands, including 2 dominant families:Compositae and Gramineae is 20% and 15% respectively of the total number of species, Leguminosae was also found growing on the Sha Ba Pb/Zn mined wastelands. Growing of Lagerstroemia indica of Rosaceae and Ailanthus altissima of Simaroubaceae indicated natural colonized plants has formed distribution of vertical structure, embryonic form of early vegetation is Grass-Shrubs-Tree ,stable communities of grass were found on 11a wasteland.(2)Artemisia vulgaris as a role of pioneer and constructive species on vegetation composition was found, the highest of its important values of dominance speices in the total species of wastelands, Respectively 0.254,0.168 and 0.318 on 3a,6a and 11a wastelands.(3) Rubus parvifolius and Cynodon dactyllon of clonal plants are more adaptive to environment and more important to restoration of vegetation than other plants,because of it's outstanding performance for propagation and ability to conquer habitats. Supplementary of habitat countermeasures is dormant strategy of Digitaria sanguinal is and Puccinellia chinampoensis.(4) Chemical analysis of the total concentration of heavy metals in mined wasteland indicated: The highest concentration of Zn=13420mg/kg, Pb=6298mg/kg, Cu=108.49 mg/kg,Cd=2.965mg/kg on the Sha Ba Pb/Zn mined wastelands. Comparison of CK for the background value, the average concentration of Zn,Pb,Cu,Cd on the Sha Ba Pb/Zn mined wastelands for its 36.06,30.69,2.178 and 4.474 times.(5) Artemisia vulgaris has absorbed heavy metals in distribution of its body is leaves>root>stem, the concentration of heavy metals in shoot is higher than root of this species. Artemisia vulgaris can absorb and accumulate heavy metals, respectively but it was also confirmed that it is not the heavy metals of Cu, Zn, Pb, Cd superaccumulator,the strongest bioconcentration of ability that Artemisia vulgaris is able to absorb the heavy metals of Cu, the weakest ability of Artemisia vulgaris is able to transfer the heavy metals of Pb.(6) The Pb of weak retention rate is 36.5% in root of Artemisia vulgaris, but it is not retention rate for Cu, Cd, Zn, respectively. Artemisia vulgaris can absorb different heavy metals of Cu, Zn, Pb, Cd, and it has the characteristics of resistance to the heavy metals.