Vegetation restoration of gangue wastelands with particular reference to climax communities

With the Sanlidong gangue wastelands as the subject, the basic status of vegetation restoration was investigated through sample plot survey. Gangue efflorescence and vegetation were conducted based on sampling so as to research and analyze the contents of nutrients and toxic elements between gangue efflorescence and vegetation. The reference vegetation was eastablished and the climax communities could be reconstructed in combination with the corresponding site types. Main research results are listed as follows: (1)With the increasing years of gangue discharge suspension, the categories of woody plants also increased with rising frequency, coverage rate and biomass. (2)The pH value of gangue efflorescence was almost the same with that of the loess, with the increase of succession years, there were a tendency of gradual increase in the contents of water, total S, hydrolytic N, available P and organic matter, while the contents of total N and available K gradually decreased. The contents of Hg, Cu, As, Cr, Pb and Zn all tended to decrease, but the contents of Hg, Zn were still higher than the background value. (3) Ailanthus altissima has strong capacity of absorbing Cu, Zn element. Setaria viridis and capsella bursapastrois have strong capacity of absorbing Zn, Cr element. Robinia pseudoacacia´s capacity of absorbing Cu, Zn and As element were also greater than those of other plants. (4) Ailanthus altissima and Robinia pseudoacacia were preferred as the pioneer plants in the reconstruction of artificial vegetation community and priority shall be given to the community mode of Robinia pseudoacaciatimesPpophae rhamnoidestimesCapsella bursapastrois, Robinia pseudoacaciatimesPpophae rhamnoidestimesSetaria viridis, Ailanthus altissimatimesPpophae rhamnoidestimesSetaria viridis.