This paper focuses on the research into the vegetation of three iron mine tailing wastelands of Shilu Mining Area (in Changjiang county, Hainan) in different periods. According to the data derived from this on-the-spot investigation into the wastelands, the author of the paper calculated the important value of the plant species, the index of diversity of the plant species as well as the evenness of the plant species.
The findings showed that in each wasteland, the types of plant species on the whole were not many and the composition between the plant communities was relatively different. In No.1 waste-land, which was deserted two decades ago, there were 44 types of native plant species, among which Gramineae family was the most dominant while Leguminosae and Cyperaceae families are less dominant, especially the species like Phragmites karka and Paspalum commersonii of Gramineae, and Typhaceae angustifolia of Cyperaceae were flourishing and more adaptable to the habitat. In No.2 wasteland, which was abandoned two years ago, 21 types of native plant species had been found, among which the most adaptable were Panicum repens, Saccharum arundinaceum and Miscanthus sinensis that belonged to Gramineae family. The vegetation of No. 3 tailing wasteland, which is still being mined now, was much worse than that of No.1 and No.2 wastelands. Because of its poor habitat, only three species could survive, which were Pyllosacys karka, Sesbaniacannabina and Miscanthus sinensis.
The analysis of the findings had indicated that the plant community structures of the three mine wastelands were obviously different in succession sequence, single species dominance lowering from No.3 to No.1 and species diversity indexes increasing from No. 3 to No. 1. This phenomenon demonstrated that the succession trends changing from simple plant communities composed by few pioneer species to complex and stable communities, and plant community structures become more complex with the succession going on. Besides, the analysis of vegetation of No.1 wasteland showed that even in the same digging, different water contents and different physical and chemical characters might influence the plant ecesis and community composition at different levels. For this part, a further study is necessary.