Abstract: To explore soil improvement under different restoration modes of open-pit mine dumps, we analyzed the characteristias of soil nutrient contents and enzyme activities under different vegetation restoration modes (Robinia pseudoacaciaforest, elm forest, mixed forest, shrubland, and abandoned grassland) in Haizhou openpit mine of Fuxin. The results showed that soil nutrient content in all vegetation restoration modes decreased with soil depth, with obvious surface aggregation. The activities of sucrase, catalase, and urease in all the five vegetation restoration modes peaked in the 0-10 cm soil layer, which was significantly different from the other soil layers. Soil protease activities peaked in the 0-30 cm soil layer. Soil nutrient contents were significantly correlated with soil enzyme activity. The results of principal component analysis showed that the principal component comprehensive scores of Robinia pseudoacacia forest, elm forest, mixed forest, shrubland and abandoned grassland were 2.94, 1.68, 4.44, -2.66, and -6.39, respectively. The overall performance of vegetation restoration effect was mixed forest > Robinia pseudoacacia forest > elm forest > shrubland > abandoned grassland. The shallow soil layer had the best restoration effect, with the effect gradually decreasing with soil depth. The mixed forest could be used as the main revegetation mode in this dump site.

Key words: dump site, vegetation restoration, soil nutrient, enzyme activity, comprehensive evaluation.