Abstract:

Spoils accumulated in the process of coal mining are usually deficient in plant nutrients. Fertilization is an effective means to improve the soil physical and chemical conditions and promote the revegetation of coal mine spoils. This research studied the establishment of artificial grassland on coal mine spoils in Jiangcang alpine mining area， and explored the appropriate fertilization level for ecosystem restoration in this locality. Treatments imposed included light， medium， and heavy fertilizer application， no fertilization within the first year （CK）， and no fertilization within 5 years， and the grassland community structure， plant growth and soil properties were characterized under the different fertilizer regimes. Correlations between plant and soil parameters were evaluated. The main results were as follows： There were no significant differences in species composition among the different fertilizer application levels， but the community diversity and evenness indexes decreased significantly （P<0.05） under heavy fertilization， and the community richness and diversity index decreased significantly （P<0.05） compared with CK after 5 years without fertilization. Both excessive fertilization and a period of some years without fertilization were detrimental to the stability of the grassland community. Compared with CK， light fertilization， moderate fertilization and heavy fertilization increased the vegetation cover， plant density， height and above-ground biomass of the established artificial grassland to varying degrees， and the results under moderate fertilization were superior to those of other treatments. Compared with CK， heavy fertilization significantly increased soil available nitrogen， total phosphorus and available phosphorus content （P<0.05）. Moderate fertilization was more conducive to the accumulation of soil organic matter compared with other treatments. With the exception of soil pH value， plant growth parameters were positively correlated with soil properties. In particular， there was a significant positive correlation between plant growth parameters and soil total potassium and soil organic matter content （P<0.01）. In summary， an appropriate level of fertilization improved vegetation growth and soil properties of artificial grassland established on coal mine spoils. However， both too much fertilizer application and no fertilizer application were detrimental to the stability of the artificial grassland ecosystem in Jiangcang mining region.

Key words: fertilization level, alpine mining area, coal mine spoils, vegetation restoration, soil restoration