Plant Community Character And Its Soil Effect In Rare Earth Elements Mining Area Of Fujian Province, South China

With the great development of society and economy, amounts of rare earth elements (REEs) are consumed increasing while the destruction of resources and environment is becoming more and more serious. Consequently, those situations have produced a serial of severe soil erosion after destructing the surface vegetation, which has imposed tremendous degeneration of the ecological system. Ecological restoration and reconstruction of damaged ecosystem has become more and more concerned issue nowadays. Therefore, how to restore the vegetation of south rare earth mining area and how to form the self-sustaining, sustainable ecological system are becoming the most important subject in the process of ecological construction, which would improve the eco-environment and promote economy sustainable development.Four rare earth elements mining areas including three exploration areas and one non-exploration area on rare earth elements mining area are selected in Changting County, Fujian Province. The plant diversity, REEs, physics and chemistry character of soil, nitrogen content of various forms of typical plants both in the rhizosphere soil and bulk soil have been studied. The results showed as follows:(1)Patrick richness index of herb layer, Alatalo homogeneity index and Shannon-Wiener diversity index of shrub layer were becoming more higher gradually with increasing management time, except for Alatalo homogeneity index. Alatalo homogeneity index of shrub layer among four research areas were larger than those of shrub layer. The height and covering degree of dicranopteris dichotoma rose slowly then increased rapidly with the growth of management time gradually, and then reached 85cm and 95% respectively. (2)The order of REEs content was Xiakeng (507.37mg/kg)>Niushitang (219.1 lmg/kg)>Sanzhoutongba (94.91mg/kg)>Longjing (33.07mg/kg), and ∑L/∑H was much less than 1. The order of soil mechanical composition in three rare earth elements mining areas was sand>silt>clay. The organic of upper horizons among four areas is significant correlation, while TN, TK and AK of the deeper layer were not insignificant. (3)The nitrogen content of various forms, soil organic carbon content and soil pH value were analysed both in the rhizosphere soil and bulk soil. Total nitrogen, ammonium and nitrate in rhizosphere soil were 79.7%,34.2% and 30.7% higher than those of the bulk soil. Soil organic carbon in the rhizosphere was 164.9% higher and soil pH value was lower by 0.12 units than the average of bulk soil. Except for pH value, the rhizosphere soil was significant different with bulk soil in content of soil total nitrogen, nitrate and organic carbon contents. The content of total nitrogen, ammonium, nitrate and organic carbon in the rhizosphere soil are more than those of the bulk soil. The soil pH in Dicranopteris dichotoma, Liquidambar formosanas rhizosphere soil are higher than those of the bulk soil, and the soil pH in Paspalum wetsfeteini, Schima superba’s rhizosphere soil are lower than those of the bulk soil. Soil total nitrogen is positive correlated with organic carbon both in the rhizosphere soil and the bulk soil. There is no significant correlation between soil total nitrogen and ammonium in rhizosphere soil and the bulk soil, so is the soil total nitrogen and nitrate.