Wild Herbs Invasion Characteristics In Reclaimed Land Of Large Opencast Mine Within Loess Area

Biodiversity is the basis of the survival and development of human society, and so is ecosystem stability. Many large, extra large coalfields lie in loess area. Large areas of land was occupied and damaged because of large-scale coal mining, especially open-pit mining. Therefore, the original ecosystem was destroyed completely, and biodiversity was sharp reduced. Land reclamation has made a significant contribution to adding cultivated lands and protecting the development, however, biodiversity conservation has not been taken into account in the entire process of mining at present, so that eco-environmental benefits after the land reclamation has not been adequately reflected. As a result, study on land reclamation and biodiversity conservation of large opencast mine in loess area is an urgent need to carry out.The wild plants invasion plays a vital role in the biodiversity of the complex ecosystem after ecological reconstruction. This paper, based on a case study on the dump of AnTaiBao surface coal mine in Pingshuo mining area in Shanxi province, analyzed and researched wild herbs invasion status of large opencast mine area and influencing factors under different site conditions, using large quadrants survey methods. Through the analysis of the wild herbs invasion characteristics, focus and direction is explicit to enhance and protect the biodiversity of reclaimed land, in order to provide the scientific references for land reclamation and ecological reconstruction of large opencast mine in loess area.The conclusions as follows:First, after10years of land reclamation, there are122species wild herbs in reclaimed land of ATB surface coal mine, belonging to27families and82genera, including115invasive herbs, and herbs planted in beginning period are in sharp degradation. Compositae, Gramineae and Leguminosae played the largest role in the process of ecological reconstruction and rehabilitation in reclaimed land of ATB surface coal mine. These three subjects constitute the largest proportion in the plant communities, and affect community succession also. Perennials dominate from the structure of plant life form, so ecosystem tends to stabilize.Second, biological invasion is a complex process. In the later stages of land reclamation, time has little effect on wild herbs invasion of each plots, reclamation mode is the main reason for the discrepancy. Herbaceous plant species richness is impacted by the species diversity. The crown density is the lower, the degree of wild herbs invasion is the higher. Wild herb invasion degrees of trees mixed is lower than tree and shrub mixed, and higher than trees.Third, Herbaceous plants’growth is influenced by the micro environment to a certain extent. Herbaceous invasive species are more diverse and distribute more evenly on the platform, but less diverse and distribute less evenly in the slopes. Biodiversity is higher in the low elevation areas, and lower in the high altitudes.