贺兰山露天煤矿生态修复前后植物群落差异及地境结构研究

Plant Community Difference and Land Structure before and after Ecological Restoration in Helan Mountain Open-pit Coal Mine

为探究贺兰山露天煤矿生态修复后植被恢复情况,依据生态地质学的相关理论和方法,通过野外植物群落特征和植物根群结构调查,以及植被地下生境土壤肥分养分取样与测试,对背景区与恢复区植物群落结构和物种多样性差异进行了对比分析,确定了不同植物群落的地下生境范围,并进一步探究了影响植被恢复的土壤因子。结果表明:(1)贺兰山自然保护区主要存在6种植物群落,背景区为针茅群落和白莲蒿群落,修复区在这两种群落之外新增了华北米蒿群落、寸草苔群落、火炬树群落和香蒲群落;(2)相较于背景区,修复区的针茅群落和白莲蒿群落的植物种类更丰富,且优势种的优势度较低,个体分布较为均匀,表明修复区针茅群落和白莲蒿群落存在向背景区演化的趋势;(3)地表以下0~20 cm土壤深度范围内是研究区植物群落主要的植物根系功能区,在此范围内修复区土壤中有机碳含量和全氮含量远高于背景区,而修复区土壤中全磷含量低于背景区,土壤中磷成为制约植被恢复的主要元素,并且在植物根系功能区范围内,部分矿区仍存在土壤酸性污染,影响了植被生长。本研究结果可为我国西北干旱、半干旱地区矿山生态修复的覆土厚度、植物类型、土壤肥分等的选择提供理论依据和技术参数。

To explore Helan Mountain open-pit coal mine after the ecological restoration of vegetation recovery, on the basis of relevant theories and methods of the ecological geology, through field investigation of the plant community characteristics and the plant root group structure, sampling and testing of the underground habitat and vegetation maps of soil nutrients, this paper comparatively analyzes the background area and recovery area differences in plant community structure and diversity, determines the scope of the different plant community of underground habitat.Furthermore, the soil factors affecting vegetation restoration is further explored.The results are as follows:(1)There are mainly six plant communities in Helan Mountain Nature Reserve, Stipa spp.community and Artemisia annua community in the background area.Artemisia artemisiae frabectifolia community, Lepidophora artemisifolia community, Artemisia artemisifolia community and Cattailpha community are added in the restoration area outside of these two communities.(2)Compared with the background area, the communities of Stipa staphylla and Argylla lanceolataare more abundant in plant species, and the dominant species are lower in the restoration area, and the individual distribution is more average, indicating that the communities of Stipa staphylla and Argylla lanceolata have a trend of evolution to the back area.(3)0~20 cm is the main plant root functional area of the plant community in the study area.Within this range, the content of soil C and N in the restoration area is much higher than that in the background area, while the content of soil P lower than that in the background area, which becomes the main element restricting vegetation restoration.Moreover, in the range of plant root functional areas, there is still soil acid pollution, which affects vegetation restoration.This study can provide theoretical basis and technical parameters for the selection of covering soil thickness, plant type, soil fertilizer content and so on for mine ecological restoration in the arid and semi-arid area of Northwest China.