Abstract: Mining changes the community structure and composition of grassland. We conducted an experiment to study the variability of aboveground biomass in grassland communities and the compensatory effect among species. We took Stipa grandis steppe around Baiyinhua mining area in Inner Mongolia as the research object,and analyzed community composition,the variability of aboveground biomass at different organization levels (species,functional groups and communities) and the compensatory effect among species/functional groups. We found that the common species were Stipa grandis,Carex korshinskyi,Cleistogenes squarrosa,Leymus chinensis,Agropyron cristatum and Anemarrhena asphodeloides， and the cumulative relative importance value of the six species was 79.63%. Secondly,at the species and functional group levels,the variability decreased with the increase of aboveground biomass (R²=0.24,P<0.01;R²=0.63,P<0.05). In addition,with the increase of organizational level,the rank of the variability levels was population (587.13%) > functional groups (237.94%) > community (44.65%). Moreover,the compensatory effect mainly existed between dominant species and dominant or non-dominant species,between dominant functional groups and dominant or non-dominant functional groups,and the possibility of compensatory effect between non-dominant species and non-dominant species and between non-dominant functional group and non-dominant functional group was small. In the process of mining,both economic and ecological aspects should be taken into account in order to keep the grassland community stable.

Key words: Mining, Grassland, Variability, Compensatory effect

摘要： 开矿为人类创造物质财富的同时，会对群落结构与组成产生一定的影响。为研究草地群落中地上生物量的变异性及物种之间的互补效应，本研究以内蒙古白音华矿区周边大针茅（Stipa grandis）典型草原为研究对象，分析了草地群落组成及物种、功能群和群落等不同层次地上生物量的变异性及其互补效应。结果表明：群落主要物种为大针茅、黄囊苔草（Carex korshinskyi）、糙隐子草（Cleistogenes squarrosa）、羊草（Leymus chinensis）、冰草（Agropyron cristatum）和知母（Anemarrhena asphodeloides），6种植物累计相对重要值为79.6%。在物种及功能群水平，随着地上生物量的增加，其变异性显著降低。随着组织水平增加，变异性的顺序依次为种群（587.1%）>功能群（237.9%）>群落（44.7%）。互补效应主要发生在优势种-优势种或非优势种间、优势功能群-优势或非优势功能群之间，非优势种-非优势种或非优势功能群-非优势功能群之间发生互补效应可能性较小。在开矿过程中，应同时兼顾经济与生态两方面，以保持草地群落稳定。

关键词: 开矿, 草原, 变异性, 互补效应