典型干旱半干旱草原矿区生态累积效应

Ecological cumulative effect of mining area in typical arid and semi-arid grassland

位于黄河流域中上游的内蒙古干旱半干旱草原区,是我国"两屏三带"生态安全屏障区,也是大型煤炭基地和煤电基地的分布区。由煤炭资源开采造成的土地退化、地下水位下降、生物多样性减少等生态问题,经过长期累积和空间外扩,对矿区及周边地区生态产生严重负面影响。针对这一区域生态累积效应的研究已经引起了国家和社会的关注。已有研究主要聚焦干旱半干旱草原矿区某一生态要素、某一时间段的生态效应分析,而煤矿发展具有生命周期和复杂的能量物质流动。为此,(1)阐述了国内外干旱半干旱草原矿区的相关研究,分析了煤矿生命周期阶段,给出了矿区不同生命阶段的发展过程与草原生态系统演变的空间关系;(2)解析了内蒙古东部干旱半干旱草原矿区生态效应累积特征,重点阐述了水、土、植被关键生态要素的累积源、累积途径及表征形式;采用趋势线分析法分析了内蒙古东部地区植被覆盖度时空累积变化趋势,1981—2015年61.29%的像元植被覆盖度变化不明显,通辽市西北部、赤峰市北部及呼伦贝尔市中部地区约16.86%的像元植被覆盖度呈现减少的趋势,呼伦贝尔市西部、兴安盟南部、赤峰市及通辽市西南部地区约21.85%的像元植被覆盖度呈现增加的趋势;(3)基于土地环境生态累积响应机理对生态承载力、生态累积效应、生态系统弹性3者关联关系进行了说明,提出了弹性调控的技术路径;定量研究煤矿全生命周期的生态累积效应有助于明确草原矿区生态系统演变规律,为干旱半干旱草原矿区生态修复提供理论基础和实践依据。

Located at the upper and middle reaches area of the Yellow River, the arid and semi-arid grassland region of Inner Mongolia is the ecological safety region known as the "Two Barriers and Three Belts",which includes many large-scaled coal mines and coal-fired power plants in China.The long-term growth and spatial expanded coal mining behavior have caused severe impacts on the mining area and surrounding ecological environments such as land degradation, groundwater decline and depletion, and biodiversity loss.Issues in this area have been raising concerns of the country and society which demands further research on the cumulative ecological effects.Past researches mainly focus on the analysis of the ecological effect of a certain ecological element or a certain period of time in arid and semi-arid grassland mining areas, however, the development of coal mines has a life cycle and complicated energy and material flow.This paper consists of three main parts:(1) The related research projects of arid and semi-arid grassland mining area in the world were reviewed.The life cycle stages of coal mines were analyzed, and the spatial relationship between different life stages development of mining area and the evolution of grassland ecosystem was provided.(2) The accumulative characteristics of ecological effects in arid and semi-arid grassland mining area in eastern Inner Mongolia were analyzed, and the accumulation sources, accumulation methods and representation forms of key ecological elements of water, soil and vegetation were emphasized.By using trend line analysis method, the temporal and spatial cumulative change trend of vegetation coverage in eastern Inner Mongolia was analyzed.The results showed that 61.29% of the pixel vegetation coverage in eastern Inner Mongolia were subtly changed from 1981 to 2015,about 16.86% of the pixel vegetation coverage in the northwest of Tongliao City, the north of Chifeng City, and the central area of Hulunbuir tended to decrease, and about 21.85% of the pixel vegetation coverage in the west of Hulunbuir, the south of Xing’an League, Chifeng City, and the southwest of Tongliao City tended to increase.(3) Based on the mechanism of the land environment ecological accumulation response, the relationship among ecological carrying capacity, ecological accumulation effect and ecosystem elasticity were explained, and the technical path of elastic regulation was proposed.Quantitative research on the ecological cumulative effects of the entire life cycle of coal mines is a promising way to understand the evolution patterns of ecosystem in grassland mining area, and build theoretical and practical foundations for ecological restoration in arid and semi-arid grassland mining area.