【作者】 曾明明；

【导师】 牛叔文；

【作者基本信息】 兰州大学 ， 环境科学， 2008， 硕士

【摘要】 玛曲县是黄河上游地区的主要水源涵养地,草地生态系统服务价值巨大。畜牧业也是该地区人们主要的生产和生活方式。近些年来由于全球气候变化和人为因素的影响,黄河沿岸出现了沙化,这不仅明显制约了牧区经济的发展和当地臧族群众生活水平的提高,而且直接威胁到黄河流域的生态安全。在西部大开发的背景下,研究高寒草地生态系统与自然、人为因子的互动关系对解决玛曲县的草地退化问题意义重大。本文通过实地调查、历史资料分析和定量研究的方法,在阐明玛曲县进行草地生产的自然、社会、经济现状基础上,分析玛曲县草地退化现状及其对当地生态环境、社会、经济系统的危害,采取理论与实践相结合、定性与定量相结合的方法分析草地退化成因及其主导因子,基于NPP的估算界定草场的超载过牧,采用道格拉斯生产函数模拟温度和超载对草地沙化的影响程度,并基于玛曲县草地生态系统服务价值的核算,提出了草地生态系统的管理对策,其设计应以改变超载过牧、防治草地退化和改善牧民生活水平为目标,以生态补偿为核心,建立起有利于草地资源可持续利用的配套政策。补偿依掘则应基于生态系统服务价值的核算来确定。取得以下主要的结论:1.玛曲草地退化相当严重。近20年来,玛曲黄河沿岸草场沙化面积日趋扩大,且发展速度越来越快,从1985年到2003年的17年间,年均沙化速度达到23.27%。该区生态环境不断恶化,严重制约了当地牧业生产和地方经济的发展。2.玛曲草地退化是自然因素和人为因素的共同作用造成的。影响玛曲草地沙化的因子较多,自然因素主要是温度升高,特别是≥0℃积温的增加;人为因素主要是超载过牧。50多年来玛曲草地的实际载畜量持续上升,从低于理论载畜量到超载过牧。用生产函数分析温度升高和超载过牧对草地沙化的作用程度,结果表明,温度升高的影响占34.39%,超载过牧占65.61%。草地沙化是过牧的累加效应达到一定程度时才出现的,累加超载量每增加1万个羊单位会造成3.14hm~2草地沙化。3.基于玛曲草地生态系统的巨大服务价值,合理进行生态补偿。经过对玛曲生态系统服务价值的核算,现价达96.25亿元/年。鉴此,生态补偿的标准应以超载牲畜所带来的收益作为补偿的价值量。4.玛曲生态环境管理的对策包括:产业开发、草地管理和技术推广、生态移民和牧民定居、能源开发以及控制人口增长和促进社会进步等方面。更多还原

【Abstract】 Maqu County is the the main water conservation region in the Upper Yellow River and with great value of grassland ecosystem services. Livestock husbandry is also the main production and living patterns for local people. For recent years grassland was subject to serious degradation and desertification due to global climatic change and artificial factors, which not only obviously restricted the development of economy in Pastoral Areas and the improvement of local Tibetan people’s living standard, but also directly threatened to the ecological safety of the region along Yellow River. So under the background of the Great Development of West Region, it’s important for us to study on the interactive relationship between alpine grassland and narural & artificial factors for solving the issue of grassland degradation in Maqu County.By means of field survey, history datum analytic methods and quantitative study, on the base of natural, social, economic conditions of the source region, the author analyzed the status of grassland degradation and its harm to local ecoenvironment, society and economy systems, and studied the cause of grassland degradation and the leading factors by the methods of combining theory with practice, combination of qualitative and quantitative. According to the estimation of NPP, the quantity of overgrazing was defined. The effects of temperature and overloading on grassland desertification were simulated by Cobb-Dauglas function. And management countermeasures were proposed based on ecosystem service valuation of grassland in Maqu County, which should take for changing overgrazing, controling grassland desertification and improving people’s living standard as center and establish supporting policies favorable to grassland resources sustainable utilization. Conclusions were as follows:Grassland degradation is quite serious in Maqu County. For recent 20 years, the area of grassland desertification along the Yellow River extended gradually. The average speed of desertification reached 23.27% during the 17 years from 1985 to 2003. The serious eco-environment problems of the region gravely restricted the development of local husbandry production and regional economy.The causes of grassland degradation in Maqu County are double effects of natural factors and artificial factors. The key natural factor that affected grassland desertification in Maqu County was temperature increasing, especially the accumulated temperature of≥0℃; and the key artificial factor was overgrazing. Actual carrying capacity of Maqu grassland has increasing persistently during the 50 years. The effect degree of temperature increasing and overgrazing on desertification was analezed using production function, the results were that the effect of the temperature increasing to grassland desertification accounted for 34.39% and overgrazing for 65.61%. Desertification phenomena appear on grassland when the accumulation effect of overgrazing reaches some degree. That accumulated number of overstocking increases newly ten thousand sheep units would cause the area of 3.14hm~2 for grassland desertification.The value of ecosystem services in Maqu County is so large as to 96.25×10~8 yuan/a now. Based on the calculation of ecosystem services, the standard of ecological compensation should be the valuation brought by the overload. The policy contents of ecological management should include: industrial development, ecological emigration and herdsmen settlement, grazing management, technology popularizing, the control of population growth and promoting social progress.更多还原