【作者】 郭雨华；

【导师】 孙保平；

【作者基本信息】 北京林业大学 ， 水土保持与荒漠化防治， 2009， 博士

【摘要】 国家退耕还林工程已经实施八年,工程效益的好与坏,是项目决策与管理者十分关注的问题。国家林业局决策启动了北方地区退耕还林工程效益监测与评价课题。该课题选择了青海大通县、宁夏盐池县、新疆奇台县、陕西吴旗县、安塞县、山西中阳县、甘肃定西县、河北涉县、内蒙古卓资县等9个工程县作为效益监测与评价的基地,对退耕还林工程建设效果进行全面系统的科学评价。本文以9个工程县中的青海大通县、宁夏盐池县、新疆奇台县三个工程县为研究对象,采用野外试验监测、遥感影像分析等手段方法,统计分析国内外相关研究内容,并结合我国退耕还林工程的实际情况,建立了退耕还林工程综合效益评价指标体系,从分析退耕还林的生态、经济和社会效益入手,开展退耕还林工程的综合效益监测与评价。主要研究结果如下:1、应用物种多样性分析不同植物群落物种组成。结果表明:退耕还林地从低龄林向高林龄的发展过程中,生物多样性经历了一个物种丰富度、多样性“低-高-低”、而优势度、均匀度“高-低-高”的变化过程。在退耕还林植被演替发展过程中,群落物种多样性并不呈单调上升(或下降)的变化趋势。因此,在进行植物组成评价时,要充分考虑到植物群落演替的规律性。2、以土壤剖面特征指数、土壤总孔隙度、毛管孔隙度、最大持水量、毛管持水量、土壤团粒、大团聚体含量、土壤有机质、全氮、速效钾、CEC、PH值等参数为指标,评价退耕还林地土壤理化性质,结果表明,随着退耕时间的延伸,退耕还林还草地不断从农耕地剖面向天然次生林地剖面的层次发育过渡,理化性质越来越接近于天然林地。3、水文效应分析表明,植物群落植冠层截留量、枯落物持水量随退耕年限的延长而增大。枯落物容水量与枯落物厚度、枯落物蓄积、退耕年限、生物量相关性显著。4、以大通县、盐池县、奇台县退耕还林不同时期TM影像数据为基础,对退耕还林各时期土地利用/覆被及景观格局变化进行了研究,分析结果表明:实施退耕还林工程后,大通县、盐池县、奇台县耕地面积均减少,从退耕还林前到2007年,分别减少了0.79%、2.5%、0.08%;林地面积分别增加了8.89%、2.07%、0.43%,大通县草地面积减少了6.78%,主要是由于人为原因导致草场退化,未利用地减少了2.25%;盐池县草地面积增加了1.61%,未利用地减少了约3%,部分未利用地转化为草场;奇台县草地面积由2000年的9.26%增加到2007年的13.03%,未利用地减少了4.17%。5、按盐池县不同乡镇边界将盐池县划分为不同空间地域单元,提取并分析了不同乡镇荒漠化程度综合指数,揭示了该区荒漠化发展程度的地域分布规律。结果表明,盐池县从北向南荒漠化程度总体上呈现逐渐减弱的趋势。6、采用机会成本法、恢复费用法等方法,计算出大通县2000～2007年退耕还林工程生态效益初始总价值为13.14亿元;盐池县2000～2005年退耕还林工程生态效益初始总价值为17.61亿元;奇台县2000～2006年退耕还林工程生态效益初始总价值为3.77亿元。7、采用典型调查与宏观分析相结合对退耕还林工程的间接经济效益、社会效益进行了评价。更多还原

【Abstract】 The Land Conversion Program has been implemented for eight years,and the project decision-makers and managers are very concerned about that the effectiveness is a good or bad.State Forestry Administration launched the issues of effective monitoring and evaluation of the Land Conversion Program in Chinese North Region,and selected nine project countries in North China such as Datong,Yanchi,Qitai,Wuqi,Ansal,Zbongyang,Dingxi,Shexian and Zhuozi as the base for effective monitoring and evaluation,to evaluate the effectiveness comprebensively and systematically.This paper taking Datong,Yanchi and Qitai in the nine nine project countries as the studying object,and combining with field monitoring,statistical report and 3s,a set of criteria and indicators for assessing the holistic benefits of LCP was built.Taking the environment situation before the program testing as the contrast,has given an objective evaluation to the comprehensive benefit in the Land Conversion Program testing region.The main result shows as following:1."Species diversity"is proposed to comprehensively evaluate species composting.The result shows that,on the sequence from the newly converted lands to long-term converted lands,the Shannon-Wiener diversity index and Gleason richness index shows a "small-big-small"process,while the Simpson dominance index and Hill evenness index present a contrary process.On the process of community succession,species diversity doesn’t present a monotonously rise or drop trend.The result indicates that we should fully take the succession stage into consideration in the evaluation of species diversity.2.Taking some indexes such as soil profile index,soil total porosity,capillary porosity,the largest water-holding capacity,capillary water holding capacity,soil aggregate and large aggregate content,soil organic matter,total N,available K,CEC,PH,etc.to evaluate soil physical and chemical properties. The result shows that,As an extension of time returning,the soil profile characteristics of returning farmland to forest is more and more close to the level of natural secondary forest,as well as soil physical and chemical properties.3.Study on hydrological effect sbows,rainfall interception amount of the tree canopies and water holding capacity of litter are increasing with the increase of converted years.The relationships between the water-keeping capacity of litter and the thickness of litter layer,accumulation of litter,converted year,biomass are according with significant correlation.4.Study on changes of landscape pattern and LUCC different periods by using TM image data of different periods of Datong,Yanchi and Qitai shows that the area of arable land of the three project countries decreased respectively by 0.79%,2.5%,0.08%after the implementation of Land Conversion Program;the area of woodland increased respectively by 8.89%,2.07%,0.43%;As Man-made causes,the grassland area of Datong decreased by 6.78%.While,the grassland area of Yanchi increased by 1.61%,part of unused land was converted to grassland;The grassland area of Qitai increased from 9.26%in 2000 to 13.03%in 2007;The area of unused land of the three project countries decreased respectively by 2.25%,3%,4.17%.5.Yanchi County is classified into different space and regional units by borders of towns,whose integrative index of desertification degree is extracted and analyzed by the paper,and the regional distribution discipline of the development of desertification is revealed:desertification degree decreases gradually on the whole from north to south in Yanchi County.6.The total initialization value of ecological benefit of the three project counties were calculated by using the opportunity cost method,renewing cost approach,and so on.The total initialization value of Datong,Yanchi,Qitai is 13.14,17.61,3.77 billion RMB.7.The indirect economic effect and social of LCP were assessed by integrated typical survey and macroscopic analysis.更多还原