【作者】 成六三；

【导师】 吴普特；

【作者基本信息】 中国科学院研究生院（教育部水土保持与生态环境研究中心） ， 土壤学， 2011， 博士

【摘要】 退耕还林(草)工程是我国投资最大、涉及面最广、工序最复杂的生态建设工程之一,对其生态、社会、经济效益和综合效益的分析与评价对后续退耕还林(草)工程政策制定、区域土地资源可持续利用,以及社会经济可持续发展具有重要意义。本论文以地处陕北黄土丘陵区的研究区为研究区域,通过收集森林资源清查数据和统计年鉴资料,并结合野外参与式农户调查和退耕地土壤养分(全氮、全磷、全钾及有机质含量)实地测定,采用耕地压力指数和定位理论模型等方法,对该区退耕还林(草)工程生态、经济、社会效益及其综合效益进行了评价,并对后续政策进行了探讨,取得了以下主要结论:⒈在分析退耕还林(草)工程生态因子—植被、土壤和水文动态变化过程基础上,采用生态经济方法估算出了研究区(绥德县、米脂县、佳县、吴堡县、清涧县和子洲县)退耕还林(草)工程涵养水源、固土保肥、固碳制氧、保护生物多样性、净化空气和改善局地小气候六大生态服务功能的总价值分别为72×10~8元、83×10~8元、80×10~8元、116×10~8元、97×10~8元、91×10~8元。其中,固土保肥价值量最高(50%～92%),其次是固碳制氧(7%～48%),涵养水源、净化空气、保护生物多样性和改善局部小气候总和价值不到3%。⒉对比分析了区域退耕还林(草)工程实施前后农业产业比重、农户收入结构、农村剩余劳动力转移以及GDP等经济指标的变化特征,表明退耕还林(草)工程实施对区域产业结构调整、优化配置生产要素和地方经济发展有重要作用。运用通径分析和线性回归相结合的方法,得出了1998-2008年米脂县、绥德县、佳县、吴堡县、清涧县和子洲县退耕还林(草)工程对其区域农业产业结构调整力度系数分别为50.5%、23%、4.2%、47%、5%和36%;对其区域农村剩余劳动力的转移的能力分别为2.1人/hm~2、1.1人/hm~2、1.1人/hm~2、2.2人/hm~2、0.3人/hm~2和3.2人/hm~2。⒊利用定位理论模型和耕地压力指数模型对区域退耕还林(草)工程引发的主要社会效应进行了定量评价。1998-2008年绥德县、米脂县、佳县、吴堡县、清涧县和子洲县退耕农户对退耕还林(草)工程的满意度分别为0.85、0.91、0.8、0.81、0.83、0.82;另一方面,得出1998-2008年绥德县、米脂县、佳县和子洲县实施退耕粮食补贴对降低县域耕地压力所起的作用比较显著,吴堡县和清涧县不显著。⒋采用频率分析和专家咨询相结合的研究方法,对退耕还林(草)工程的影响因素进行了探讨,构建了由生态效益指标——涵养水源、固土保肥、固碳制氧,经济效益指标——农业产业结构调整、GDP与第一产业产值的比例、农村剩余劳动力转移,社会效益指标——区域粮食安全和农户对工程满意度等指标构成的退耕还林(草)工程综合效益评价指标体系。运用灰色关联度模型对研究区退耕还林(草)工程综合效益进行了评价,其综合效益评价评分顺序:子洲县(73.5)﹥米脂县(73.3)﹥吴堡县(67.7)﹥清涧县(62.5)﹥绥德县(59.1)﹥佳县(51.3)。结果表明综合效益得分高的,其单项效益不一定高;综合效益得分低的,其单项效益不一定低。综合效益评价对协调生态、经济和社会发展有重要意义。⒌结合生态、经济、社会效益及其综合效益评价结果,分析了退耕还林(草)工程实施的政策效率和建设速率。研究表明国家实施退耕还林(草)工程投入产出比例为1:20以上,工程政策取得了很高的效率,但粮食补贴折成现金兑换政策对低收入的退耕农户有效性较低。1998—2008年退耕还林(草)工程建设速率不同程度影响了区域粮食生产。综合以上研究结果,建议进一步加强退耕还林(草)工程的科学规划和实施,并加大今后财政的扶持力度以巩固现有成果,特别是生态成果。更多还原

【Abstract】 The Grain for Green project is one of largest ecological constructions in China as its large investment, wide aspects considered, and complicated processes, the evaluations of its equinoctial, economical and social benefits of the project is of great importance for policy construction, sustainable land resource, and economical and social development in the Loess Plateau. The paper takes a case of study on the south Yulin city to illustrate comprehensively such effects on the Grain for Green project in the loess plateau. Based on data of forest resources Inventory and socio-economic statistical yearbook in combined with soil analysis(TN,TP,TK and SOM) and interviewing questionnaire(120 samples) with face to face , it is evaluated by pressure index on cropland and localization theory model. The paper evaluated the ecological benefits, economic benefits, social benefits and comprehensive effects for the Grain for Green Project, and some evaluable conclusions were obtained as follows:⒈Based on analysis of the dynamic changes of forest-grass vegetation, soil surface and hydrology characteristics for the Grain for Green Project, The paper evaluated the value of service function of forest ecosystem by soil and water conservation, preservation of fertility, carbon fixing oxygen replacement, biodiversity protection, dust purification and improvement of local climate in Suide, Mizhi, Jiaxian, Wubu, Qingjian and Zizhou county, are 72×10~8 yuan,83×10~8 yuan 80×10~8 yuan,116×10~8 yuan,97×10~8 yuan,91×10~8 yuan, respectively. The value of service function for the conservations of soil and fertility is the largest shares, carbon sequestration and oxygen replacement is the second, but the sum of biodiversity protection, and dust purification of in air and the improvement of local climate are less than 3%.⒉The paper analyzed contritely economic indicators of agriculture, value structure of farmers’incomes, transfer of surplus labor and GDP on or about implementing the Grain for Green Project. Using the methods of path analysis and regression analysis, the contributions of the Grain for Green Project affecting agricultural structure adjustment are 50.5%,23%,4.2%,47%,5% and 36% in Suide, Mizhi, Jiaxian, Wubu, Qingjian and Zizhou county, respectively. The transfer of surplus laboring rural areas are 2.1 persons/hm~2, 1.1 persons/hm~2, 1.1 persons/hm~2, 2.2 persons/hm~2, 0.3 person/hm~2 and 3.2persons/hm~2, respectively. The results indicate that the Grain for Green Project has been improved local economical development by adjusting production structures in rural areas.⒊The quantitative evaluation was made for the social benefit of the Grain for Green Project by using models of orientation theory and pressure index of cultivated land. The farmers’satisfactory degree to the project are 0.85, 0.91, 0.8, 0.81, 0.83and 0.82 in Suide, Mizhi, Jiaxian, Wubu, Qingjian and Zizhou county, respectively. Subsidy alleviates the pressure on food security that vary counties where population densities differ,Where pressure index of cultivated land have been higher risks in Jia county and Wubu county, and been lower levels in Mizhi, QingjianSuide and Zizhou counties.⒋Based on frequency analysis in conjunction to expert enquiry, the factors influencing the Grain for Green Project were discussed in this paper, and a comprehensive evaluation system by integrated the index of ecological effect such as soil conservation and carbon sequestration, economical benefit such as agricultural industry structure adjustment, the percentage of production value of primary industry as well as rural labor force transfer, and social benefit such as regional food security and the farmers’satisfaction for the Grain for Green Project was constructed. Using Grey Correlation Degree Analysis method, the comprehensive benefits from the Grain for Green Project was evaluated, and the sequence for the six counties was as follows: Zizhou(73.5)﹥Mizhi(73.3)﹥Wubu(67.7)﹥Qingjian(62.5)﹥Suide(59.1)﹥Jiaxian(51.3). The result indicates that integrated higher score didn’t mean higher score for a single benefit, and vice versa. The evaluation based on integrated benefits for the Grain for Green Project is of great importance for ecological economical society sustainable developments.⒌Combined with the evaluations of ecological, economic, social and their comprehensive benefits from the project, this paper analyses the effectiveness of the policy and the implementing dimensions of the Grain for Green Program. The research showed that the ratio of input to output in the engineering was above 1:20, indicating high effectiveness of the project. However, the policy that grain subsidy was converted to the cash was lower for low-income farmers. The construction dimension of the Grain for Green Program affected regional food production in different extents during the period of 1998 to 2008.Based on the above research results, we suggested further improving the scientific planning and implementation of Grain for Green Program, and strengthening the financial support in future in order to consolidate the existing achievement, especially in ecological achievement.更多还原