基于碳汇的县南沟流域退耕林地补偿标准研究

补偿标准是退耕还林生态补偿的核心与难点,为探讨黄土高原退耕林地合适的补偿标准,论文基于清洁发展机制的国际背景,通过理论分析、实地测量与室内实验,把碳汇价值与退耕农户的机会成本相结合,构建了禁伐政策下退耕林地补偿标准的动态模型;并选取黄土高原退耕的代表流域——县南沟进行实证分析,依据退耕刺槐（Robinia pseudoacacia）林特性确定退耕的一个补偿周期为37 a,退耕地补偿过程与补偿标准分为两个阶段：退耕1~17 a,通过机会成本的计算,补偿的可执行标准为1 997.26元/(hm²·a);退耕18~37 a,通过碳汇模型进行测算,补偿的可执行标准为3 692.35元/(hm²·a)。人工刺槐纯林在补偿周期之后会逐渐出现灌木层和衰败现象,因此,这一补偿期结束后,应根据林地生态群落的变化再行核算并完善其补偿标准。将碳汇价值纳入补偿体系,能促使农民为提高碳汇产量自觉增强林地管护,巩固退耕成果。

Study on the Compensation Standard of Returning Farmland to Forest in Xiannangou Watershed from the Perspective of Carbon Sink

Quantitatively formulating compensation standard is a core and difficulty to establish ecological compensation mechanism. In order to explore appropriate compensation standard for returning farmland to forest and provide reference for national and regional compensation policy formulation in the Loess Plateau, in the international background of the Clean Development Mechanism and logging ban policy, this paper builds a dynamic model of compensation standard for returning farmland to forest by combining value of carbon-sink with farmer’s opportunity cost. Through theoretical analysis and field measurements, combined with laboratory experiments, we made an empirical study of the representative watershed—Xiannangou Watershed on the Loess Plateau. The compensation cycle is determined to be 37 years according to the growth characteristics of the Robinia pseudoacacia forest in the Xiannangou Watershed. The compensation process and standard are divided into two stages. During the 1st-17th years of returning farmland to forest, when the farmer’s opportunity cost is greater than the value of carbon-sink, we should compensate for the actual economic loss of farmers. Executable standard of compensation is 1 997.26 yuan/(hm²·a) according to the oppor-tunity cost. During the 18-37th years of returning farmland to forest, the value of carbon-sink is greater than the farmer’s opportunity cost, which means that the industry substitution has completed. Executable standard of compensation is 3 692.35 yuan/(hm²·a) according to carbon sink model. In summary, the value of carbon-sink accounts for 89.50% of the total compen-sation in the compensation period. Artificial Robinia pseudoacacia forest will gradually generate shrubs and decline after the compensation period, therefore, the compensation standard should be calculated and perfected again in accordance with the change of forestland ecological community after the compensation period finished. Involving the value of carbon-sink into the compensation system can push farmers to manage and protect forestland consciously for improving the carbon sink production, which is beneficial to consolidate the achievements of the Grain for Green Program on the Loess Plateau.