退耕地林草植被碳汇及与农业生态经济系统的关系-以陕西省县南沟流域为例

《联合国气候变化框架公约》签订后,国内外学者开展了大量碳汇方面的工作,而碳汇与农业生态经济系统关联性的研究较为薄弱。因此,作者通过野外采样和室内试验,结合课题组累积的15年调研资料,利用灰色关联分析方法,分析县南沟流域碳汇与农业生态经济系统的关系,以期为碳汇与农业生态经济系统的研究与实践提供参考。结果表明:退耕还林(草)工程实施以来,林草碳汇显著增加,年碳汇增量从2523.17 Mg增加至4562.06 Mg。在碳汇增加的过程中,农业土地利用结构和产业结构(以收入结构为表征)的演替对其产生了较强的正向效果,土地利用结构调整通过扩大林草面积增加碳汇量;产业结构的变化通过非农收入的增加和高效设施农业的发展减轻对土地的压力,进而促进和稳固土地利用结构。根据研究结果,建议今后应进一步优化农业系统结构,以促使林草碳汇的稳定增加。

Carbon Sequestration of Forest and Grass in Abandoned Farmland and Relationship of Carbon Sequestration with Agricultural Eco-economic System:A Case Study of the Xiannangou Watershed in Shaanxi Province

International and domestic researchers have carried out a lot of the work in carbon sequestration since The United Nations Framework Convention on Climate Change was published, but research on the relationship between carbon sequestration and agricultural ecological economic system is still comparatively weak. In order to provide reference about research and practice of the relationship between carbon sequestration and agricultural eco-economic system, this study analyzed carbon sequestration responses to the agricultural eco-economic system in Xiannangou Watershed using grey correlation analysis method combined field sampling, laboratory experiments, and 15 years peasant household survey data. The results showed that Carbon sequestration of forest and grass increased significantly after the implementation of the Grain for Green Project, and annual carbon sequestration increased from 2523.17 Mg to 4562.06 Mg during the period of 1998-2014. Agricultural land use structure and industrial structure had significant effect on carbon sequestration. The adjustment of land use structure increasing the area of forest and grass increased the amount of carbon sequestration; the change of the industry reduced the land pressure and then promoted and secured land use structure by the development of efficient facilities agriculture and the increase of system income and non-agricultural income. It showed that agricultural ecological economic system succession process produced a strong positive effect on carbon sequestration potential. According to the results, we should further optimize the structure of agricultural system, adjust the stand structure, and improve the quality of grass to promote a steady increase of carbon sequestration.