“双碳”目标下农地细碎化对植被碳汇的影响研究

STUDY ON THE IMPACT OF FARMLAND FRAGMENTATION ON VEGETATION CARBON SEQUESTRATION UNDER THE “DUAL CARBON” TARGET

关键词:  农地细碎化  碳汇  空间溢出  土地治理  农业综合开发

Key words:  farmland fragmentation  carbon sequestration  spatial spillover  land management  agricultural comprehensive development

摘要:

目的 提升植被碳汇被视为应对气候变化、如期实现“双碳”目标的重要抓手。尽可能全面地识别农地细碎化对植被碳汇的影响，能够从侧面展示农地细碎化治理蕴藏的生态价值。方法 文章基于卫星遥感数据，测算2001—2019年中国省级农地细碎化和植被碳汇水平，采用双向固定效应模型和空间计量模型实证考察农地细碎化对植被碳汇的影响。结果 （1）农地细碎化会显著降低植被碳汇，农地细碎化指数每增加1%，植被碳汇降低0.127 4%。（2）从农地细碎化维度来看，面积和分布细碎化均会显著降低植被碳汇。（3）从土地覆被类型来看，农地细碎化的影响并非局限于农地，同样会降低林地和草地碳汇，农地细碎化指数每增加1%，林草碳汇降低0.138 5%。（4）从空间关联来看，农地细碎化的影响并非局限于当地，同样会降低周边地区植被碳汇，存在空间溢出效应。（5）农业综合开发的土地治理项目能够降低农地细碎化对植被碳汇的负面影响，且相较于自筹资金，财政资金的治理效应更优，相较于农地治理，生态综合治理的治理效应更优。结论 应加强“生命共同体”系统思维，全面认知农地细碎化影响植被碳汇的广度和深度，重视农地细碎化治理的生态价值。在农地细碎化治理中充分发挥政府的主导作用，将生态保护和修复列为农地细碎化治理的前提。

Abstract:

Improving vegetation carbon sequestration is regarded as an important tool to cope with climate change and achieve the "Dual Carbon" target on schedule. This research aims to show the ecological value of farmland fragmentation management by identifying the impact of farmland fragmentation on vegetation carbon sequestration as comprehensively as possible. Based on satellite remote sensing data, this research calculated the level of Chinese provincial farmland fragmentation and vegetation carbon sequestration from 2001 to 2019. On this basis, it used two-way FE model and spatial econometric models to explore the impact of farmland fragmentation on vegetation carbon sequestration. The results showed that farmland fragmentation had a significant negative impact on vegetation carbon sequestration, with each 1% increase in the farmland fragmentation index reducing vegetation carbon sequestration by 0.127 4%. From the perspective of farmland fragmentation dimensions, area and distribution fragmentation both had a significant negative impact on vegetation carbon sequestration. From the perspective of land cover type, the impact of farmland fragmentation was not limited to farmland, but also had a significant negative impact on carbon sequestration of forest and grassland, with each 1% increase in the farmland fragmentation index reducing carbon sequestration of forest and grassland by 0.138 5%. From the perspective of spatial association, the impact of farmland fragmentation was not limited to the local area, but also had a significant negative impact on vegetation carbon sequestration in the surrounding areas, which showing a significant negative spatial spillover effect. Further study showed that land management projects of Agricultural Comprehensive Development(ACD) could reduce the negative impact of farmland fragmentation on vegetation carbon sequestration, and the impact of financial funds was better compared with self-financing, and the effect of ecological integrated management was better compared with farmland management. Therefore, we should strengthen the systemic thinking of "Life Community", comprehensively cognize the scope of the impact of farmland fragmentation on vegetation carbon sequestration, and attach importance to the ecological value of farmland fragmentation management. In farmland fragmentation management, we should give full play to the leading role of the government and make ecological protection and restoration a prerequisite for the farmland fragmentation management.