2010—2060年中国森林生态系统固碳速率省际不平衡性及调控策略

森林生态系统具有很高的固碳潜力,是陆地碳汇的主体。准确估算各省（自治区）森林生态系统固碳速率,是科学制定碳中和技术路线及相应调控政策的重要依据。然而,目前有关中国不同省份森林生态系统未来固碳潜力的研究非常罕见。利用中国森林生态系统固碳模型（FCS）并结合3种未来气候情景（RCP2.6、RCP4.5和RCP8.5）,定量评估了2010—2060年间各省现存森林生态系统的固碳速率。研究发现：中国区域内各省的森林生态系统固碳速率介于0.01~36.74 Tg C/a,平均值为(10.09±0.43) Tg C/a。省际间森林固碳速率存在非常大的差异,其中东部地区各省的单位面积固碳速率大于西部地区;但考虑到单位GDP固碳速率和人均固碳速率后则表现为西部地区明显更大。此外,各省人均碳固存速率与其人均GDP之间存在显著负相关关系。因此,省际间森林生态系统固碳速率存在明显的区域不均衡性,要真正地持续实现其碳汇潜力需要在技术和政策层面做出重大调整。结合中国贫困区与高生态碳汇区的重叠,不能仅仅依靠传统碳贸易,亟需研究制定符合中国特色的“区域碳补偿”措施,在保障区域协调发展的基础上使西部或不发达地区民众能自愿/自觉加强对森林的保护、保持甚至提升森林碳汇,使森林在实现碳中和战略中发挥更大作用。

Imbalance of inter-provincial forest carbon sequestration rate (2010-2060) in China and its regulation strategy

Forest ecosystem, as a predominant component of terrestrial ecosystem carbon sinks, has a high potential for carbon sequestration. Accurate estimation of the carbon sequestration rate in forest ecosystems at provincial level is a prerequisite and foundation for scientifically formulating the technical approaches of carbon neutrality and associated regulatory policies. However, research on future carbon sequestration rates (CSRs) for forest ecosystems for provincial-level regions (hereafter province) in China has rarely been reported. This paper quantitatively assesses the carbon sequestration rates of existing forest ecosystems of all the provinces from 2010 to 2060 using the Forest Carbon Sequestration model (FCS), in combination with large quantities of measured data in China under three future climate scenarios (RCP2.6, RCP4.5, and RCP8.5). Results showed that CSRs across provinces varied from 0.01Tg C/a to 36.74 Tg C/a, with a mean of (10.09±0.43) Tg C/a. There are apparent inter-provincial differences in view of forest CSRs. In terms of the spatial variations in CSRs on unit area basis within provinces, the eastern region has larger capacity to sequestration than the western region, while the western region has greater CSR per unit GDP and per capita. Moreover, there are significant negative correlations between the CSRs per capita in each province and the corresponding GDP per capita, under an assumption that GDP per capita is constant across provinces. In summary, there is a significant regional imbalance of the CSR among provinces, and major technical and policy changes are needed to realize their carbon sink potential sustainably. In view of the overlap between China's poor areas and high ecological carbon sink areas, it is indicated that the existing policies to support the traditional carbon trading are far from sufficient. It is urgent to take China's regulatory measures such as "regional carbon compensation" in line with the Chinese characteristics, so that people in western or underdeveloped regions can voluntarily/consciously strengthen forest protection and enhance forest carbon sinks on the basis of ensuring coordinated regional development, thus China's forests can play a greater role in carbon neutrality strategies.