土地利用碳排放效应及其低碳管理研究进展

土地利用是造成全球温室气体排放量迅猛增长的重要因素,但由于土地利用的碳排放在时间和空间上受社会经济活动与自然过程的共同作用,相对自然生态系统碳排放的过程和机制更加复杂,因此,其研究也越来越多地受到包括学者、政府决策者、企业、非政府组织等利益相关者的关注,并被诸多能源与生态环境领域的国内外重大科学研究计划列为核心内容。通过对土地利用的直接和间接碳排放效应及其低碳管理的国内外研究进展进行综述,较全面地对上述研究中已取得的成果以及尚存在的不足与挑战进行了总结,并对未来研究应如何完善现有研究的不足提出了几点展望,以期为科学编制低碳目标导向的土地利用规划提供理论基础和实践管理经验,从而全面引导城市的低碳发展。

Progress in research on land use effects on carbon emissions and low carbon management

Land use has played an important role in causing rapid increase of greenhouse gas emissions. As reported in the literature, nearly one third of global carbon emissions during the last hundred years has come from changes in land use/cover and the transformation of land management modes. In this paper, the latter is called the direct effect of land use on carbon emissions. The remaining two thirds of carbon emissions were caused by anthropogenic activities on different types of land. This is defined as indirect effect of land use on carbon emissions. Unveiling the mechanisms of how land use affects carbon emissions and determining the anthropogenic controls and regulatory countermeasures needed to achieve low-carbon targets are key research subjects with strategic importance for socioeconomic development. However, the mechanisms by which land use affects carbon emissions, especially in rapidly urbanizing regions, are still unclear, and are more complicated than those of natural ecosystems. This is because of the complex nature of land-use influenced both by human socio-economic and natural ecological factors. Thus, research relevant to these issues has been attracting more and more attention from stakeholders such as scholars, policymakers, enterprises, and non-governmental organizations. Such research has been targeted as core content in many scientific research programs in the energy and environmental disciplines around the world. In order to have a comprehensive understanding of the state of the art in land use effects on carbon emissions, and for low carbon management, this paper summarizes the achievements in the existing literature. It also provides a review of the existing gaps and challenges from the perspectives of carbon inventory accounting, mechanisms of both direct and indirect carbon emissions from land use, and carbon mitigation management. It was found that 1) in past decades, a large amount of research has been conducted on land-use-induced carbon-inventory accounting at both country and regional scales, and on the effect of land use on the carbon cycle of some typical natural ecosystems, such as forests and grasslands. In contrast, studies on the mechanisms of land use change driven both by socioeconomic and natural processes, and on their influence on carbon emissions at city scale, lag behind. 2) The current literature on low carbon management focuses more on the planning and regulation of specific types of land use, such as urban green space or residential land, or on the optimization of the amount and composition structure of total urban land. Systematic control and regulating principles, together with roadmaps for detailed implementation, have not yet been provided. Future studies aimed at correcting current deficiencies are proposed to provide the theoretical knowledge and practical experience needed for achieving low-carbon-target-oriented, land-use planning.