农田土壤固碳潜力研究的关键科学问题  

Key Issues on Soil Carbon Sequestration Potential in Agricultural Soils

作　　者：孙文娟[1] 黄耀[1] 张稳[1] 于永强[1] 

机构地区：[1]中国科学院大气物理研究所大气边界层物理和大气化学国家重点实验室,北京100029

出　　处：《地球科学进展》2008年第9期996-1004,共9页Advances in Earth Science

基　　金：国家自然科学基金重点项目"三江平原沼泽湿地垦殖对地-气碳交换和土壤碳库影响的研究"(编号:40431001);国家自然科学基金面上项目"利用GIS与模型技术预测气候变化和CO2浓度升高对中国稻田甲烷排放的影响"(编号:40675075)资助

摘　　要：农田生态系统在陆地生态系统碳循环中扮演着重要的角色。增加农田土壤有机碳的固定不仅可减少大气CO2含量,而且对保障国家粮食安全具有举足轻重的作用。近年来评估土壤固碳潜力已成为国际科学界研究的热点和难点。但由于不同研究者对"潜力"范畴的界定不同,全球或区域尺度农田土壤固碳潜力的估算还存在很大的不确定性。所谓固碳潜力,即土壤碳的饱和水平或土壤所容纳碳的最大能力。这一能力受区域气候、土壤类型、农业管理措施的综合影响。故此,合理地评价固碳潜力,应综合考虑气候、土壤和农业措施诸因素,并将宏观尺度与微观尺度的研究结合起来。从固碳潜力概念范畴及研究方法出发,阐述了农田土壤固碳潜力的研究现状,并结合生物潜力和物理化学潜力的研究,提出区域农田土壤固碳潜力的计量方案,并就该研究领域亟需回答的科学问题进行了探讨。Ago-ecosystem plays an important role in terrestrial carbon cycling. Soil carbon sequestration in cropland can not only offset fossil fuel emissions but also contributes to food security. Though the evaluation of soil carbon sequestration potentials has attracted attentions worldwide, large uncertainties in estimating C sequestration potential on regional/national or global scales remain a big problem due to various interpretations of the ＂potential＂ among scientists. The paper reviewed up-to-date interpretations of ＂soil carbon sequestration potential＂ and the methods of estimating C sequestration potential in agricultural soils. Carbon sequestration potential, conceptually the maximum capacity of soil＇s holding carbon or the level of SOC （Soil Organic Carbon） saturation and stability, is usually vulnerable to climate, soil characteristics and agricultural practices. Reliable estimations of soil carbon sequestration potential should therefore integrate the influence of climate, soil structure/texture and field management as well as the coupling of macroscopic and microcosmic processes of carbon turnover in soils. An integrated methodology for estimating regional soil C sequestration potential was proposed in the paper with two concepts of biological and physicochemical potentials. Key issues and prospects on soil carbon sequestration in Chinese croplands were also addressed.

关 键 词：农田土壤 固碳 生物潜力 物理化学潜力 计量 

分 类 号：S158.2[农业科学—土壤学] S181[农业科学—农业基础科学]