退牧还草地土壤有机碳固持动态与驱动机制研究进展  

Dynamics and driving mechanisms of soil organic carbon sequestration in grasslands after grazing exclusion:A review

作　　者：邓蕾[1,2,3] 李继伟 瞿晴 石经玮 上官周平[1,2,3] DENG Lei;LI Jiwei;QU Qing;SHI Jingwei;SHANGGUAN Zhouping(State Key Laboratory for Soil Erosion and Dryland Farming on the Loess Plateau,Northwest A&F University,Yangling 712100,Shaanxi,China;College of Soil and Water Conservation Science and Engineering(Institute of Soil and Water Conservation),Northwest A&F University,Yangling 712100,Shaanxi,China;Institute of Soil and Water Conservation,Chinese Academy of Science and Ministry of Water Resources,Yangling 712100,Shaanxi,China)

机构地区：[1]西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100 [2]西北农林科技大学水土保持科学与工程学院(水土保持研究所),陕西杨凌712100 [3]中国科学院水利部水土保持研究所,陕西杨凌712100

出　　处：《应用生态学报》2024年第11期3208-3216,共9页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(42277471)资助。

摘　　要：退牧还草被认为是恢复退化草地结构和功能的最有效措施,在提高生态系统固碳能力方面发挥着重要作用。阐明退牧还草后土壤有机碳的固持动态及其驱动机制,是全球变化下碳循环研究的热点和前沿问题。本文综述了退牧还草地土壤有机碳固定动态及其驱动机制,剖析了退牧还草地土壤有机碳固持动态,探讨了退牧还草地植物碳输入和微生物群落对土壤有机碳固持的影响机制,分析了光合碳输入和凋落物分解对土壤有机碳固持的影响,以及植物和微生物残体碳对土壤有机碳固持的贡献。长期退牧还草通过增加植被碳输入,改善微生物的结构和功能,提升土壤稳定性有机碳(如矿物结合态有机碳、植物和微生物残体碳等)含量或比例,进而减少土壤有机碳矿化效率和提高微生物碳利用效率,从而促进土壤有机碳库的积累。退牧还草受初始有机碳水平的影响,土壤有机碳固定整体呈“增加、稳定”和“降低、增加、稳定”两种变化趋势。未来应加强在土壤有机碳组分动态、土壤有机碳输入的碳流过程、土壤有机碳的分解过程及其微生物驱动机制等方面的研究。Grazing exclusion is the most effective measure to restore the structure and function of degraded grasslands,and plays a crucial role in increasing ecosystem carbon(C)sequestration capacity.The dynamics and dri-ving mechanisms of soil organic carbon(SOC)after grazing exclusion have attracted great concerns,especially in the context of global change.By reviewing the current research on the SOC sequestration dynamics and its driving mechanisms after grazing exclusion,we aimed to clarify the SOC sequestration dynamics,explore the influencing mechanisms of plant C input and microbial community on SOC,analyze the driving mechanisms of photosynthetic C input and litter decomposition on SOC sequestration,and explore the contribution of plant and microbial necromass C to SOC sequestration after grazing exclusion.Long-term grazing exclusion improve the structure and function of soil microorganisms by increasing plant carbon inputs,and increase the content and proportion of soil stable organic C(such as mineral-associated organic C,plant and microbial necromass C,etc.),reducing mineralization efficiency of SOC and improving microbial C utilization efficiency,and consequently promoting SOC accumulation.In addition,SOC sequestration shows two trends of“first increasing and then stabilizing”and“first decreasing,following increasing and then stabilizing”,which are affected by the initial SOC level.Future studies should be strengthened in the SOC fraction dynamics,the C flow of SOC input,the decomposition process of SOC,and the microbial dri-ving mechanism after grazing exclusion.

关 键 词：固碳动态 草地 植物碳输入 土壤有机碳 土壤微生物 植被恢复 

分 类 号：S812.2[农业科学—草业科学]