底土有机碳特征、影响因素与作用机理研究进展  

Research Progress on the Characteristics,Influencing Factors and Mechanisms of Subsoil Organic Carbon

作　　者：郭思宇 周萍[2] 黄运湘[1] 郭晓彬 陈香碧[2] 吴金水[2] GUO Siyu;ZHOU Ping;HUANG Yunxiang;GUO Xiaobin;CHEN Xiangbi;WU Jinshui(College of Resources,Hunan Agricultural University,Changsha 410128,China;Key Laboratory of Agro-ecologicalProcesses in Subtropical Region&Changsha Research Station for Agricultural and Environmental Monitoring,Institute of Subtropical Agriculture,Chinese Academy of Sciences,Changsha 410125,China)

机构地区：[1]湖南农业大学资源学院,湖南长沙410128 [2]中国科学院亚热带农业生态研究所,亚热带农业生态过程重点实验室&长沙农业环境观测研究站,湖南长沙410125

出　　处：《湖南生态科学学报》2023年第3期77-84,共8页Journal of Hunan Ecological Science

基　　金：国家自然科学基金(42177293,41671242,42130716);科技基础资源调查专项课题(2021FY100504)。

摘　　要：土壤有机碳是陆地生态系统最大的碳库,其源/汇特征深刻影响全球气候变化。土壤碳库中约50%以上的碳储存在20 cm以下的底土层,底土有机碳是土壤碳库的重要组成部分,对全球碳循环具有重要影响。底土碳库变化及其关键调控机制已成为土壤学研究领域的热点之一。本文综述了国内外有关底土有机碳变化特点、影响因素及其周转与稳定的关键机理等方面的研究进展。综合国内外的研究表明,底土有机碳并不稳定,其对植被、环境因素以及土地利用变化等的响应比较敏感,从而影响整个土壤剖面碳库的源/汇功能并反馈于全球气候变化。影响表土有机碳周转与稳定的主要作用机理在底土中同样适用,包括团聚体物理保护、有机碳自身的化学结构稳定以及与矿物质的化学键合稳定等。但是,底土独特的土壤特性和生物特性,导致有机碳周转与稳定机理的作用程度可能与表土存在差异。由于当前对底土有机碳时空变化及其源汇特征的了解尚不明确,未来研究需要系统阐明底土有机碳周转的关键作用机理,并将底土碳库周转纳入区域土壤碳循环过程与固碳减排潜力评估。Soil organic carbon(SOC)is the largest carbon stock of terrestrial ecosystem,and its source/sink characteristic plays key role in global climate change.Subsoil below the horizon of 0~20 cm contributes more than 50%which constitutes the important part of soil carbon pool and profound influence on global carbon cycle.The dynamics of subsoil carbon pool and its regulated key mechanisms have become one of the hotspots in the field of soil science.In the present study,we reviewed the research progress on the dynamics and controlling factors,as well as the regulated key mechanisms of subsoil organic carbon at home and abroad.Studies at home and abroad have shown that organic carbon in subsoil is not stable and is sensitive to vegetation,environmental factors and land use changes,which influences the source/sink characteristics of soil profile carbon stocks and further gives feedback on global climate change.The key mechanisms of organic carbon dynamics and stability in the topsoil are also applicable in the subsoil,including the physical protection in soil coarse aggregates,structural stabilization of organic carbon,and chemical protection by binding with soil minerals.However,the relative importance of these mechanisms in the subsoil may differ from those in the topsoil,because of the unique soil characteristics and biological characteristics of the subsoil.Since the current understanding of the spatial and temporal variation of subsoil organic carbon and its source and sink c haracteristic is still insufficient,it is necessary to systematically clarify the key mechanisms of subsoil organic carbon dynamics in future studies,and to incorporate the subsoil organic carbon stock to regional soil carbon cycle process and carbon sequestration potential assessment.

关 键 词：底层土壤 土壤有机碳 碳周转与稳定 环境变化 人为管理 

分 类 号：S153[农业科学—土壤学]