土壤团聚体结构与有机碳的关系、定量研究方法与展望

Soil Aggregate Structure and the Relationship between Organic Carbon,Quantitative Research Methods and Prospect

近些年土壤固碳研究受到广泛关注。在诸多影响土壤固碳的因素中,团聚体结构对土壤有机碳的物理保护机制是研究的焦点。土壤中原始有机碳在土壤团聚体和团聚体结构形成中发挥着不可替代的作用,土地利用方式、耕作方式以及施肥措施发生变化后,团聚体及其结构在土壤有机碳固定中的作用变得更加凸显。团聚体结构包含众多的孔隙,这些孔隙的大小、数量、形状以及空间分布等都会影响土壤中水分运移、植物根系生长、土壤生物活动以及土壤有机碳分配,它们相互作用影响土壤中有机碳的固定。本文分析了水分、植物根系以及土壤生物与团聚体孔隙结构之间的关系,阐述了这些因素在土壤有机碳变化中所起的作用,并对目前研究的不足进行了概述。同时,阐述了不同CT(Computed Tomography,CT)技术在土壤团聚体结构探测中的应用及其对结构数据的提取方法,探讨了团聚体孔隙结构对有机碳固定的影响,展望了团聚体结构对有机碳固定影响需要加强的研究内容。参66。

Soil carbon sequestration has turned into a key issue in the global carbon research and been given great attentions .The physi-cal protection of soil organic carbon through aggregates is one of the most important mechanisms of C sequestration .The initial soil or-ganic carbon plays an irreplaceable role in the formation of soil aggregates and aggregate structure .When land use ,tillage practices and fertilization change ,the role of aggregates and aggregate structure in soil organic carbon sequestration become more prominent .There are numerous pores existing inter-and intra-aggregates ,so aggregate pore structure is used to characterize the aggregates structure.The num-ber of pores,pore size,pore shape and spatial distribution of pores affect soil water movement ,plant root growth,soil biological activity and soil organic carbon distribution , and thereby affect soil C sequestration.This paper analyzes the relationships among water , plant roots,soil organisms and aggregate pore structure ,and the roles of these factors in the dynamics of soil organic carbon ,and outlines the deficiency of the present research.Meanwhile,it expounds the applications of different computed tomography （CT） techniques in detec-ting soil aggregate structure and corresponding data extraction method ,also discusses the effects of organic carbon stabilization by aggre-gate pore structure.In the end ,this paper points out further studies which needs be strengthened in this area .