摘要
灌木是土壤生态系统中重要的组成部分,因为它们涉及土壤排放和消纳大气CO_(2)的多个生物化学过程.本文综述了灌木与土壤中的微生物、矿物相互作用及其对土壤有机质(SOM)固存的贡献,以及环境因子对SOM转化的影响,并从研究方法、污染物干扰、生态效应、体系构建四个方面进行展望.结果表明:灌木根系分泌物(总糖、总氨基酸、酚类化合物)和林下动植物残体是SOM的主要来源.灌木对SOM转化的调节主要是通过与土壤微生物和土壤矿物互作实现的,包括与真菌形成互利共生的菌根体系,以及与土壤矿物形成抗分解的稳定络合物.此外,SOM的固存受到环境条件的影响,如适合灌木生长的温度、湿度、海拔均会促进SOM的积累,而微生物群落和土壤基质中失衡的化学计量关系则可能会促进矿化.然而,当前对灌木-微生物复合体系的分子转化机制的认知匮乏限制了灌木驱动土壤固碳的定量评估.因此,借助最新的技术手段评估现有的灌木-微生物体系固碳机制及局限性,明确高温、干旱、野火及新型环境污染物对灌木林下微生物行为的影响,是制定增强土壤固碳的战略计划、改善碳周转生命周期评估方法、缓解源-汇时间节点转变的迫切需要.
As an important component of soil ecosystems,shrubs affect several biochemical processes such as the emission and dissipation of CO_(2).This paper reviews the interaction between shrubs and soil microorganisms/minerals and their contribution to SOM sequestration and the influences of environmental factors on SOM transformation,and discusses research methods,contaminant interference,ecological effects,and system construction.The results show that shrub root secretions(i.e.,total sugars,total amino acids,phenolic compounds)and plant and animal residues are the main contributors to SOM.The interaction between shrubs and soil microorganisms and minerals mainly affects the SOM transformation through the formation of mycorrhizal symbiosis system with fungi and stable complexes with mineral.In addition,SOM sequestration can also be affected by environmental conditions.For example,appropriate temperature,humidity,and altitude can promote SOM accumulation.However,mineralization will be stimulated with unbalanced stoichiometric relationships between microbial communities and soil matrix.Notably,the knowledge gaps in molecular transformation mechanisms in shrub-microbe combined system limit the quantitative assessment of shrub-driven soil carbon sequestration.Therefore,it is necessary make full use of technologies to evaluate the carbon sequestration mechanisms and limitations of shrub-microorganism systems,as well as to clarify the effects of high temperature,drought,wildfire,and emerging pollutants on the microbial behavior in the shrubland.It is of great importance to the development of programs to enhance soil carbon sequestration,improve the assessment of carbon turnover life cycles,and mitigate source-sink time node shifts.
作者
周启星
侯泽林
莫凡
ZHOU Qixing;HOU Zelin;MO Fan(MOE Key Laboratory of Pollution Processes and Environmental Criteria,College of Environmental Science and Engineering,Carbon Neutrality Science Center of Nankai University,Tianjin 300350,China)
出处
《环境科学研究》
CAS
CSCD
北大核心
2023年第11期2169-2178,共10页
Research of Environmental Sciences
基金
国家自然科学基金(NSFC)-山东联合基金重点项目(No.U1906222)
国家重点研发计划项目(No.2019YFC1804104)
高等学校学科创新引智计划项目(No.T2017002)。
关键词
碳中和
生态滞留时间
气候变化
生物固碳
互利共生
carbon neutrality
ecological retention time
climate change
biological carbon
mutually beneficial symbiosis
