土壤有机碳分解温度敏感性的影响机制研究进展  

Mechanism underlying temperature sensitivity of soil organic carbon decomposition:A review

作　　者：陈浈雄 张超[1] 李全 宋新章[1] 施曼 CHEN Zhenxiong;ZHANG Chao;LI Quan;SONG Xinzhang;SHI Man(Bamboo Industry Institute,Zhejiang Agriculture and Forestry University,Hangzhou 311300,China)

机构地区：[1]浙江农林大学竹子研究院,杭州311300

出　　处：《应用生态学报》2023年第9期2575-2584,共10页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(32125027,32101493,31930075);浙江农林大学科学研究基金项目(2020FR088,2022LFR006)资助。

摘　　要：土壤有机碳(SOC)分解的温度敏感性(Q_(10))是估算土壤碳收支动态的重要指标,但其空间变异特征及影响因素仍有较大的不确定性。本研究主要从气候环境、空间地理格局、土壤理化性质、植被类型、微生物群落组成及功能、全球气候变化等方面对Q_(10)的影响进行综述,总结各因子对Q_(10)影响的一般规律,比较其在不同生态系统中的相对贡献。Q_(10)随温度和降水的增加而减少,随纬度和海拔的升高而增加。草原SOC分解的Q_(10)高于森林,针叶林和落叶林SOC分解的Q_(10)高于常绿阔叶林。土壤碳(C)质量与Q_(10)呈反比,但在有外源底物输入时,C质量假说并不总是有效,在低质量土壤中提高底物可利用性可显著提高Q_(10)。Q_(10)随土壤中r策略型微生物(变形菌门、子囊菌门)比例的增加而降低,随K策略型微生物(酸杆菌门、担子菌门)比例的增加而增加。大气CO_(2)浓度升高增加了Q_(10),而大气氮沉降降低了Q_(10)。在自然生态系统中,浅层土壤的Q_(10)主要受温度调控,深层土壤的Q_(10)主要受C质量调控。在全球变暖背景下,本研究可为完善气候-C循环耦合模型、实现“碳中和”战略提供理论支撑。Temperature sensitivity(Q_(10))of soil organic carbon(SOC)decomposition is an important index to estimate the dynamics of soil C budget.However,the spatial variation of Q_(10)and its influencing factors remain largely uncertain.In this study,we reviewed the effects of climate environment,spatial geographic pattern,soil physicochemical property,vegetation type,microbial community composition and function,and global climate change on Q_(10)to summarize the general rule of each factor influencing Q_(10)and compare the relative contribution of each factor to Q_(10)in different ecosystems.The results showed that Q_(10)decreases with the increases of temperature and precipitation,but increases with the rise of latitude and altitude.The Q_(10)value is higher in grassland than that in forest,and also in coniferous forest and deciduous forest than that in evergreen broad-leaved forest.Carbon quality is negatively correlated with Q_(10),but the C quality hypothesis is not always valid with exogenous substrate input.For example,the increment of substrate availability may significantly increase Q_(10)in low-quality soils.Q_(10)decreases with the enhanced proportion of r-strategy microorganisms(Proteobacteria and Ascomycetes),but increases with the enhanced proportion of K-strategy microorganisms(Acidobacteria and Basidiomycetes).Q_(10)increases with elevated CO,concentration,but declines with atmospheric nitrogen deposition.In natural ecosystems,Q_(10)is mainly regulated by temperature and C quality.Temperature is the main factor regulating Q_(10)in the topsoil while C quality is the main factor in deep soil.Our review provided a theoretical support to improve the coupled climate-C cycle model and achieved the C neutral strategy under global warming.

关 键 词：温度敏感性 有机碳分解 C质量 微生物 生态因子 

分 类 号：S153.6[农业科学—土壤学]