摘要:土壤微生物碳素利用效率（CUE）是指微生物将吸收的碳（C）转化为自身生物量C的效率，也称为微生物的生长效率。土壤微生物CUE是生态系统C循环中的重要生理生态学参数，影响着生态系统的C固持、周转、土壤矿化以及温室气体排放等过程。在全球环境变化背景下，认识土壤微生物CUE的变异及其影响机制，对于更好的认识生态系统C循环过程及其对全球变化的响应具有重要意义。概述了CUE的定义及其测定方法，重点综述和分析土壤微生物CUE的变异及影响因素取得的研究进展。基于现有研究的分析得出，土壤微生物CUE通常表示为微生物的生长与吸收的比值，分为基于微生物生长速率、微生物生物量、底物吸收速率和底物浓度变化等方法进行测定。土壤微生物CUE在0.2-0.8的范围内变化，这种变异主要受到来自热力学、生态环境因子、底物养分质量和有效性、化学计量平衡以及微生物群落组成的影响。今后土壤微生物CUE的研究应加强对微量代谢组分的定量分析，生物和环境要素交互影响的调控机理解析，以及微生物动态生理响应过程的碳循环模型优化。



Abstract:Soil microbial carbon use efficiency (CUE), also known as microbial growth efficiency, is the efficiency of microorganisms to convert carbon absorbed into biomass. It is a key ecophysiological parameter for regulating soil carbon sequestration and turnover, carbon mineralization, and greenhouse gas emissions. Knowledge on the variations and controlling mechanisms of soil microbial CUE is important to understand the soil C cycle and its response to global changes. In this study, we clarified the concept and measurements of the soil microbial CUE, and summarized the advances in the fields of its variations and influencing factors. Based on those results, we found that soil microbial CUE was generally expressed as the ratio of microbial growth to uptake, and measured by the change of microbial growth rate, biomass, substrate uptake rate or substrate concentration. The soil microbial CUE varied greatly in the range of 0.2-0.8 rather than a constant. The variations were attributed to thermodynamic constraint, environmental condition, nutrient quality and availability, stoichiometric control and microbial community composition. Future research on soil microbial CUE should focus on the quantification of neglected metabolic components, exploration of the interactive effects of the biological and abiotic factors, and integration of the dynamic physiological responses of microorganisms into soil C cycle models.





PDF全文下载地址:

https://www.ecologica.cn/stxb/article/pdf/stxb201811082427