土壤学报2026，Vol.63Issue(1)：315-328,14.DOI:10.11766/trxb202407080274
表土和底土中微生物残体对增温的差异性响应
Differential Responses of Microbial Necromass to Warming in Topsoil and Subsoil
摘要
Abstract
[Objective]Microbial necromass carbon(MNC)is an important component of the soil organic carbon(SOC)pool and probing the response of MNC to climate change is key to a deeper understanding of the mechanisms of microbial-mediated regulation of SOC formation.There is still a lack of understanding regarding the impact of climate warming on topsoil and subsoil MNC accumulation dynamics in different ecosystems.[Method]A meta-analysis was conducted to investigate the effect of warming of 8 sample sites on MNC in different soil layers and its contribution to SOC and on the response of topsoil and subsoil MNC to warming(41 for total amino sugars,69 for glucosamine,69 for muramic acid and 26 for galactosamine).[Result]Warming promoted the accumulation of MNC in different soil layers as a whole,especially in the topsoil(14.3%).This may be related to the differences in plant-carbon input and the spatial heterogeneity of microbial communities in different soil layers under a warming background.However,due to the acceleration of the loss of SOC in the subsoil after warming,the proportion of MNC contribution to SOC in the subsoil(12.5%)was higher than that in the topsoil(11.3%).Furthermore,the positive effect of the accumulation of fungal necromass and their contribution to SOC in different soil layers was greater than that of bacterial necromass,suggesting that the new carbon imput directly or indirectly regulat the composition of MNC.Moreover,the impact of warming on the accumulation of MNC in different soil layers is bound up with warming amplitude and years.Lower warming(≤2℃)promoted microbial anabolism to increase the accumulation of MNC in the topsoil by 17.2%,while the contribution of MNC in increasing SOC in the subsoil pool was significantly promoted(14.7%)during higher warming(>2℃).On the timescale of warming,long-term warming(>5 a)changed the microbial activity pattern and had a greater impact on the ratio of MNC to SOC in subsoil(42.8%).Meanwhile,the contribution of microbial necromass to SOC was increased with soil depth in forest and cropland,whereas warming weakened the proportion of subsoil microbial necromass to SOC in grassland.[Conclusion]Based on our analysis,it is suggested that future research on the dynamics of microbial-mediated organic carbon accumulation in specific ecosystems in response to warming should focus on the response of microbial necromass in both topsoil and subsoils.This would provide a huge boost to understanding and predicting the sensitivity of SOC dynamics to climate change and its feedback mechanisms.关键词
增温/表层土壤/底层土壤/微生物残体/土壤有机碳Key words
Warming/Topsoil/Subsoil/Microbial necromass/Soil organic carbon分类
农业科技引用本文复制引用
阳东桥,张子寒,卢孟雅,丁雪丽..表土和底土中微生物残体对增温的差异性响应[J].土壤学报,2026,63(1):315-328,14.基金项目
国家自然科学基金项目(42477312)、江苏省碳达峰碳中和科技创新专项(BK20231515)资助 Supported by the National Natural Science Foundation of China(No.42477312)and the Special Technology Innovation Fund of Carbon Peak and Carbon Neutrality in Jiangsu Province(No.BK20231515) （42477312）
