表土和底土中微生物残体对增温的差异性响应
作者:
作者单位:

南京信息工程大学生态与应用气象学院

中图分类号:

S154.2

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)


Differential Responses of Microbial Necromass to Warming in topsoil and subsoil
Author:
Affiliation:

School of Ecology and Applied Meteorology,Nanjing University of Information Science Technology

Fund Project:

the National Natural Science Foundation of China (No. 42477312), and the Special Technology Innovation Fund of Carbon Peak and Carbon Neutrality in Jiangsu Province (BK20231515)

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    摘要:

    微生物残体是土壤有机碳库的重要组分,探明微生物残体对气候变化的响应是深入理解微生物调控土壤有机碳形成机制的关键。目前关于气候变暖对不同生态系统中表层和底层土壤微生物残体(MNC)积累影响的普遍规律尚不清楚。本文基于已发表的同时包含表层和底层MNC对增温响应的文献数据,共8个研究样点,包括41组总氨基糖数据,69组氨基葡萄糖数据,69组胞壁酸数据和26组氨基半乳糖数据,通过Meta整合分析方法系统研究了增温对表层和底层残体积累及其对土壤有机碳(SOC)贡献的影响。结果表明:增温整体上促进MNC在不同土层中的积累,且对表层MNC积累的促进作用(14.3%)高于底层土壤(2.9%)。这可能与增温背景下不同土层中植物碳输入的差异及微生物群落的空间异质性有关。然而由于增温后底层SOC的损失加快,使得增温后底层MNC对SOC的贡献(12.5%)高于表层土壤(11.3%)。此外,增温对不同土层中真菌残体积累及其对SOC贡献的正效应大于细菌残体,说明新增碳输入直接或间接调节微生物残体的组成。不同土层MNC的积累与增温的幅度和年限密切相关。较低的增温幅度(≤ 2℃)促进微生物合成代谢使表层MNC积累的促进作用明显(17.2%),而较高的增温幅度(> 2℃)促进底层碳库积累来提高底层MNC对SOC的贡献(14.7%)。从时间尺度看,长期增温(> 5a)改变微生物活动模式使底层MNC占SOC比例更大(42.8%)。同时,森林和农田生态系统中各类残体对SOC的贡献随土层深度的增加而增加;而增温削弱了草地生态系统底层残体对SOC的贡献。综上,本文强调开展特定生态系统中微生物介导有机碳积累动态对增温响应的研究时,应同时关注表土和底土中微生物残体的响应,这对于理解和预测土壤有机碳动态对气候变化的敏感性及其反馈机制至关重要。

    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】This study conducted a meta-analysis of 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 input directly or indirectly regulated 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 (> 5a) 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, we suggest that 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.

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引用本文

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,,[待发表]
YANG Dongqiao, ZHANG Zihan, LU Mengya, DING Xueli. Differential Responses of Microbial Necromass to Warming in topsoil and subsoil[J]. Acta Pedologica Sinica,,[In Press]

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  • 收稿日期:2024-07-08
  • 最后修改日期:2024-09-24
  • 录用日期:2024-11-15
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