Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, PR China.
Sci Total Environ. 2018 Dec 10;644:1286-1291. doi: 10.1016/j.scitotenv.2018.07.055. Epub 2018 Jul 13.
Microbial residues play important role in regulating soil carbon (C) turnover and stability, but the responses of microbial residues to climate change are neglected. In this study, a 5-year field experiment that simulated two climate change factors (precipitation and warming) was performed to examine microbial residue changes in a semiarid grassland, with water limitation. Both the contents of total amino sugars (a biomarker of microbial residues) and glucosamine (a biomarker of fungal residues) increased significantly with increased precipitation and decreased under warming, whereas neither increased precipitation nor warming influenced the content of muramic acid (a biomarker of bacterial residues). These findings clarified the role of fungal residues in determining the response of microbial residues to altered water availability and plant productivity induced by increased precipitation and elevated temperature. Interestingly, microbial residues had a much greater response to climate change than total soil C, implying that soil C composition and stability altered prior to soil C storage and simultaneously slowed down the change of soil C pool. Integrating microbial residues into current climate-C models is expected to enable the models to more accurately evaluate soil C responses to climate regimes in semiarid grasslands.
微生物残体在调节土壤碳（C）周转和稳定性方面发挥着重要作用，但微生物残体对气候变化的响应却被忽视了。本研究通过 5 年的野外实验，模拟了两种气候变化因素（降水和增温），研究了半干旱草地中水分限制条件下微生物残体的变化。总氨基糖（微生物残体的生物标志物）和氨基葡萄糖（真菌残体的生物标志物）的含量均随降水增加而显著增加，而在增温条件下则减少，而增加降水和增温均不影响 muramic acid（细菌残体的生物标志物）的含量。这些发现阐明了真菌残体在决定微生物残体对降水增加和温度升高引起的水分有效性和植物生产力变化的响应中的作用。有趣的是，微生物残体对气候变化的响应比总土壤 C 大得多，这意味着土壤 C 组成和稳定性在土壤 C 储存之前发生了变化，同时减缓了土壤 C 库的变化。将微生物残体纳入当前的气候- C 模型中，有望使模型更准确地评估半干旱草地土壤 C 对气候模式的响应。
