Microbial lipid and amino sugar responses to long-term simulated global environmental changes in a California annual grassland.
Microbial lipid and amino sugar responses to long-term simulated global environmental changes in a California annual grassland.
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DOI：
10.3389/fmicb.2015.00385
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发表时间：
2015
影响因子：
5.2
通讯作者：
Balser TC
中科院分区：
文献类型：
--
作者：
Liang C;Gutknecht JL;Balser TC
预计全球环境变化将对碳循环和土壤生态系统的功能产生重大影响。然而，我们对它对微生物的影响了解有限，微生物在土壤中封存的碳与释放到大气中的碳之间起着“阀门”的作用。在这项研究中，我们研究了微生物连续9年操纵三个全球变化因素（升高CO2，变暖，氮沉降），单独和组合使用两种方法：脂质和氨基糖生物标志物在碧玉岭全球变化实验（JRGCE）。这两种方法产生了重要的区别。微生物脂质差异有限，但微生物氨基糖有许多显著影响。我们发现，CO2是不是一个直接影响土壤碳和主要氨基糖库的因素，但细菌源胞壁酸有积极的影响。同样，变暖和氮沉降似乎丰富的残留物特定于细菌，尽管总氨基糖的整体耗尽。结果表明，CO2浓度升高，变暖，氮沉降都出现增加细菌衍生的残留物，但这种积累效应远远抵消了真菌残留物的相应下降。微生物残留生物标志物氨基糖对变暖和氮沉降的敏感性可能对我们预测全球变化对土壤碳储存的影响有影响。
Global environmental change is predicted to have major consequences for carbon cycling and the functioning of soil ecosystems. However, we have limited knowledge about its impacts on the microorganisms, which act as a “valve” between carbon sequestered in soils versus released into the atmosphere. In this study we examined microbial response to continuous 9-years manipulation of three global change factors (elevated CO2, warming, and nitrogen deposition), singly and in combination using two methods: lipid and amino sugar biomarkers at the Jasper Ridge Global Change Experiment (JRGCE). The two methods yielded important distinctions. There were limited microbial lipid differences, but many significant effects for microbial amino sugars. We found that CO2 was not a direct factor influencing soil carbon and major amino sugar pools, but had a positive impact on bacterial-derived muramic acid. Likewise, warming and nitrogen deposition appeared to enrich residues specific to bacteria despite an overall depletion in total amino sugars. The results indicate that elevated CO2, warming, and nitrogen deposition all appeared to increase bacterial-derived residues, but this accumulation effect was far offset by a corresponding decline in fungal residues. The sensitivity of microbial residue biomarker amino sugars to warming and nitrogen deposition may have implications for our predictions of global change impacts on soil stored carbon.