Microbial metabolic response to winter warming stabilizes soil carbon

A - Papers appearing in refereed journals

Tian, J., Zong, N., Harley, I. P., He, N., Zhang, J., Powlson, D. S., Zhou, J., Kuzyakov, Y., Zhang, F., Yu, G. and Dungait, J. A. J. 2021. Microbial metabolic response to winter warming stabilizes soil carbon. Global Change Biology. https://doi.org/10.1111/gcb.15538

AuthorsTian, J., Zong, N., Harley, I. P., He, N., Zhang, J., Powlson, D. S., Zhou, J., Kuzyakov, Y., Zhang, F., Yu, G. and Dungait, J. A. J.
Abstract

Current consensus on global climate change predicts warming trends with more pronounced temperature changes in winter than summer in the Northern Hemisphere at high latitudes. Moderate increases in soil temperature are generally related to faster rates of soil organic carbon (SOC) decomposition in Northern ecosystems, but there is evidence that SOC stocks have remained remarkably stable or even increased on the Tibetan Plateau under these conditions. This intriguing observation points to altered soil microbial mediation of carbon‐cycling feedbacks in this region that might be related to seasonal warming. This study investigated the unexplained SOC stabilization observed on the Tibetan Plateau by quantifying microbial responses to experimental seasonal warming in a typical alpine meadow. Ecosystem respiration was reduced by 17%–38% under winter warming compared with year‐round warming or no warming and coincided with decreased abundances of fungi and functional genes that control labile and stable organic carbon decomposition. Compared with year‐round warming, winter warming slowed macroaggregate turnover rates by 1.6 times, increased fine intra‐aggregate particulate organic matter content by 75%, and increased carbon stabilized in microaggregates within stable macroaggregates by 56%. Larger bacterial “necromass” (amino sugars) concentrations in soil under winter warming coincided with a 12% increase in carboxyl‐C. These results indicate the enhanced physical preservation of SOC under winter warming and emphasize the role of soil microorganisms in aggregate life cycles. In summary, the divergent responses of SOC persistence in soils exposed to winter warming compared to year‐round warming are explained by the slowing of microbial decomposition but increasing physical protection of microbially derived organic compounds. Consequently, the soil microbial response to winter warming on the Tibetan Plateau may cause negative feedbacks to global climate change and should be considered in Earth system models.

KeywordsCarbon degradation genes; Microbial anabolism; Microbial community; SOC stabilization; Soil aggregate turnover; Winter warming
Year of Publication2021
JournalGlobal Change Biology
Digital Object Identifier (DOI)https://doi.org/10.1111/gcb.15538
Open accessPublished as bronze (free) open access
FunderBiotechnology and Biological Sciences Research Council
National Natural Science Foundation of China
National Key Research and Development Program of China
Funder project or codeS2N - Soil to Nutrition [ISPG]
Publisher's version
Output statusPublished
Publication dates
Online13 Feb 2021
Publication process dates
Accepted02 Feb 2021
PublisherWiley
ISSN1354-1013

Permalink - https://repository.rothamsted.ac.uk/item/98377/microbial-metabolic-response-to-winter-warming-stabilizes-soil-carbon

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