Microbial metabolic response to winter warming stabilizes soil carbon

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