麻豆淫院

Thawing permafrost is a major climate risk due to the associated release of carbon dioxide and other greenhouse gases (GHGs). However, new research by a team led by Prof. Yang Yuanhe from the Institute of Botany of the Chinese Academy of Sciences shows how microbes can stabilize soil carbon and potentially weaken the climate risk.

In a new study published in , the researchers provide compelling evidence that microbial carbon use efficiency (CUE)鈥攖he proportion of carbon uptake used for microbial growth鈥攔ises following abrupt permafrost thaw.

Using a substrate-independent ¹⁸O-tracing approach, the researchers examined how microbial CUE changes after abrupt permafrost thaw. They collected topsoil samples representing the permafrost thaw sequence鈥攊.e., the different phases of the thawing process鈥攁s well as samples from five additional thaw-affected sites on the Tibetan Plateau.

The results from both the thaw sequence and the regional sites consistently revealed that microbial CUE increased after permafrost thaw, demonstrating the generality of the finding.

Further analysis indicated that this rise in microbial CUE was largely driven by shifts in microbial community composition, including a higher fungal-to-bacterial biomass ratio and a greater prevalence of fast-growing taxa in thawed soils. Increased availability of soil phosphorus upon thawing also provided microbes with essential nutrients, thereby supporting growth and enhancing CUE.

Traditionally, abrupt permafrost thaw has been considered a major source of GHG emissions, accelerating carbon鈥揷limate feedback. However, the observed increase in microbial CUE may promote the incorporation of microbial-derived compounds into the soil, fostering the formation of stable soil carbon and potentially mitigating the intensity of carbon鈥揷limate feedback.

This study sheds light on how abrupt permafrost thaw affects microbial CUE and highlights the critical role of microbial physiology in determining the fate of permafrost carbon.