Thermokarst lake drainage halves the temperature sensitivity of CH<sub>4</sub> release on the Qinghai-Tibet Plateau.

Mu, Mei; Mu, Cuicui; Liu, Hebin; Lei, Pengsi; Ge, Yongqi; Zhou, Zhensong; Peng, Xiaoqing; Ma, Tian · Nat Commun · 2025

basic_science · Level V

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Abstract

Thermokarst lakes as hot spots of methane (CH<sub>4</sub>) release are crucial for predicting permafrost carbon feedback to global warming. These lakes are suffering from serious drainage events, however, the impacts of lake drainage on CH<sub>4</sub> release remain unclear. Here, synthesizing field drilling, incubation experiments, and carbon composition and microbial communities, we reveal the temperature sensitivities (Q<sub>10</sub>) and drivers of CH<sub>4</sub> release from drainage-affected lakes on the Qinghai-Tibet Plateau. We find that cumulative CH<sub>4</sub> release decreases with depth, where 0-30 cm-depth sediment accounts for 97% of the whole release. The Q<sub>10</sub> of surface sediment is 2 to 4 times higher than deep layers, but roughly 56% lower than the non-drainage lakes. The response of CH<sub>4</sub> release to warming is mainly driven by microbial communities (49.3%) and substrate availability (30.3%). Our study implies that drainage mitigates CH<sub>4</sub> release from thermokarst lakes and sheds light on crucial processes for understanding permafrost carbon projections.