Glacier-fed lakes produce lower methane fluxes than non-glacier-fed lakes on the Tibetan Plateau

Abstract Glacial lakes in high-altitude regions influence both water systems and greenhouse gas emissions, yet the effects of different hydrological recharge mechanisms on methane release and microbial ecosystems remain poorly understood. Here, we investigated methane fluxes and microbial community patterns in glacier-fed and non-glacier-fed lakes on the Tibetan Plateau during peak ablation stage. Our findings revealed that total methane flux from non-glacier-fed lakes were approximately three times higher than from glacier-fed lakes, with ebullition being the predominant emission pathway. Network analysis showed that the microbial community structure in glacier-fed lakes was more stable. The neutral community model confirmed deterministic processes mainly shape microbial assembly in glacial lakes with different recharge types. Microbial communities in glacier-fed lakes were more stable and tightly connected, while those in non-glacier-fed lakes were more fragmented. As glacier melting accelerates with climate change, more lakes may lose glacier input, potentially increasing methane emissions and disrupting microbial ecosystems.