PubMed · 2026-02-15
As permafrost thaws in the Arctic and high-altitude regions, the microbial communities living in frozen soils shift in ways that accelerate carbon release, potentially creating a runaway warming cycle. This study tracked bacteria through deep permafrost cores to show that degradation destabilizes microbial ecosystems in the upper soil layers most, amplifying greenhouse gas emissions.
Bacterial diversity decreased with depth across all five 15-meter permafrost cores, while community stability increased — meaning deeper, colder layers host fewer but more resilient microbial communities.
In the active (upper) soil layer, permafrost degradation significantly destabilized bacterial communities and strengthened the negative relationship between community stability and carbon storage, suggesting more carbon is lost as soils warm.
The permafrost layer showed no significant change in community structure along the degradation gradient, indicating the upper active layer is the primary driver of carbon feedback to climate warming.