Source: AGU thrives
Increased warming in high-latitude wetlands is poised to increase the activity of methogens, or methane-producing microbes. These ecosystems are complex places, however, and outcomes are difficult to predict.
In new biochemical research considering the tectonic, climatic and environmental factors affecting the Copper River Delta in Alaska, Basar-Young et al. Seismic development and glacial meltwater have each been found to have contributed to changes in microbial metabolism, with the surprising effect of potentially reducing methane production.
The Copper River Delta in south-central Alaska has a history of large seismic events. These include, most recently, a 1964 earthquake that lifted parts of the delta up to 3.4 meters above sea level, diverting much of it from a marine environment to a freshwater one. In recent decades, increasing amounts of iron-rich glacial runoff have also begun to flow through the delta as a result of climate change.
Combining geochemical studies of sediment cores from six wetland sites in the delta with metagenomic analyzes of microbes in the cores, the authors documented a distinct shift in microbial metabolism. Although the genes for methanogenesis are still common, and organic matter is available, they found that in increasingly freshwater, iron-rich environments, the dominant sources of energy production in microbes changed to include iron cycling. have moved. Their findings are a demonstration of the ways in which large-scale geological and climate shifts can affect small-scale processes such as the dynamics of microbial communities.
Looking ahead, the researchers say that analyzing core samples of deep sediments could provide more information about how microbial dynamics have changed over time. In addition, they say, more culture-based experiments could improve understanding of the relationship between iron and organic matter within the carbon cycle. For centuries.AGU thriveshttps://doi.org/10.1029/2025AV001821, 2025).
ath Nathaniel Scarping (@nathanielscarpe), science writer
