Beaver Wetlands Store Carbon at Nearly Ten Times the Rate of Unmodified Streams

A research article released on March 18 in Communications Earth and Environment reveals that Eurasian beavers in Switzerland are converting stream corridors into effective carbon sinks. The study, led by Lukas Hallberg from the University of Birmingham, focused on a beaver-created wetland in the Rhine River basin in northern Switzerland. Data on water flow, dissolved carbon, plant growth, and greenhouse gas emissions were gathered from January 2022 to January 2023. The wetland sequestered nearly 100 net tons of carbon annually, accumulating around 1,100 net tons over 13 years—comparable to two Olympic swimming pools filled with charcoal. Even in dry summer months, carbon storage exceeded emissions, with minimal methane release. Beaver dams help slow water flow, enabling sediment deposition and carbon absorption by wetland vegetation. The team suggests that beaver wetlands could sequester carbon at rates nearly ten times greater than similar areas without beavers. In suitable Swiss land, beavers might offset 1.2 to 1.8 percent of the nation's annual carbon emissions. While the study examined only one site, carbon storage rates differ across locations. Once nearly extinct due to overhunting by the early 20th century, Eurasian beavers have rebounded to approximately 1.5 million mature individuals throughout Europe.