Ecosystem metabolism in sub-Antarctic streams and rivers impacted by non-native beaver

Paper abstract: Beavers can modify the hydrology, morphology, chemistry, and biology of ecosystems, though we have limited understanding of how beaver activity alters whole-ecosystem functions. We analyzed the effect of beaver activity and beaver dams on ecosystem metabolism in sub-Antarctic streams and rivers, where beavers are a non-native species. We characterized ecosystem metabolism (gross primary production and ecosystem respiration, GPP and ER) during 1-4 days in six streams and rivers with current beaver activity and dams (active) and three streams with no dams and no beavers (abandoned). Current beaver activity enhanced metabolism; GPP and ER were higher in sites with beaver activity than in more heterotrophic, abandoned sites. Beavers affect whole-ecosystem metabolism despite no detectable effects on physical and chemical variables in sub-Antarctic streams and rivers.