Seasonal particulate organic carbon dynamics of the Kolyma River tributaries, Siberia ...

• Main Authors: Keskitalo, Kirsi H., Bröder, Lisa, Tesi, Tommaso, Mann, Paul J., Jong, Dirk J., Bulte Garcia, Sergio, Davydova, Anna, Davydov, Sergei, Zimov, Nikita, Haghipour, Negar, Eglinton, Timothy I., Vonk, Jorien E.
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2024
• Subjects: Arctic; kolyma river; permafrost; Siberia
• Online Access: https://dx.doi.org/10.3929/ethz-b-000659602; http://hdl.handle.net/20.500.11850/659602

Arctic warming is causing permafrost thaw and release of organic carbon (OC) to fluvial systems. Permafrost-derived OC can be transported downstream and degraded into greenhouse gases that may enhance climate warming. Susceptibility of OC to decomposition depends largely upon its source and composition, which vary throughout the seasonally distinct hydrograph. Most studies on carbon dynamics to date have focused on larger Arctic rivers, yet little is known about carbon cycling in lower-order rivers and streams. Here, we characterize the composition and sources of OC, focusing on less studied particulate OC (POC), in smaller waterways within the Kolyma River watershed. Additionally, we examine how watershed characteristics control carbon concentrations. In lower-order systems, we find rapid initiation of primary production in response to warm water temperatures during spring freshet, shown by decreasing δ¹³C-POC, in contrast to larger rivers. This results in CO₂ uptake by primary producers and microbial ... : Biogeosciences, 21 (2) ...