Research article2015Peer reviewedOpen access
Carbon dioxide evasion from headwater systems strongly contributes to the total export of carbon from a small boreal lake catchment
Kokic, Jovana; Wallin, Marcus B.; Chmiel, Hannah E.; Denfeld, Blaize A.; Sobek, Sebastian
Abstract
Inland waters are hotspots for carbon (C) cycling and therefore important for landscape C budgets. Small streams and lakes are particularly important; however, quantifying C fluxes is difficult and has rarely been done for the entire aquatic continuum, composed of connected streams and lakes within the same catchment. We investigated carbon dioxide (CO2) evasion and fluvial fluxes of dissolved inorganic carbon and dissolved organic carbon (DIC and DOC) in stream and lake systems within the 2.3km(2) catchment of a small boreal lake. Our results show pronounced spatial and temporal variability in C fluxes even at a small spatial scale. C loss from the catchment through CO2 evasion from headwaters for the total open water-sampling period was 9.7g C m(-2) catchment, dominating the total catchment C loss (including CO2 evasion, DIC, and DOC export from the lake, which were 2.7, 0.2, and 5.2g C m(-2) catchment, respectively). Aquatic CO2 evasion was dominated by headwater streams that occupy similar to 0.1% of the catchment but contributed 65% to the total aquatic CO2 evasion from the catchment. The importance of streams was mainly an effect of the higher gas transfer velocities than compared to lakes (median, 67 and 2.2cmh(-1), respectively). Accurately estimating the contribution of C fluxes from headwater streams, particularly the temporal and spatial dynamics in their gas transfer velocity, is key to landscape-scale C budgets. This study demonstrates that CO2 evasion from headwaters can be the major pathway of C loss from boreal catchments, even at a small spatial scale.
Keywords
small lakes; streams; carbon dioxide evasion; carbon flux; gas transfer velocity
Published in
Journal of Geophysical Research: Biogeosciences
2015, Volume: 120, number: 1, pages: 13-28 Publisher: AMER GEOPHYSICAL UNION
UKÄ Subject classification
Geosciences, Multidisciplinary
Publication identifier
DOI: https://doi.org/10.1002/2014JG002706
Permanent link to this page (URI)
https://res.slu.se/id/publ/105656