Spatiotemporal variations of pCO(2) and delta C-13-DIC in subarctic streams in northern Sweden
2013 (English)In: Global Biogeochemical Cycles, ISSN 0886-6236, Vol. 27, no 1, 176-186 p.Article in journal (Refereed) Published
Current predictions of climate-related changes in high-latitude environments suggest major effects on the C export in streams and rivers. To what extent this will also affect the stream water CO2 concentrations is poorly understood. In this study we examined the spatiotemporal variation in partial pressure of CO2 (pCO(2)) and in stable isotopic composition of dissolved inorganic carbon (delta C-13-DIC) in subarctic streams in northern Sweden. The selected watersheds are characterized by large variations in high-latitude boreal forest and tundra and differences in bedrock. We found that all streams generally were supersaturated in pCO(2) with an average concentration of 850 mu atm. The variability in pCO(2) across streams was poorly related to vegetation cover, and carbonaceous bedrock influence was manifested in high DIC concentrations but not reflected in either stream pCO(2) or delta C-13-DIC. Stream water pCO(2) values were highest during winter base flow when we also observed the lowest delta C-13-DIC values, and this pattern is interpreted as a high contribution from CO2 from soil respiration. Summer base flow delta C-13-DIC values probably are more affected by in situ stream processes such as aquatic production/respiration and degassing. A challenge for further studies will be to disentangle the origin of stream water CO2 and quantify their relative importance.
Place, publisher, year, edition, pages
2013. Vol. 27, no 1, 176-186 p.
Environmental Sciences Ecology Geosciences, Multidisciplinary Meteorology and Atmospheric Sciences
IdentifiersURN: urn:nbn:se:su:diva-89539DOI: 10.1002/gbc.20024ISI: 000318275300017OAI: oai:DiVA.org:su-89539DiVA: diva2:619243
FunderSwedish Research Council, 2007-3841Swedish Research Council, 2009-2999Formas, 214-2008-202