Winter respiration of allochthonous and autochthonous organic carbon in a subarctic clear‐water lake

• DOI: 10.4319/lo.2008.53.3.0948
• Publication Date: 2010-11-16T08:10:27Z
• Authors: Jan Karlsson; Jenny Ask; Mats Jansson
• Keywords: Subarctic climate

We studied a small subarctic lake to assess the magnitude of winter respiration and organic carbon (OC) source for this respiration. The concentration stable isotopic composition (δ 13 C) dissolved inorganic (DIC) accumulating in water under ice was analyzed over one (7 months). DIC increased δ C decreased time, with greatest changes at bottom. Winter 26% annual lake. Keeling plot analysis demonstrated that respired varied spatially, high values occurring shallow (2.5 m, 221.7‰%) compared intermediate (4 225.1‰) deep (6 227.8‰) locations variation related sediments between locations, suggesting sediment OC supported much dominant from benthic algae settled OC, predominately terrestrial origin, locations. constituted 55% respiration, equaling 54% primary production by previous summer. study indicates importance temporal spatial metabolism net unproductive high‐latitude lakes; both allochthonous autochthonous can contribute accumulation and, consequently, spring CO 2 emissions lakes.