Constrained microbial processing of allochthonous organic carbon in boreal lake sediments
2012 (English)In: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 57, no 1, 163-175 p.Article in journal (Refereed) Published
We investigated sediment bacterial metabolism in eight lakes with different inputs of allochthonous and autochthonous organic carbon in south-central Sweden. Sediment bacterial production, mineralization and biomass were measured on a seasonal basis and along a lake depth gradient together with different water and sediment characteristics. Sediment bacterial metabolism was primarily controlled by temperature but also regulated by organic carbon quality/origin. Metabolism was positively correlated to measures of autochthonous influence on the sediment organic carbon, but did not show a similar increase with increasing input of allochthonous organic carbon. Hence, in contrast to what is currently known for the water column, increasing amounts of terrestrial organic carbon do not result in enhanced sediment bacterial metabolism. Meio- and macrobenthic invertebrate biomass were at most weakly correlated to bacterial metabolism and biomass, suggesting limited control of sediment bacteria by grazing. We suggest that the bacterial metabolism in boreal lake sediments is constrained by low temperatures and by the recalcitrant nature of the dominant organic carbon, resulting in sediments being an effective sink of organic carbon.
Place, publisher, year, edition, pages
2012. Vol. 57, no 1, 163-175 p.
allochthonous organic carbon, microbial metabolism, lake sediments
Research subject Limnology
IdentifiersURN: urn:nbn:se:uu:diva-150712DOI: 10.4319/lo.2012.57.1.0163ISI: 000298321300014OAI: oai:DiVA.org:uu-150712DiVA: diva2:408444