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Constrained microbial processing of allochthonous organic carbon in boreal lake sediments
Author(s) -
Gudasz Cristian,
Bastviken David,
Premke Katrin,
Steger Kristin,
Tranvik Lars J.
Publication year - 2012
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.2012.57.1.0163
Subject(s) - sediment , total organic carbon , environmental science , dissolved organic carbon , carbon cycle , environmental chemistry , mineralization (soil science) , microbial metabolism , organic matter , carbon fibers , carbon sink , biomass (ecology) , ecosystem , ecology , geology , chemistry , biology , soil science , bacteria , soil water , geomorphology , paleontology , materials science , composite number , composite material
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 seasonally and along a lake depth gradient in lakes with different water and sediment characteristics. Sediment bacterial metabolism was primarily controlled by temperature but also by the quality and origin of organic carbon. 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 terrestrial organic carbon influence does not result in enhanced sediment bacterial metabolism. The role of allochthonous organic carbon as the main driver of sediment bacterial metabolism suggested so far is contrary to our findings. Meio‐ and macrobenthic invertebrate biomass were, at most, weakly correlated to bacterial metabolism and biomass, suggesting limited control of sediment bacteria by grazing. 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.