The burial efficiency of organic carbon in the sed

Authors: Sebastian Sobek Roland Zurbrügg Ilia Ostrovsky

Publish Date: 2011/02/13

Volume: 73, Issue: 3, Pages: 355-364

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Abstract

Even though lake sediments constitute a significant longterm carbon sink studies on the regulation of carbon burial in lakes sediments have to date been surprisingly few We investigated to what degree the organic carbon OC being deposited onto the bottom of Lake Kinneret Israel is buried in the sediment at four different sites with varying degrees of oxygenation and varying supply of allochthonous particles from the River Jordan For estimation of the OC burial efficiency OC BE ie the ratio between buried and deposited OC we calculated OC burial from dated sediment cores and calculated OC deposition using three different approaches Calculation of OC deposition from sediment trapderived mass deposition rates multiplied with the OC content of surface sediment yielded OC BE values that were at odds with published values for sediments dominated by autochthonous OC sources Calculation via sediment trap data on organic matter flux collected within the Lake Kinneret monitoring program as well as calculation of OC deposition as the sum of OC burial plus OC mineralization returned fairly congruent estimates of OC BE range 10–41 but only if the sediment trap data were corrected for the proportion of resuspended particles in the traps Differences in OC BE between sites were small indicating that OC source common to all sites was a more important regulator of OC BE in Lake Kinneret than oxygen exposure or mineral particles characteristicsWe want to thank Werner Eckert and Mina Bizic for support during fieldwork and Ralf Kägi for ESEM analyses Financial support from the Swiss National Science Foundation 200020112274 is acknowledged This work was partially supported by Lake Kinneret Monitoring Program funded by the Israeli Water Commissioner and by a research grant from the Israeli Science Foundation ISF Grant 627/07 S Sobek acknowledges additional support from FORMAS the Swedish Research Council for Environment Agricultural Sciences and Spatial Planning

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