|Title||Role of a productive lake in carbon sequestration within a calcareous catchment.|
|Publication Type||Journal Article|
|Year of Publication||2016|
|Authors||Nõges P, Cremona F, Laas A, Martma T, Rõõm E-I, Toming K, Viik M, Vilbaste S, Noges T|
|Journal||Science of the Total Environment|
For a long time, lakes were considered unimportant in the global carbon (C) cycle because of their small total area compared to the ocean. Over the last two decades, a number of studies have highlighted the important role of lakes in both sequestering atmospheric C and modifying the C flux from the catchment by degassing CO2 and methane and burying calcite and organic matter in the sediment. Based on a full C mass balance, high frequency measurements of lake metabolism and stable isotope analysis of a large shallow eutrophic lake in Estonia, we assess the role alkaline lakes play in augmenting the strength of terrestrial carbonate weathering as a temporary CO2 sink. We show that a large part of organic C buried in the sediments in this type of lakes originates from the catchment although a direct uptake from the atmosphere during periods of intensive phytoplankton growth in eutrophic conditions contributes to the carbon sink.