E 2008, by the American Society of Limnology and Oceanography, Inc. Carbon and nitrogen loss rates during aging of lake sediment: Changes over 27 years studied in varved lake sediment
We used a collection of ten freeze cores of annually laminated (varved) lake sediment from Nylandssjön in northern Sweden collected from 1979 to 2007 to follow the long-term loss of carbon (C) and nitrogen (N) due to processes that occur in the lake bottom as sediment ages. We compared specific year...
| Main Authors: | , , , , |
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.297.3686 http://www.aslo.org/lo/toc/vol_53/issue_3/1076.pdf |
| Summary: | We used a collection of ten freeze cores of annually laminated (varved) lake sediment from Nylandssjön in northern Sweden collected from 1979 to 2007 to follow the long-term loss of carbon (C) and nitrogen (N) due to processes that occur in the lake bottom as sediment ages. We compared specific years in the different cores. For example, the loss of C from the surface varve of the 1979 core (sediment deposited during 1978) was followed in the cores from 1980, 1985, 1989, and so on until 2006. The C concentration of the sediment decreased by 20 % and N decreased by 30 % within the first five years after deposition, and after 27 yr in the sediment, there was a 23% loss of C and 35 % loss of N. Because the relative loss of C with time was smaller than loss of N, the C: N ratio increased with increasing age of the sediment; the surface varves start with a ratio of,10, which then increases to,12. Knowledge of carbon (C) and nitrogen (N) turnover and sequestration in lake sediment is important for a number of reasons, including lake management related to eutrophication, C budgets related to global warming, and, for paleolimnology to improve understanding of sediment deposits as archives for inference of past environmental conditions. Early sedimentary diagenesis has been studied in laboratory incubation experiments on freshwater algae |
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