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| Titel |
Effects of climate, fire and vegetation development on Holocene changes in total organic carbon concentration in three boreal forest lakes in northern Sweden |
| VerfasserIn |
P. Rosén, D. Hammarlund |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 4, no. 6 ; Nr. 4, no. 6 (2007-11-13), S.975-984 |
| Datensatznummer |
250001993
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| Publikation (Nr.) |
 copernicus.org/bg-4-975-2007.pdf |
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| Zusammenfassung |
| Near infrared spectroscopy (NIRS), diatoms, pollen, charcoal,
loss-on-ignition (LOI), and nutrient elements in lake sediments were used to
assess important factors controlling Holocene changes in the total organic
carbon (TOC) concentration, pCO2, color and pH of lake water in three
boreal forest lakes in northern Sweden. The results suggest that mire
formation, fire frequency and humidity are the most important forcing factors
on millennial timescales. Mires produce humic acids that become available to
the lakes, whereas fires may reduce the pool of carbon in the catchments, and
humidity controls the transportation of allochthonous carbon into the lakes.
Vegetation development and temperature as sole factors are of minor
importance for the TOC concentrations in these lakes on a millennial
timescale. Two of the sites indicate that liming and possibly fish
introduction and rotenone treatment in recent time has led to increased TOC,
color and pH in the lake water, and changed the diatom community composition
to an assemblage that has never been present before. Given the predicted
climate change scenario that suggests a more humid climate, expanding mires
and less frequent fires, our paleolimnological data suggest that TOC
concentrations can be expected to increase in boreal forest lakes in the
future. Since super-saturation and emission of CO2 from lakes is
correlated to the TOC concentration of lake water, higher TOC concentrations
may lead to increased emission of CO2 from lakes to the atmosphere. |
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