ISSN:
1573-515X
Keywords:
humic lake
;
TOC
;
acidification
;
climate
;
carbon budget
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Geosciences
Notes:
Abstract Studies of fluctuations in total organic carbon (TOC) were performedin both the reference basin and the acidified basin of experimental LakeSkjervatjern, in order to separate effects of various catchment and in-lakeprocesses. Nearly five years of catchment acidification did not inducesignificant changes in TOC. TOC concentrations was not related clearly toprecipitation or runoff. In both basins, there was a regular, seasonal patternwith a gradual increase in TOC concentrations from spring to late autumn.Minima in concentrations occurred during periods with frozen ground inwinter, irrespective of discharge patterns. The decrease from ∼10 mg C l-1 in autumn to 1--2 mg C l-1 in latewinter, was only seen in surface layers. Runoff was the major loss routefor surface TOC in the lake. Photo-oxidation, bacterial oxidation, andsedimentation combined yielded maximum loss rates of 3%of surface TOC d-1. Below a depth of 1 m 0.5%d-1 was lost to these same processes. The surface microlayerhad 5--10 times more TOC than the bulk water on average, and could haveeffects on gas exchange and sub-surface light. Despite the oxidation ofTOC, the short residence time of the lake and rapid replacement of TOCfrom the catchment was the major determinant of lake water TOC.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1005740030477
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