 |
| Titel |
Seasonal contribution of terrestrial organic matter and biological oxygen demand to the Baltic Sea from three contrasting river catchments |
| VerfasserIn |
H. E. Reader, C. A. Stedmon, E. S. Kritzberg |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 11, no. 12 ; Nr. 11, no. 12 (2014-06-27), S.3409-3419 |
| Datensatznummer |
250117483
|
| Publikation (Nr.) |
 copernicus.org/bg-11-3409-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
| To examine the potential influence of terrestrially derived DOM on the Baltic
Sea, a year-long study of dissolved organic matter (DOM) was performed in
three river catchments in Sweden. One catchment drains into the Bothnian Sea,
while two southern catchments drain into the Baltic proper. Dissolved organic
carbon (DOC) concentrations were positively correlated with discharge from
forested catchments over the year. While the overall concentrations of DOC
were several times higher in the southern two catchments, higher discharge in
the northern catchment resulted in the annual loadings of DOC being on the
same order of magnitude for all three catchments. Biological oxygen demand
(BOD) was used as a proxy for the lability of carbon in the system. The range
of BOD values was similar for all three catchments, however, the ratio of BOD
to DOC (an indication of the labile fraction) in Ume river was four times
higher than in the southern two catchments. Total annual BOD loading to the
Baltic Sea was twice as high in the northern catchment than in the two
southern catchments. Lower winter temperatures and preservation of organic
matter in the northern catchment combined with an intense spring flood help
to explain the higher concentrations of labile carbon in the northern
catchment. Lower lability of DOM as well as higher colour in the southern
catchments suggest that wetlands (i.e. peat bogs) may be the dominant source
of DOM in these catchments, particularly in periods of low flow. With climate
change expected to increase precipitation events and temperatures across the
region, the supply and quality of DOM delivered to the Baltic Sea can also be
expected to change. Our results indicate that DOM supply to the Baltic Sea
from boreal rivers will be more stable throughout the year, and potentially
have a lower bioavailability. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|