 |
| Titel |
Lateral carbon fluxes and CO2 outgassing from a tropical peat-draining river |
| VerfasserIn |
D. Müller, T. Warneke, T. Rixen, M. Müller, S. Jamahari, N. Denis, A. Mujahid, J. Notholt |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 12, no. 20 ; Nr. 12, no. 20 (2015-10-21), S.5967-5979 |
| Datensatznummer |
250118131
|
| Publikation (Nr.) |
 copernicus.org/bg-12-5967-2015.pdf |
|
|
|
|
|
| Zusammenfassung |
| Tropical peatlands play an important role in the global carbon cycle
due to their immense carbon storage capacity. However, pristine
peat swamp forests are vanishing due to deforestation and peatland
degradation, especially in Southeast Asia. CO2 emissions
associated with this land use change might not only come from the
peat soil directly but also from peat-draining rivers. So far,
though, this has been mere speculation, since there has been no data from
undisturbed reference sites. We present the first combined
assessment of lateral organic carbon fluxes and CO2
outgassing from an undisturbed tropical peat-draining river. Two
sampling campaigns were undertaken on the Maludam River in Sarawak,
Malaysia. The river catchment is covered by protected peat swamp
forest, offering a unique opportunity to study a peat-draining river
in its natural state, without any influence from tributaries with
different characteristics. The two campaigns yielded consistent
results. Dissolved organic carbon (DOC) concentrations ranged
between 3222 and 6218 μmol L−1 and accounted for
more than 99 % of the total organic carbon (TOC). Radiocarbon
dating revealed that the riverine DOC was of recent origin,
suggesting that it derives from the top soil layers and surface
runoff. We observed strong oxygen depletion, implying high rates of
organic matter decomposition and consequently CO2
production. The measured median pCO2 was 7795 and
8400 μatm during the first and second campaign, respectively.
Overall, we found that only 32 ± 19 % of the carbon was
exported by CO2 evasion, while the rest was exported by
discharge. CO2 outgassing seemed to be moderated by the
short water residence time. Since most Southeast Asian peatlands are
located at the coast, this is probably an important limiting factor
for CO2 outgassing from most of its peat-draining rivers. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|