 |
| Titel |
Soil biogenic emissions of nitric oxide from a semi-arid savanna in South Africa |
| VerfasserIn |
G. T. Feig, B. Mamtimin, F. X. Meixner |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 5, no. 6 ; Nr. 5, no. 6 (2008-12-12), S.1723-1738 |
| Datensatznummer |
250002936
|
| Publikation (Nr.) |
 copernicus.org/bg-5-1723-2008.pdf |
|
|
|
|
|
| Zusammenfassung |
| Soils of arid and semi-arid ecosystems are important biogenic sources of
atmospheric nitric oxide (NO), however, there is still a shortage of measurements from
these systems. Here we present the results of a laboratory study of the biogenic
emission of NO from four different landscape positions of the Kruger National Park
(KNP), a large conservation area in a semi-arid region of South Africa. Results show
that the highest net potential NO fluxes come from the low lying (footslope)
landscape regions, which have the largest nitrogen stocks and highest rates of
nitrogen input into the soil. Net potential NO fluxes from midslope and crest regions were
considerably lower. The maximum release of NO occurred at fairly low soil moisture
contents of 10%–20% water filled pore space. Using soil moisture and temperature
data obtained in situ at the Kruger National Park flux tower site, net potential NO
fluxes obtained in the laboratory were converted to field fluxes for each of the
four landscape positions for the period 2003 to 2005. The highest field NO flux
is from footslope positions, during each of these years and emissions ranged from
1.5–8.5 kg ha a (in terms of mass of nitrogen). Remote sensing and Geographic
Information Systems techniques were used to up-scale field NO fluxes on a regional basis
indicating that the highest emissions occurred from the midslope positions,
due to their large geographical extent in the considered research area. Emissions
for the KNP Skukuza land type (56 000 ha) ranged from 20×103 kg in 2004 to 34×103 kg in
2003. The importance of landscape characteristics in the determination of regional
biogenic NO soil emission is emphasized. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|