 |
| Titel |
Partitioning of catchment water budget and its implications for ecosystem carbon exchange |
| VerfasserIn |
D. Lee, J. Kim, K.-S. Lee, S. Kim |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 7, no. 6 ; Nr. 7, no. 6 (2010-06-14), S.1903-1914 |
| Datensatznummer |
250004844
|
| Publikation (Nr.) |
 copernicus.org/bg-7-1903-2010.pdf |
|
|
|
|
|
| Zusammenfassung |
| Spatially averaged annual carbon budget is one of the key information needed
to understand ecosystem response and feedback to climate change. Water
availability is a primary constraint of carbon uptake in many ecosystems and
therefore the estimation of ecosystem water use may serve as an alternative
to quantify Gross Primary Productivity (GPP). To examine this concept, we
estimated a long-term steady state water budget for the Han River basin
(~26 000 km2) in Korea and examined its application for catchment
scale carbon exchange. For this, the catchment scale evapotranspiration
(ET) was derived from the long term precipitation (P) and discharge (Q) data.
Then, using stable isotope data of P and Q along with other
hydrometeorological information, ET was partitioned into evaporation from soil
and water surfaces (ES), evaporation from intercepted rainfall
(EI, and transpiration (T). ES was identified as a minor component
of ET in the study areas regardless of the catchment scales. The annual T,
estimated from ET after accounting for EI and ES for the Han River
basin from 1966 to 2007, was 22~31% of annual P and the proportion
decreased with increasing P. Assuming that T further constrains the catchment
scale GPP in terms of water use efficiency (WUE), we examined the possibility of
using T as a relative measure for the strength and temporal changes of carbon
uptake capacity. The proposed relationship would provide a simple and
practical way to assess the spatial distribution of ecosystem GPP, provided the
WUE estimates in terms of GPP/T at ecosystem scale could be obtained. For carbon
and water tracking toward a sustainable Asia, ascertaining such a
spatiotemporally representative WUE and their variability is a requisite facing
the flux measurement and modeling communities. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|