 |
| Titel |
Trends in long-term carbon and water fluxes - a case study from a temperate Norway spruce site |
| VerfasserIn |
Wolfgang Babel, Johannes Lüers, Jörg Hübner, Andrei Serafimovich, Christoph Thomas, Thomas Foken |
| Konferenz |
EGU General Assembly 2016
|
| Medientyp |
Artikel
|
| Sprache |
en
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250132498
|
| Publikation (Nr.) |
 EGU/EGU2016-13010.pdf |
|
|
|
|
|
| Zusammenfassung |
| In this study we analyse eddy-covariance flux measurements of carbon dioxide and water
vapour from 18 years at Waldstein-Weidenbrunnen (DE-Bay), a Norway spruce forest site in
the Fichtelgebirge, Germany. Standard flux partitioning algorithms have been applied for
separation of net ecosystem exchange NEE into gross ecosystem uptake GEE and
ecosystem respiration Reco, and gap-filling. The annual NEE shows a positive
trend, which is related to a strong increase in GEE, while Reco enhances slightly.
Annual evapotranspiration increases as well, while atmospheric demand, i.e. potential
evapotranspiration, shows inter-annual variability, but no trend. Comparisons with studies
from other warm temperate needle-leaved forests show, that NEE is at the upper range of the
distribution, and evapotranspiration in Budyko space is in a similar range, but with a large
inter-annual variability. While this trends are generally in agreement with findings
from other locations and expectations to climate change, the specific history at this
site clearly has a large impact on the results: The forest was in the first years very
much affected due to forest decline and convalesced after a liming. In the last ten
years the site was much affected by beetles and windthrow. Thus the more recent
positive trends may be related to increased heterogeneity at the site. As FLUXNET
stations, built 10-20 years ago, often started with “ideal forest sites”, increasing
heterogeneity might be a more general problem for trend analysis of long-term data sets. |
|
|
|
|
|
|