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| Titel |
Post-disturbance dynamics in forest-atmosphere fluxes: Observations from a windthrow site in the European Alps |
| VerfasserIn |
Bradley Matthews, Mathias Mayer, Klaus Katzensteiner, Helmut Schume |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250111775
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| Publikation (Nr.) |
 EGU/EGU2015-11917.pdf |
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| Zusammenfassung |
| Natural disturbances can cause abrupt and substantial changes in ecosystem properties
regulating forest-atmosphere exchange. Although forest sites disturbed by e.g. wind, fire, and
insects have become important targets of micrometeorological research, investigations of
intact and disturbed forests in mountainous areas remain comparatively scarce. This
discrepancy is likely explained by the additional methodological challenges posed by
mountainous ecosystems, especially with respect to the eddy covariance technique.
Nonetheless, the lack of such experiments constitutes a significant void in global and regional
flux networks, particularly in the Central European context, where the Alps are forecasted as
potential hotspots of intensifying windthrow and bark beetle disturbance regimes. We
therefore began a micrometeorological investigation at a forest site in the Northern
Calcareous Alps of Austria disturbed by windthrow and subsequent bark beetle infestation in
2009. The objectives of the study were to determine 1) whether the eddy covariance
technique provides robust measurements of turbulent surface-atmosphere exchange at
the site and 2) how net exchange of carbon dioxide (CO2), water vapor, sensible
heat and shortwave radiation develop over 3 subsequent growing seasons (2011 to
2013) following disturbance. According to a flux quality assessment looking at
turbulence, stationarity, flux footprint and energy balance closure, eddy covariance
provides defensible estimates of net turbulent exchange at the site, despite the non
ideal conditions for its application. While the site remained a CO2 source in 2013,
decreasing net CO2 release over the three subsequent growing seasons indicated that the
ecosystem was in a state of recovery. Moreover, it appeared that this recovery also
significantly influenced the net exchange of shortwave radiation and the partitioning
between sensible and latent heat fluxes. Taking into account the varying climate over
the three campaign seasons, the results suggest a slight increase in the shortwave
albedo and a decrease in bowen ratio over this initial period following disturbance.
This study was funded by the European Regional Development Fund (ERDF). |
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