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| Titel |
An analysis of the decadal variability of Carbon fluxes in European forests through process-based modelling |
| VerfasserIn |
Nicolas Delpierre, Kamel Soudani, Christophe François, Christian Bernhofer, Werner Kutsch, Laurent Misson, Timo Vesala, Eric Dufrêne |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250033307
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| Zusammenfassung |
| With several sites measuring mass and energy turbulent fluxes for more than ten years, the CarboEurope database appears as a valuable resource for addressing the question of the determinism of the interannual variability of carbon (C) balance in forests ecosystems.
Apart from major climate-driven anomalies during the anomalous 2003 summer and 2007 spring, little is known about the factors driving interannual variability (IAV) of the C balance in European forests.
We used the CASTANEA process-based model to simulate the C balances of four European forests for the 2000-2007 period, spanning a large latitudinal range (44-62°N). The model fairly reproduced the day-to-day variability of measured fluxes, and accounted for 36-82% (mean=63%, n=4) of the observed interannual variance in daytime NEP.
We used CASTANEA as a tool for disentangling the influence of climate and biological drivers on C fluxes at mutiple time scales. A set of constrained simulation was performed to identify the proper effects of climate (PAR, temperature, relative humidity, soil water content) and biological drivers (canopy phenology, plant and soil C stocks) on flux variability. Their relative contributions to flux variance across timescales was quantified through orthonormal wavelet decomposition of the single-driver effects time series.
As a general feature, we observed a declining contribution of climate drivers to flux (GPP, Reco or NEP) interannual variance from daily to annual timescale. Our analyses revealed that most (40-90%, mean=70%) of the simulated NEP interannual variance at annual scale was caused by climate anomalies, with biological drivers playing a more modest role in such mature and relatively undisturbed forests.
We contrast results obtained through this novel process-based modelling approach with those arising from more classical data-mining analyses.
Keywords: Process-based model, interannual variability, Carbon balance, water balance, phenology, biological drivers, climate drivers. |
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