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| Titel |
Terrestrial carbon-nitrogen interactions across time-scales |
| VerfasserIn |
Sönke Zaehle, Kerstin Sickel |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250149491
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| Publikation (Nr.) |
 EGU/EGU2017-13846.pdf |
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| Zusammenfassung |
| Through its role in forming amino acids, nitrogen (N) plays a fundamental role in terrestrial
biogeochemistry, affecting for instance the photosynthetic rate of a leaf, and the amount of
leaf area of a plant; with further consequences for quasi instantaneous terrestrial biophysical
properties and fluxes. Because of the high energy requirements of transforming atmospheric
N2 to biologically available form, N is generally thought to be limiting terrestrial
productivity. Experimental evidence and modelling studies suggest that in temperate and
boreal ecosystems, this N-"limitation" affects plant production at scales from days to decades,
and potentially beyond. Whether these interactions play a role at longer timescales, such as
during the transition from the last glacial maximum to the holocene, is currently
unclear.
To address this question, we present results from a 22000 years long simulation with
dynamic global vegetation model including a comprehensive treatment of the terrestrial
carbon and nitrogen balance and their interactions (using the OCN-DGVM) driven by
monthly, transient climate forcing obtained from the CESM climate model (TRACE). OCN
couples carbon and nitrogen processes at the time-scale of hours, but simulates a
comprehensive nitrogen balance as well as vegetation dynamics with time-scales of
centuries and beyond. We investigate in particular, whether (and at with time scale)
carbon-nitrogen interactions cause important lags in the response of the terrestrial
biosphere to changed climate, and which processes (such as altered N inputs from
fixation or altered losses through leaching and denitrification) contribute to these lags. |
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