 |
| Titel |
Effects of historical changes in land-use, N fertiliser application and atmospheric N deposition on terrestrial carbon and nitrogen fluxes |
| VerfasserIn |
Sönke Zaehle, Pierre Friedlingstein, Andrew D. Friend, Vincent Prieur, Michael Schulz |
| Konferenz |
EGU General Assembly 2010
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250039728
|
|
|
|
|
|
| Zusammenfassung |
| We present a first estimate of the consequences of historical anthropogenic perturbations of
the terrestrial carbon and nitrogen balances, in particular the emission of climatically relevant
biogenic nitrogen trace gases (NO, N2O) due to land-use changes, increases in N fertiliser
application and atmospheric deposition of reactive nitrogen. These changes are evaluated
relative to a baseline simulation taking historical climatic changes and increases in
atmospheric CO2 concentrations into account. The estimates are obtained using the global,
process-based terrestrial ecosystem model O-CN, which encodes a mechanistic
understanding of the coupling between terrestrial C and N dynamics for twelve global
vegetation types. In particular, O-CN estimates N trace gas emissions using a process-based
approach. Evaluation exercises show that the simulated effect of N additions on vegetation
productivity and net C storage agrees well with observations from a range of field
studies and manipulation experiments. N trace gas emissions fall well within the
observed ranges for individual vegetation types and global biomes, however, site-scale
analyses reveal model deficiencies in capturing the temporal dynamics of NO and
N2O emissions. Based on our global modelling results we identify key important
processes and regions for which further observations, as well as model development
and validation work are required to provide a comprehensive assessment of the
effect of anthropogenic activities on nitrogen controlled greenhouse gas balances. |
|
|
|
|
|
|