 |
| Titel |
Improving the dynamics of Northern Hemisphere high-latitude vegetation in the ORCHIDEE ecosystem model |
| VerfasserIn |
D. Zhu, S. S. Peng, P. Ciais, N. Viovy, A. Druel, M. Kageyama, G. Krinner, P. Peylin, C. Ottlé, S. L. Piao, B. Poulter, D. Schepaschenko, A. Shvidenko |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1991-959X
|
| Digitales Dokument |
URL |
| Erschienen |
In: Geoscientific Model Development ; 8, no. 7 ; Nr. 8, no. 7 (2015-07-28), S.2263-2283 |
| Datensatznummer |
250116464
|
| Publikation (Nr.) |
 copernicus.org/gmd-8-2263-2015.pdf |
|
|
|
|
|
| Zusammenfassung |
| Processes that describe the distribution of vegetation and ecosystem
succession after disturbance are an important component of dynamic global
vegetation models (DGVMs). The vegetation dynamics module (ORC-VD) within
the process-based ecosystem model ORCHIDEE (Organizing Carbon and Hydrology
in Dynamic Ecosystems) has not been updated and evaluated since many years
and is known to produce unrealistic results. This study presents a new
parameterization of ORC-VD for mid- to high-latitude regions in the Northern
Hemisphere, including processes that influence the existence, mortality and
competition between tree functional types. A new set of metrics is also
proposed to quantify the performance of ORC-VD, using up to five different
data sets of satellite land cover, forest biomass from remote sensing and
inventories, a data-driven estimate of gross primary productivity (GPP) and
two gridded data sets of soil organic carbon content. The scoring of ORC-VD
derived from these metrics integrates uncertainties in the observational
data sets. This multi-data set evaluation framework is a generic method that
could be applied to the evaluation of other DGVM models. The results of the
original ORC-VD published in 2005 for mid- to high-latitudes and of the new
parameterization are evaluated against the above-described data sets.
Significant improvements were found in the modeling of the distribution of
tree functional types north of 40° N. Three additional sensitivity
runs were carried out to separate the impact of different processes or
drivers on simulated vegetation distribution, including soil freezing which
limits net primary production through soil moisture availability in the root
zone, elevated CO2 concentration since 1850, and the effects of
frequency and severity of extreme cold events during the spin-up phase of
the model. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|