 |
| Titel |
Identifying environmental controls on vegetation greenness phenology through model–data integration |
| VerfasserIn |
M. Forkel, N. Carvalhais, S. Schaphoff, W. v. Bloh, M. Migliavacca, M. Thurner, K. Thonicke |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 11, no. 23 ; Nr. 11, no. 23 (2014-12-11), S.7025-7050 |
| Datensatznummer |
250117733
|
| Publikation (Nr.) |
 copernicus.org/bg-11-7025-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
| Existing dynamic global vegetation models (DGVMs) have a limited ability in
reproducing phenology and decadal dynamics of vegetation greenness as
observed by satellites. These limitations in reproducing observations
reflect a poor understanding and description of the environmental controls
on phenology, which strongly influence the ability to simulate longer-term
vegetation dynamics, e.g. carbon allocation. Combining DGVMs with
observational data sets can potentially help to revise current modelling
approaches and thus enhance the understanding of processes that control
seasonal to long-term vegetation greenness dynamics. Here we implemented a
new phenology model within the LPJmL (Lund Potsdam Jena managed lands) DGVM
and integrated several observational data sets to improve the ability of the
model in reproducing satellite-derived time series of vegetation greenness.
Specifically, we optimized LPJmL parameters against observational time
series of the fraction of absorbed photosynthetic active radiation (FAPAR),
albedo and gross primary production to identify the main environmental
controls for seasonal vegetation greenness dynamics. We demonstrated that
LPJmL with new phenology and optimized parameters better reproduces
seasonality, inter-annual variability and trends of vegetation greenness.
Our results indicate that soil water availability is an important control on
vegetation phenology not only in water-limited biomes but also in boreal
forests and the Arctic tundra. Whereas water availability controls phenology
in water-limited ecosystems during the entire growing season, water
availability co-modulates jointly with temperature the beginning of the
growing season in boreal and Arctic regions. Additionally, water
availability contributes to better explain decadal greening trends in the
Sahel and browning trends in boreal forests. These results emphasize the
importance of considering water availability in a new generation of
phenology modules in DGVMs in order to correctly reproduce observed seasonal-to-decadal dynamics of vegetation greenness. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|