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Titel |
Asynchronism in leaf and wood production in tropical forests: a study combining satellite and ground-based measurements |
VerfasserIn |
F. Wagner, V. Rossi, C. Stahl, D. Bonal, B. Hérault |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1726-4170
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Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 10, no. 11 ; Nr. 10, no. 11 (2013-11-14), S.7307-7321 |
Datensatznummer |
250085416
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Publikation (Nr.) |
copernicus.org/bg-10-7307-2013.pdf |
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Zusammenfassung |
The fixation of carbon in tropical forests mainly occurs through the
production of wood and leaves, both being the principal components
of net primary production. Currently field and satellite
observations are independently used to describe the forest carbon
cycle, but the link between satellite-derived forest phenology and
field-derived forest productivity remains opaque. We used a unique
combination of a MODIS enhanced vegetation index (EVI) dataset, a wood
production model based on climate data and direct litterfall observations at an
intra-annual timescale in order to question the synchronism of leaf
and wood production in tropical forests. Even though leaf and wood
biomass fluxes had the same range (respectively 2.4 ± 1.4
and 2.2 ± 0.4 Mg C ha−1 yr−1), they occurred separately in
time. EVI increased with leaf renewal at the
beginning of the dry season, when solar irradiance was at its
maximum. At this time, wood production stopped. At the onset of the
rainy season, when new leaves were fully mature and water available
again, wood production quickly increased to reach its maximum in
less than a month, reflecting a change in carbon allocation from
short-lived pools (leaves) to long-lived pools (wood). The time lag
between peaks of EVI and wood production (109 days) revealed
a substantial decoupling between the leaf renewal assumed to be driven by irradiance
and the water-driven wood production. Our work is a first attempt to
link EVI data, wood production and leaf phenology at a seasonal timescale in a tropical evergreen rainforest and pave the way to develop
more sophisticated global carbon cycle models in tropical forests. |
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