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| Titel |
Remote sensing of ecosystem light use efficiency with MODIS-based PRI |
| VerfasserIn |
A. Goerner, M. Reichstein, E. Tomelleri, N. Hanan, S. Rambal, D. Papale, D. Dragoni, C. Schmullius |
| 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 ; 8, no. 1 ; Nr. 8, no. 1 (2011-01-26), S.189-202 |
| Datensatznummer |
250005354
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| Publikation (Nr.) |
 copernicus.org/bg-8-189-2011.pdf |
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| Zusammenfassung |
| Several studies sustained the possibility that a photochemical reflectance
index (PRI) directly obtained from satellite data can be used as a proxy for
ecosystem light use efficiency (LUE) in diagnostic models of gross primary
productivity. This modelling approach would avoid the complications that are
involved in using meteorological data as constraints for a fixed maximum LUE.
However, no unifying model predicting LUE across climate zones and time based
on MODIS PRI has been published to date. In this study, we evaluate the
effectiveness with which MODIS-based PRI can be used to estimate ecosystem light
use efficiency at study sites of different plant functional types and
vegetation densities. Our objective is to examine if known limitations such
as dependence on viewing and illumination geometry can be overcome and a
single PRI-based model of LUE (i.e. based on the same reference band) can be
applied under a wide range of conditions. Furthermore, we were interested in
the effect of using different faPAR (fraction of absorbed photosynthetically
active radiation) products on the in-situ LUE used as ground truth and thus
on the whole evaluation exercise. We found that estimating LUE at site-level
based on PRI reduces uncertainty compared to the approaches relying on a
maximum LUE reduced by minimum temperature and vapour pressure deficit.
Despite the advantages of using PRI to estimate LUE at site-level, we could
not establish an universally applicable light use efficiency model based on
MODIS PRI. Models that were optimised for a pool of data from several sites
did not perform well. |
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