Vegetation baseline phenology from kilometric global LAI satellite products
Verger, Aleixandre (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Filella, Iolanda (Universitat Autònoma de Barcelona. Departament de Biologia Animal, de Biologia Vegetal i d'Ecologia)
Baret, Frédéric (Environnement Méditerranéen et Modélisation des Agro-Hydrosystèmes)
Peñuelas, Josep (Universitat Autònoma de Barcelona. Departament de Biologia Animal, de Biologia Vegetal i d'Ecologia)

Date:	2016
Abstract:	Land surface phenology derived from remotely sensed satellite data can substantially improve our macroecological knowledge and the representation of phenology in earth system models. We characterized the baseline phenology of the vegetation at the global scale from the GEOCLIM climatology of leaf area index (LAI) estimated from 1-km SPOT-VEGETATION time series for 1999-2010. The phenological metrics were calibrated over an ensemble of ground observations of the timing of leaf unfolding and autumnal colouring of leaves. The start and end of season were best identified using respectively 30% and 40% threshold of LAI amplitude values. The accuracy of the derived phenological metrics, evaluated using available ground observations for birch forests over Europe (and lilac shrubs over North America), improved as compared to those derived from MODIS-EVI and produced an overall root mean square error of 7 days (19 days) for the timing of the start of season, 15 for the end of season, and 16 for the length of season. The spatial patterns of the derived LAI phenology agreed well with those from MODIS-EVI and -NDVI, although the timing of the start, end, and length of season differed by about one month at the global scale, with higher uncertainties in areas of limited seasonality of the satellite signal and systematic biases due to the differences in the methodologies and datasets. The baseline LAI phenology was spatially consistent with the global distributions of climatic drivers and biome land cover.
Grants:	European Commission 218795 European Commission 32-566 European Commission 32-594 Ministerio de Economía y Competitividad CGL2013-48074-P Agència de Gestió d'Ajuts Universitaris i de Recerca 2014/SGR-274 European Commission 610028
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, i la comunicació pública de l'obra, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original. No es permet la creació d'obres derivades.
Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Subject:	Climatology of land surface phenology ; Mean annual seasonal cycle ; Leaf area index ; SPOT-VEGETATION ; MODIS ; Ground observations ; Climatic drivers
Published in:	Remote sensing of environment, Vol. 178, (June 2016) , p. 1-14, ISSN 0034-4257

DOI: 10.1016/j.rse.2016.02.057

Post-print 48 p, 2.1 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > CREAF (Centre de Recerca Ecològica i d'Aplicacions Forestals) > Imbalance-P
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Articles > Published articles