Leaf area index estimation with MODIS reflectance time series and model inversion during full rotations of Eucalyptus plantations

Le Maire Guerric, Marsden Claire, Verhoef Wouter, Ponzoni Flávio Jorge, Lo Seen Danny, Bégué Agnès, Stape Jose Luiz, Nouvellon Yann. 2011. Leaf area index estimation with MODIS reflectance time series and model inversion during full rotations of Eucalyptus plantations. Remote Sensing of Environment, 115 (2) : 586-599.

Quartile : Outlier, Sujet : REMOTE SENSING / Quartile : Q1, Sujet : ENVIRONMENTAL SCIENCES / Quartile : Outlier, Sujet : IMAGING SCIENCE & PHOTOGRAPHIC TECHNOLOGY

Liste HCERES des revues (en SHS) : oui

Thème(s) HCERES des revues (en SHS) : Géographie-Aménagement-Urbanisme-Architecture

Résumé : The leaf area index (LAI) of fast-growing Eucalyptus plantations is highly dynamic both seasonally and interannually, and is spatially variable depending on pedo-climatic conditions. LAI is very important in determining the carbon and water balance of a stand, but is difficult to measure during a complete stand rotation and at large scales. Remote-sensing methods allowing the retrieval of LAI time series with accuracy and precision are therefore necessary. Here, we tested two methods for LAI estimation from MODIS 250m resolution red and near-infrared (NIR) reflectance time series. The first method involved the inversion of a coupled model of leaf reflectance and transmittance (PROSPECT4), soil reflectance (SOILSPECT) and canopy radiative transfer (4SAIL2). Model parameters other than the LAI were either fixed to measured constant values, or allowed to vary seasonally and/or with stand age according to trends observed in field measurements. The LAI was assumed to vary throughout the rotation following a series of alternately increasing and decreasing sigmoid curves. The parameters of each sigmoid curve that allowed the best fit of simulated canopy reflectance to MODIS red and NIR reflectance data were obtained by minimization techniques. The second method was based on a linear relationship between the LAI and values of the GEneralized Soil Adjusted Vegetation Index (GESAVI), which was calibrated using destructive LAI measurements made at two seasons, on Eucalyptus stands of different ages and productivity levels. The ability of each approach to reproduce field-measured LAI values was assessed, and uncertainty on results and parameter sensitivities were examined. Both methods offered a good fit betweenmeasured and estimated LAI (R2=0.80 and R2=0.62 for model inversion and GESAVI-based methods, respectively), but the GESAVI-based method overestimated the LAI at young ages.

Mots-clés Agrovoc : plantations, Eucalyptus, indice de surface foliaire, mesure (activité), télédétection, cycle du carbone, méthodologie, réflectométrie, spectrométrie, modélisation environnementale

Mots-clés géographiques Agrovoc : Brésil

Classification Agris : F62 - Physiologie végétale - Croissance et développement
U10 - Informatique, mathématiques et statistiques
U30 - Méthodes de recherche
K10 - Production forestière

Champ stratégique Cirad : Axe 1 (2005-2013) - Intensification écologique

Auteurs et affiliations

• Le Maire Guerric, CIRAD-PERSYST-UPR Ecosystèmes de plantations (FRA) ORCID: 0000-0002-5227-958X
• Marsden Claire
• Verhoef Wouter, University of Twente (NLD)
• Ponzoni Flávio Jorge, INPE (BRA)
• Lo Seen Danny, CIRAD-ES-UMR TETIS (FRA) ORCID: 0000-0002-7773-2109
• Bégué Agnès, CIRAD-ES-UMR TETIS (FRA)
• Stape Jose Luiz, North Carolina State University (USA)
• Nouvellon Yann, CIRAD-PERSYST-UPR Ecosystèmes de plantations (BRA) ORCID: 0000-0003-1920-3847

Source : Cirad - Agritrop (https://agritrop.cirad.fr/558073/)

Métriques

[ Page générée et mise en cache le 2024-12-18 ]