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Estimating tropical pasture quality at canopy level using band depth analysis with continuum removal in the visible domain / Onisimo Mutanga in International Journal of Remote Sensing IJRS, vol 26 n° 6 (March 2005)
[article]
Titre : Estimating tropical pasture quality at canopy level using band depth analysis with continuum removal in the visible domain Type de document : Article/Communication Auteurs : Onisimo Mutanga, Auteur ; Andrew K. Skidmore, Auteur ; et al., Auteur Année de publication : 2005 Article en page(s) : pp 1093 - 1108 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] analyse spectrale
[Termes IGN] bande visible
[Termes IGN] contrôle qualité
[Termes IGN] faune
[Termes IGN] forêt tropicale
[Termes IGN] herbe
[Termes IGN] paturage
[Termes IGN] radiométrie
[Termes IGN] réflectance végétale
[Termes IGN] régression linéaire
[Termes IGN] zone intertropicaleRésumé : (Auteur) Pasture quality, expressed as a percentage of total digestible nutients (nitrogen, potassium, phosphorous, calcium and magnesium) is a major factor determining the grazing patterns of wildlife and livestock. Existing rangeland monitoring techniques seldom reflect the nutritive quality of the pastures and are consequently of limited value in explaining animal distribution. Techniques that can estimate pasture quality on a large scale are therefore critical in understanding and explaining wildlife and livestock distribution. We present the results of a greenhouse experiment designed to estimate the concentrations of nitrogen, potassium, phosphorous calcium, magnesium and non-detergent fibre (NDF), using the reflectance of a tropical grass (Cenchrus ciliaris) canopy. Canopy spectral measurements were taken under controlled laboratory conditins using a GER 3700 spectroradiometer. We tested the utility of using the band depth analysis methodology in the visible region (where water absorption is less effective) to estimate foliar chemistry in fresh canopies. Continuum removal was applied to the visible absorption feature centred at 670 nm, and band depth ratios (BDRs) were calculated. Stepwise linear regression was used to select wavelenghts from calculated BDRs that were highly correlated with foliar chemistry in randomly selected training dataset. The resulting regression models were used to predict foliar chemistry in a test dataset. Results indicate that stepwise regression models on band calculated from continuum-removed reflectance spectra could predict foliar nutrient concentration with high accuracy. The correlations were highest for magnesium and nitrogen (R2= 0.77 and 0.73 respectively, using the normalized band depth index (NDBI) between the measured and estimated biochemicals - a satisfactory result in estimating foliar chemistry in fresh standing pastures. With the advent of new sensors such as Hymap and MERIS these results lay the basis for developing algorithms to rapidly estimate and ultimately map pasture quality in tropical rangelands. Numéro de notice : A2005-145 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160512331326738 En ligne : https://doi.org/10.1080/01431160512331326738 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27283
in International Journal of Remote Sensing IJRS > vol 26 n° 6 (March 2005) . - pp 1093 - 1108[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 080-05061 RAB Revue Centre de documentation En réserve L003 Exclu du prêt Mapping tropical forest structure in south-eastern Madagascar using remote sensing and artificial neural networks / J.C. Ingram in Remote sensing of environment, vol 94 n° 4 (28/02/2005)
[article]
Titre : Mapping tropical forest structure in south-eastern Madagascar using remote sensing and artificial neural networks Type de document : Article/Communication Auteurs : J.C. Ingram, Auteur ; T.P. Dawson, Auteur ; R.J. Whittaker, Auteur Année de publication : 2005 Article en page(s) : pp 491 - 507 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] analyse des correspondances
[Termes IGN] analyse multibande
[Termes IGN] biodiversité
[Termes IGN] carte de la végétation
[Termes IGN] classification par réseau neuronal
[Termes IGN] densité
[Termes IGN] forêt tropicale
[Termes IGN] image Landsat-ETM+
[Termes IGN] Madagascar
[Termes IGN] Normalized Difference Vegetation Index
[Termes IGN] radiance
[Termes IGN] troncRésumé : (Auteur) Tropical forest condition has important implications for biodiversity, climate change and human needs. Structural features of forests can serve as useful indicators of forest condition and have the potential to be assessed with remotely sensed imagery, which can provide quantitative information on forest ecosystems at high temporal and spatial resolutions. Herein, we investigate the utility of remote sensing for assessing, predicting and mapping two important forest structural features, stem density and basal area, in tropical, littoral forests in southeastern Madagascar. We analysed the relationships of basal area and stem density measurements to the Normalised Difference Vegetation Index (NDVI) and radiance measurements in bands 3, 4, 5 and 7 from the Landsat Enhanced Thematic Mapper Plus (ETM+). Strong relationships were identified among all of the individual bands and field based measurements of basal area (p Numéro de notice : A2005-069 Affiliation des auteurs : non IGN Thématique : BIODIVERSITE/FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2004.12.001 En ligne : https://doi.org/10.1016/j.rse.2004.12.001 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27207
in Remote sensing of environment > vol 94 n° 4 (28/02/2005) . - pp 491 - 507[article]Assessing the feasibility of a global model for multi-temporal burned area mapping using Spot-Vegetation data / J.M. Silva in International Journal of Remote Sensing IJRS, vol 25 n° 22 (November 2004)
[article]
Titre : Assessing the feasibility of a global model for multi-temporal burned area mapping using Spot-Vegetation data Type de document : Article/Communication Auteurs : J.M. Silva, Auteur ; J.F. Cadima, Auteur ; J.M. Pereira, Auteur ; J.M. Gregoire, Auteur Année de publication : 2004 Article en page(s) : pp 4889 - 4913 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] bande infrarouge
[Termes IGN] cartographie thématique
[Termes IGN] étude de faisabilité
[Termes IGN] forêt tropicale
[Termes IGN] image SPOT-Végétation
[Termes IGN] incendie
[Termes IGN] Normalized Difference Vegetation Index
[Termes IGN] zone boréale
[Termes IGN] zone intertropicale
[Termes IGN] zone tempéréeRésumé : (Auteur) The possibility of using the Système Probatoire de l'Observation de la Terre (SPOT)-VEGETATION (VGT) data for global burned area mapping with a single algorithm was investigated. Using VGT images from south-eastern Africa, the Iberian Peninsula and south-eastern Siberia/north-eastern China, we analysed the variability of the spectral signature of burned areas and its relationship with land cover, and performed the selection of the best variables for burned area mapping. The results show that in grasslands and croplands, near-infrared (NIR) and short-wave infrared (SWIR) reflectance always decreases as a result of fire. In forests and woodlands, there may occur a simultaneous decrease of SWIR and NIR or an increase of SWIR and a decrease of NIR. Burning of green vegetation (high values of the Normalized Difference Vegetation Index (NDVI)) tends to result in an increase of the SWIR. The best variables for burned area mapping are different in each region. Only the NIR allows a good discrimination of burned areas in all study areas. We derived a logistic regression model for multi-temporal burned area mapping in tropical, temperate and boreal regions, which handles the spectral variability of burned areas dependent on the type of vegetation. The results underline the feasibility of a single model for global burned area mapping. Numéro de notice : A2004-486 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160412331291251 En ligne : https://doi.org/10.1080/01431160412331291251 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27004
in International Journal of Remote Sensing IJRS > vol 25 n° 22 (November 2004) . - pp 4889 - 4913[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 080-04201 RAB Revue Centre de documentation En réserve L003 Exclu du prêt Estimation of interannual variation in productivity of global vegetation using NDVI data / Z.M. Chen in International Journal of Remote Sensing IJRS, vol 25 n° 16 (August 2004)
[article]
Titre : Estimation of interannual variation in productivity of global vegetation using NDVI data Type de document : Article/Communication Auteurs : Z.M. Chen, Auteur ; I.S. Babiker, Auteur ; et al., Auteur Année de publication : 2004 Article en page(s) : pp 3139 - 3159 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] analyse diachronique
[Termes IGN] bilan du carbone
[Termes IGN] biosphère
[Termes IGN] changement climatique
[Termes IGN] dioxyde de carbone
[Termes IGN] forêt tempérée
[Termes IGN] forêt tropicale
[Termes IGN] image NOAA-AVHRR
[Termes IGN] impact sur l'environnement
[Termes IGN] Normalized Difference Vegetation Index
[Termes IGN] production primaire nette
[Termes IGN] répartition géographique
[Termes IGN] variation saisonnièreRésumé : (Auteur) The interannual variation of global vegetation net primary production (NPP), which is crucial to understanding the role of terrestrial biosphere in the global carbon cycle, is still poorly understood. Currently, remote sensing emerges as a useful tool for estimating NPP through monitoring global vegetation distribution and growth. The objective of this study was to utilize the multi-year monthly Normalized Difference Vegetation Index (NDVI) dataset of 1987-1997 from the Advanced Very High Resolution Radiometer (AVHRR) to investigate the interannual variation in productivity of global vegetation due to climate variation, human activities, and environmental events. A decision tree algorithm based on simple metrics (minimum, maximum, mean and amplitude) was employed to classify the global vegetation from NDVI data and obtain the annual vegetation growth areas. Then, annual NPP was computed using the annual vegetation growth areas and the predefined NPP coefficients given in a 1990 Intergovernmental Panel on Climate Change (IPCQ) report. The NPP exhibited a slightly increasing trend through the 11 years. However, interannual variations were observed to be mainly determined by variation in growth of tropical and temperate evergreen forests. These fluctuations were consistently correlated to El Niño/La Niña events. Although the interannual variation in primary productivity of global vegetation is expected to influence the atmospheric C02 concentration over the one-decade period, it is unlikely to have solely caused the anomalously low growth in 1992-1993. The adopted methodology enabled close examination of variability in vegetation growth at the biome scale as well as at global scale. Numéro de notice : A2004-301 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/0143116032000160435 En ligne : https://doi.org/10.1080/0143116032000160435 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26828
in International Journal of Remote Sensing IJRS > vol 25 n° 16 (August 2004) . - pp 3139 - 3159[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 080-04141 RAB Revue Centre de documentation En réserve L003 Disponible Two decades of normalized difference vegetation index changes in South America: identifying the imprint of global change / J.M. Paruelo in International Journal of Remote Sensing IJRS, vol 25 n° 14 (July 2004)
[article]
Titre : Two decades of normalized difference vegetation index changes in South America: identifying the imprint of global change Type de document : Article/Communication Auteurs : J.M. Paruelo, Auteur ; M.F. Garbulsky, Auteur ; et al., Auteur Année de publication : 2004 Article en page(s) : pp 2793 - 2806 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] Amérique du sud
[Termes IGN] analyse diachronique
[Termes IGN] atmosphère terrestre
[Termes IGN] biome
[Termes IGN] changement climatique
[Termes IGN] couvert végétal
[Termes IGN] forêt équatoriale
[Termes IGN] forêt tempérée
[Termes IGN] Normalized Difference Vegetation Index
[Termes IGN] photosynthèse
[Termes IGN] production primaire brute
[Termes IGN] savaneRésumé : (Auteur) Estimates of carbon uptake at the continental scale become urgently needed as the role of countries as net sinks or sources of carbon gains political and economic importance. Despite uncertainties related to radiation use efficiency, the amount of photosynthetically active radiation (PAR) intercepted by the canopy is a reliable estimator of primary production. Theoretical and empirical data support the relationship between the Normalized Difference Vegetation Index (NDVI) derived from the Advanced Very High Resolution Radiometer sensor on National Oceanic & Atmospheric Administration satellites and the fraction of PAR intercepted by green canopies. It is shown, for the period 1981-2000, that there is an overall increase in the radiation intercepted by the canopy over South America by 1.3%, with rainforests making the largest absolute contribution (45%), followed by savannas (23%). Under conditions of minimal agricultural use, disturbance and anthropogenic N deposition, humid temperate forests showed the highest proportional increase in NDVI during the last two decades (4.9%). Deserts showed a net reduction in NDVI relative to the 1981-1985 average (-4.4%). The expansion of agriculture over the last two decades was associated with NDVI reductions over subtropical forests. NDVI trends in South American region highlight a biome-dependent imprint of major global change noticeable in only two decades. Numéro de notice : A2004-292 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160310001619526 En ligne : https://doi.org/10.1080/01431160310001619526 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26819
in International Journal of Remote Sensing IJRS > vol 25 n° 14 (July 2004) . - pp 2793 - 2806[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 080-04121 RAB Revue Centre de documentation En réserve L003 Exclu du prêt L'altimétrie par laser scanner aéroporté / B. Bergeon in Géomatique expert, n° 35 (01/06/2004)PermalinkLeaf Area Index measurements in a tropical moist forest: a case study from Costa Rica / M. Kalacska in Remote sensing of environment, vol 91 n° 2 (30/05/2004)PermalinkSmall-footprint lidar estimation of sub-canopy elevation and tree height in a tropical rain forest landscape / M.L. Clarke in Remote sensing of environment, vol 91 n° 1 (15/05/2004)PermalinkHyperion, Ikonos, ALI, and ETM+ sensors in the study of African rainforests / Prasad S. Thenkabail in Remote sensing of environment, vol 90 n° 1 (15/03/2004)PermalinkDynamiques et représentations spatiales de la déforestation en Côte d'Ivoire : l'exemple de la foret classée du Haut-Sassandra (1986-2001) / J. Oszwald in Photo interprétation, vol 40 n° 1 (Mars 2004)PermalinkImproving tropical forest mapping using multi-date Landsat TM data and pre-classification image smoothing / C. Tottrup in International Journal of Remote Sensing IJRS, vol 25 n° 4 (February 2004)PermalinkProspects for quantifying structure, floristic composition and species richness of tropical forests / T.W. Gillespie in International Journal of Remote Sensing IJRS, vol 25 n° 4 (February 2004)PermalinkPredicting in situ pasture quality in the Kruger National Park, South Africa, using continuum-removed absorption features / Onisimo Mutanga in Remote sensing of environment, vol 89 n° 3 (15/02/2004)PermalinkLinear features extraction in rain forest context from interferometric SAR images by fusion of coherence and amplitude information / V.P. Onana in IEEE Transactions on geoscience and remote sensing, vol 41 n° 11 (November 2003)PermalinkDétermination de classes de relief à l'aide de données ERS1 sur des bassins versants tropicaux de Guyane / Marc Lointier in Bulletin [Société Française de Photogrammétrie et Télédétection], n° 172 (Octobre 2003)Permalink