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Estimating architecture-based metabolic scaling exponents of tropical trees using terrestrial LiDAR and 3D modelling / Alvaro Lau in Forest ecology and management, vol 439 (1 May 2019)  

Public [article]  inForest ecology and management > vol 439 (1 May 2019) . - pp 132-145 Titre : Estimating architecture-based metabolic scaling exponents of tropical trees using terrestrial LiDAR and 3D modelling Type de document : Article/Communication Auteurs : Alvaro Lau, Auteur ; Christopher Martius, Auteur ; Harm Bartholomeus, Auteur ; et al., Auteur Année de publication : 2019 Article en page(s) : pp 132-145 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie [Termes IGN] allométrie [Termes IGN] bois sur pied [Termes IGN] branche (arbre) [Termes IGN] diamètre des arbres [Termes IGN] données lidar [Termes IGN] forêt tropicale [Termes IGN] Guyana [Termes IGN] mise à l'échelle [Termes IGN] modélisation 3D [Termes IGN] semis de points [Termes IGN] structure d'un peuplement forestier [Termes IGN] télémétrie laser terrestre Résumé : (auteur) The geometric structure of tree branches has been hypothesized to relate to the mechanical safety and efficiency of resource transport within a tree. As such, the topology of tree architecture links physical properties within a tree and influences the interaction of the tree with its environment. Prior work suggests the existence of general principles which govern tree architectural patterns across of species and bio-geographical regions. In particular, West, Brown and Enquist (WBE, 1997) and Savage et al. (2010) derive scaling exponents (branch radius scaling ratio and branch length scaling ratio ) from symmetrical branch parameters and from these, an architecture-based metabolic scaling rate () for the whole tree. With this key scaling exponent, the metabolism (e.g., number of leaves, respiration, etc.) of a whole tree, or potentially a group of trees, can be estimated allometrically. Until now, branch parameter values have been measured manually; either from standing live trees or from harvested trees. Such measurements are time consuming, labour intensive and susceptible to subjective errors. Remote sensing, and specifically terrestrial LiDAR (TLS), is a promising alternative, being objective, scalable, and able to collect large quantities of data without destructive sampling. In this paper, we calculated branch length, branch radius, and architecture-based metabolic rate scaling exponents by first using TLS to scan standing trees and then fitting quantitative structure models (TreeQSM) models to 3D point clouds from nine trees in a tropical forest in Guyana. To validate these TLS-derived scaling exponents, we compared them with exponents calculated from direct field measurements of all branches >10 cm at four scales: branch-level, cumulative branch order, tree-level and plot-level. We found a bias on the estimations of and exponents due to a bias on the reconstruction of the branching architecture. Although TreeQSM scaling exponents predicted similar as the manually measured exponents, this was due to the combination of and scaling exponents which were both biased. Also, the manually measured and scaling exponents diverged from the WBE’s theoretical exponents suggesting that trees in tropical environments might not follow the predictions for the symmetrical branching geometry proposed by WBE. Our study provides an alternative method to estimate scaling exponents at both the branch- and tree-level in tropical forest trees without the need for destructive sampling. Although this approach is based on a limited sample of nine trees in Guyana, it can be implemented for large-scale plant scaling assessments. These new data might improve our current understanding of metabolic scaling without harvesting trees. Numéro de notice : A2019-485 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.foreco.2019.02.019 Date de publication en ligne : 07/03/2019 En ligne : https://doi.org/10.1016/j.foreco.2019.02.019 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93664 [article]

Towards a system combining SAR and optical Sentinel data to monitor gold mining in the Guiana shield / Mathieu Rahm (2016)    

Public Titre : Towards a system combining SAR and optical Sentinel data to monitor gold mining in the Guiana shield Type de document : Article/Communication Auteurs : Mathieu Rahm, Auteur ; Cédric Lardeux, Auteur ; Pierre-Louis Frison , Auteur ; et al., Auteur Editeur : Paris : Agence Spatiale Européenne ASE / European Space Agency ESA Année de publication : 2016 Conférence : LPS 2016, ESA Living Planet Symposium 09/05/2016 13/05/2016 Prague République tchèque programme sans actes Importance : 60 p. Format : 21 x 30 cm Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] analyse diachronique [Termes IGN] Brésil [Termes IGN] déboisement [Termes IGN] fusion d'images [Termes IGN] Guyana [Termes IGN] Guyane (département français) [Termes IGN] image Sentinel-MSI [Termes IGN] image Sentinel-SAR [Termes IGN] mine d'or [Termes IGN] pollution des eaux [Termes IGN] Suriname Résumé : (auteur) Included in the larger Guiana Shield ecosystem, Suriname, Guyana, French Guiana and the Brazilian state of Amapá possess one of the largest continuous tracts of pristine forest in the world. Under little threat until fifteen years ago, deforestation and forest degradation are of increasing concern in the region. Gold mining activities driven by the sustained increase of gold price has experienced a significant boom and represents nowadays one of the main driver. The pollution of rivers and streams by mercury used in small-scale gold mining is also expanding, which increases risks to local population health and freshwater biodiversity. In 2010, the French National Forest Office (ONF) showed by using optical satellite images at medium and high resolution (HR) that gold mining activities’ impacts on forest cover and freshwater increased approximately by a factor three in the region between 2001 and 2008. More recently, Alvarez-Berríos et al. (2015) pointed out a sustained acceleration of deforestation caused by gold mining in the Guiana shield between 2007 and 2013. However, this study which was performed using low resolution data at the scale of South America has limited capacity to detect gold mining, especially in the high forest cover of Guiana Shield where small- and medium-scale operations account for most of the deforestation. To overcome this limitation, the REDD+ for the Guiana Shield project conducted a study co-funded by WWF Guianas to update for 2014 the ONF 2001-2008 results, using optical multi-sensors data at medium and high resolution. The study was carried out following a unique collaborative and participatory approach involving a team of experts from the forestry and environmental services of each territory, namely SEMA (Amapá-Brazil), ONF (French Guiana-France), GFC (Guyana), and SBB (Suriname). The results confirmed the rapid expansion of the activity in the region where more than 92,000 ha were newly deforested between 2008 and 2014, compared to approximately 46,000 ha during the period 2001-2008. In 2014, more than 9,000 km of waterways were in direct contact with mining sites, which is approximately 6.5 times more than in 2001. Although a reliable, accurate and robust regional methodology has been developed and operationally implemented, the frequent and widespread cloud cover of the Guianan moist forest region represents a challenge for the use of optical HR data. The need to process time series of satellite images in most areas to reduce cloud cover is time-consuming. Despite processing more than two hundreds images, 3.6% of the study area remained masked by clouds. The recent free access to SAR HR Sentinel-1 data offers great opportunities to improve the process. SAR sensors can peer through clouds and their sensitivity to soil moisture can help to better detect small-scale mining sites. Therefore, the REDD+ for the Guiana Shield project has started to build capacities in the region on SAR image interpretation and processing using the Sentinel Application Platform (SNAP). A first mosaic of Sentinel-1 data covering Suriname, Guyana, French Guiana and the Brazilian state of Amapá has been created and automated pre-processing steps have been developed. The integration of Sentinel-1 data in the regional gold mining monitoring system has been successfully tested in four study sites, one in each country. The coming free access to optical HR Sentinel-2 data opens even more perspectives towards the development of cost-effective monitoring systems in the region, especially valuable in the context of REDD+. This paper first presents the results of the impact of gold mining activities on the forest cover and freshwater for 2014 and shows the evolution since 2001. Secondly, it provides the first outcomes towards the development of time- and cost-efficient forest monitoring systems in the region. Numéro de notice : C2016-058 Affiliation des auteurs : LASTIG MATIS+Ext (2012-2019) Thématique : IMAGERIE Nature : Communication nature-HAL : ComAvecCL&ActesPubliésIntl DOI : sans En ligne : http://lps16.esa.int/page_session187.php#1306p Format de la ressource électronique : URL abstract Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91912

Documents numériques

en open access Towards a System Combining SAR... (final report) - pdf auteur Adobe Acrobat PDF

Atlas des migrations nord-brésiliennes vers la Guyane, Projet ANR / Maeve De France (2009)

Public Titre : Atlas des migrations nord-brésiliennes vers la Guyane, Projet ANR : Dynamique des circulations migratoires et mobilités transfrontalières entre Guyana, Surinam, Brésil, Guyane et Haïti Type de document : Atlas/Carte Auteurs : Maeve De France, Auteur ; Luc Cambrézy, Éditeur scientifique ; Rainer Zaiss, Éditeur scientifique Editeur : Paris : Institut de Recherche pour le Développement IRD Année de publication : 2009 Importance : 40 p. Format : 42 x 30 cm Langues : Français (fre) Descripteur : [Vedettes matières IGN] Cartographie thématique [Termes IGN] Brésil [Termes IGN] Guyana [Termes IGN] Guyane (département français) [Termes IGN] Haïti [Termes IGN] migration humaine [Termes IGN] migration pendulaire [Termes IGN] Suriname Index. décimale : ATLAS Atlas Numéro de notice : 15789 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Atlas Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=34802

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Code-barres	Cote	Support	Localisation	Section	Disponibilité
15789-01	ATLAS	Atlas / Beau livre	Centre de documentation	En réserve L003	Disponible

The use of forest inventory data for a National Protected Area Strategy in Guyana / Hans Ter Steege in Biodiversity & Conservation, vol 7 n° 11 ([01/11/1998])  

Public [article]  inBiodiversity & Conservation > vol 7 n° 11 [01/11/1998] . - 1457-1483 Titre : The use of forest inventory data for a National Protected Area Strategy in Guyana Type de document : Article/Communication Auteurs : Hans Ter Steege, Auteur Année de publication : 1998 Article en page(s) : 1457-1483 Langues : Français (fre) Descripteur : [Termes IGN] aire protégée [Termes IGN] biodiversité végétale [Termes IGN] forêt équatoriale [Termes IGN] géologie locale [Termes IGN] Guyana [Termes IGN] inventaire forestier étranger (données) [Termes IGN] parc naturel national [Vedettes matières IGN] Inventaire forestier Résumé : (auteur) Forest inventories are largely neglected in the debate of national parks selection in Guyana (and probably elsewhere). Because taxonomic data are often scant and biased towards are as of high collecting effort, large scale forest inventory data can be a useful tool adding to a knowledge database for forests. In this paper the use of forest inventories to select national parks in Guyana is assessed. With the data of a large scale inventory five forest regions could be distinguished and two were added on the base of existing other information. Forest composition in Guyana is largely determined by geology at a national level and soil type at regional level. Species diversity is higher in the south of Guyana, possibly due to higher disturbance and is also higher on the better soils. It is concluded that a selection of national parks in Guyana should include a sample of all seven regions, including as much soil variation as possible. Because of land use conflicts in central Guyana, this area is in need of quick attention of Guyana's policy makers. Numéro de notice : A1998-200 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1023/A:1008893920157 En ligne : http://dx.doi.org/10.1023/A:1008893920157 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92691 [article]

Estimating erosion rates of tropical shorelines from Radarsat-1 / Vern Singhroy (01/09/1998)  

Public contenu dans ISPRS Commission 7 Symposium Resource and environmental monitoring 1996-2000 / Gabor Remetey-Fulopp (1998)   Titre : Estimating erosion rates of tropical shorelines from Radarsat-1 Type de document : Article/Communication Auteurs : Vern Singhroy, Auteur ; Marx Barbosa, Auteur Editeur : International Society for Photogrammetry and Remote Sensing ISPRS Année de publication : 01/09/1998 Conférence : ISPRS 1998, Commission 7 symposium on Resource and environmental monitoring 01/09/1998 04/09/1998 Budapest Hongrie OA Proceedings archives Importance : pp 174 - 177 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] érosion côtière [Termes IGN] forêt tropicale [Termes IGN] Guyana [Termes IGN] image Radarsat [Termes IGN] littoral [Termes IGN] mangrove [Termes IGN] risque naturel [Termes IGN] zone intertropicale Résumé : (Auteur) On a global scale, shorelines are eroding at an increasing rate. The local shoreline geomorphology and regional differences in coastal processes are fundamental in estimating erosion rates. Our results show that in the permanently cloudy tropical coastal areas of and north east Brazil, RADARSAT S7 image is particularly useful to map areas of erosion, and deposition, as well as the adjacent affected coastal land use. Coastal changes were estimated by comparing recent RADARSAT images with previous topographic maps. In north east Brazil erosion rates on fractured quaternary sediments vary from 0 to 12 meters a year, and on the more resistant sandstone erosion rates vary from 0 to 6 meters a year. In Guyana, low flat areas below sea level, erosion rates vary from 0 to 25 meters a year. In EI Nino year, these estimates are expected to increase. Numéro de notice : C1998-039 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Communication DOI : sans En ligne : https://goobi.tib.eu/viewer/image/1669065049/197/ Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=65763

Les Guyanes / J.C. Giacottino (1984)

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La main-d'œuvre dans les Guyanes / J. Duchesne-Fournet (1905)

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