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3D stem modelling in tropical forest: towards improved biomass and biomass change estimates / Sébastien Bauwens (2022)
Titre : 3D stem modelling in tropical forest: towards improved biomass and biomass change estimates Type de document : Thèse/HDR Auteurs : Sébastien Bauwens, Auteur Editeur : Gembloux [Belgique] : Université de Liège - Gembloux Agro-Bio Tech Année de publication : 2022 Importance : 146 p. Format : 21 x 30 cm Note générale : Bibliographie
Dissertation originale présentée en vue de l'obtention du grade de Docteur en Sciences Agronomiques et Ingénierie BiologiqueLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] analyse comparative
[Termes IGN] biomasse aérienne
[Termes IGN] cartographie et localisation simultanées
[Termes IGN] Congo
[Termes IGN] diamètre à hauteur de poitrine
[Termes IGN] dioxyde de carbone
[Termes IGN] données lidar
[Termes IGN] écosystème forestier
[Termes IGN] forêt tropicale
[Termes IGN] hauteur des arbres
[Termes IGN] inventaire forestier (techniques et méthodes)
[Termes IGN] lidar mobile
[Termes IGN] modèle de croissance végétale
[Termes IGN] modèle numérique de terrain
[Termes IGN] placette d'échantillonnage
[Termes IGN] puits de carbone
[Termes IGN] semis de points
[Termes IGN] stéréoscopie
[Termes IGN] structure-from-motion
[Termes IGN] télémétrie laser terrestreRésumé : (auteur) Tropical forests are the main contributors of CO2 emissions between the biosphere and the atmosphere in the land use sector. The deforestation and degradation of these forests are the main sources of emissions from this sector, which accounts for 15% of the world's CO2 emissions. The monitoring of CO2 emissions and removals from tropical forests requires fine measurements of their trees. These measurements are then used as inputs in allometric model to predict the tree aboveground biomass and thus indirectly their equivalent in CO2. However, a significant proportion of trees in tropical forests show morphological singularities on the stem such as buttresses or other irregularities. The height (HPOM) of the diameter measured (DPOM) is therefore commonly raised above the buttresses to reach a circular part of the stem. The standard of measuring the diameter at breast height (DBH) is then lost. In this context, this thesis aims to improve the monitoring of tropical trees with stem irregularities by using recent three-dimensional (3D) measurement tools and developing a model-based approach to harmonize height measurements of the diameterdo. First, we evaluated the potential of the close-range terrestrial photogrammetric approach (CRTP) to measure irregular shaped stems. The advantage of this 3D approach is its low cost and ease of implementation as it only requires a camera and targets. Following the convincing results of this approach, we studied the quality of the allometric relationship between variables extracted from the stem cross-section at 1.3 m height and above-ground biomass. We found that the equivalent diameter of the basal area at 1.3 m height (DBH') correlates better with aboveground tree biomass and thus its carbon content than does diameter above buttress (DPOM). Therefore, harmonization of HPOM to 1.3 m height should be further studied to improve biomass estimates. Secondly, we investigated the potential of a hand-held mobile lidar scanner (HMLS) to measure in 3D not only one tree at a time but many trees from forest plots with a 15 m radius in Belgian temperate forest. To assess the HMLS, we compared it to 3D measurements made with a more commonly used static terrestrial laser scanning (TLS) and with conventional forest inventory diameter and position measurements. The HMLS has a better 3D spatial coverage of the stems than the TLS and the precision of the stem diameter measurements is also better with the HMLS. Setting up the plot and scanning it from five locations with the TLS takes three times longer than scanning with HMLS. This pioneering work shows us the potential of using HMLS in tropical forests through its speed of execution and its important spatial coverage at the stem level, an important issue for irregular shaped tree stems. Thirdly, we developed and assessed a model-based approach for harmonizing HPOM to correct the bias induced by irregular stems in the aboveground biomass estimates of forest inventory plots. Following the estimation of DBH' using a taper model proposed in our study, we find that conventional aboveground biomass estimates (i.e. with only DPOM), compared to estimates made with DBH', show an increasing divergence with the increase of irregular stems proportion within plots and going up to -15% in our study. These results show the importance of considering HPOM when estimating aboveground biomass in tropical forests, especially in forests with many irregular stems. Estimates of the evolution of plot above-ground biomass over time should also be revised to better consider the biomass growth of irregular shaped tree stems, which has been underestimated until now. Finally, based on the results of this research, we summarize the 3D measurement tools currently available and describe their advantages and disadvantages in the case of irregular stems. Based on available human and technical resources, we also give recommendations on the harmonization method to use in permanent sampling plots to correct the bias induced by irregular stems. Improved monitoring of these tropical trees may provide a better understanding of some of the residual, i.e. unexplained, terrestrial ecosystem CO2 sink currently noted in IPCC reports. Note de contenu : 1- General introduction
2- 3D measurements of irregularly shaped stems
3- 3D stem measurements at the plot level
4- Making tropical forest plots comparable
5- DiscussionNuméro de notice : 24037 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Thèse étrangère Note de thèse : Thèse de Doctorat : Sciences Agronomiques et Ingénierie Biologique : Liège : 2022 DOI : sans En ligne : https://hdl.handle.net/2268/293900 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101855 Contraintes observationnelles historiques sur la sensibilité climatique : implications pour les projections de la hausse du niveau de la mer / Jonathan Chenal (2022)
Titre : Contraintes observationnelles historiques sur la sensibilité climatique : implications pour les projections de la hausse du niveau de la mer Type de document : Thèse/HDR Auteurs : Jonathan Chenal , Auteur ; Benoit Meyssignac, Directeur de thèse Editeur : Toulouse : Université de Toulouse 3 Paul Sabatier Année de publication : 2022 Note générale : bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] chaleur
[Termes IGN] changement climatique
[Termes IGN] dioxyde de carbone
[Termes IGN] erreur systématique
[Termes IGN] montée du niveau de la mer
[Termes IGN] niveau de la mer
[Termes IGN] régression linéaire
[Termes IGN] série temporelle
[Termes IGN] température de surface de la merIndex. décimale : THESE Thèses et HDR Résumé : (auteur) Ma thèse explore l'estimation observationnelle de la sensibilité climatique d'équilibre (ECS) à partir des données instrumentales historiques et récentes, en particulier spatiales. L'ECS est la température globale moyenne de surface de la Terre atteinte après un doublement instantané de la concentration de dioxyde de carbone atmosphérique par rapport à la concentration préindustrielle. Cette quantité est la métrique fondamentale de l'amplitude du changement climatique contemporain, car l'évolution actuelle et future de nombreuses variables du système climatique, comme la température ou l'expansion thermique de l'océan, lui est fortement corrélée. L'ECS demeure cependant mal connue, puisque depuis le rapport Charney de 1979 jusqu'au Cinquième rapport d'évaluation du Groupe intergouvernemental d'experts sur le climat (GIEC), sa plage de valeurs probables se situait entre 1,5 et 4,5 degrés, avec un biais marqué entre estimations instrumentales, qui se situent dans la partie basse de l'intervalle, et estimations issues des modèles de climat, qui se situent dans la partie haute de l'intervalle. La cause principale de cette dispersion réside dans le fait que la sensibilité climatique varie avec le temps, en lien notamment avec l'effet radiatif des structures spatiales du réchauffement de surface, qui peuvent changer au cours du temps du fait de la variabilité interne du climat ou des variations historiques dans le type de forçage. Ma thèse utilise des séries temporelles observationnelles récentes de contenu de chaleur de l'océan et de température de surface, et une reconstruction récente de forçage radiatif, pour estimer le paramètre de rétroaction climatique, puis l'ECS, par régression linéaire de l'équation du bilan d'énergie planétaire. Dans ce processus, je prends en compte toutes les sources d'erreur et je les propage dans la régression afin d'obtenir une description exhaustive de l'incertitude observationnelle associée à l'ECS. Par ailleurs, j'utilise les variations temporelles du paramètre de rétroaction climatique simulées par les modèles de climat pour évaluer les biais et incertitudes associés à ce paramètre et dus à la structure spatiale du réchauffement historique. Sur la base du bilan d'énergie ainsi résolu sur 1971-2017, je démontre qu'il est très peu probable (p Numéro de notice : 17769 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Thèse française Organisme de stage : Laboratoire d'Etudes en Géophysique et Océanographie Spatiales LEGOS nature-HAL : Thèse DOI : sans En ligne : http://thesesups.ups-tlse.fr/5598/ Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=103338 Spatial distribution of lead (Pb) in soil: a case study in a contaminated area of the Czech Republic / Nicolas Francos in Geomatics, Natural Hazards and Risk, vol 13 (2022)
[article]
Titre : Spatial distribution of lead (Pb) in soil: a case study in a contaminated area of the Czech Republic Type de document : Article/Communication Auteurs : Nicolas Francos, Auteur ; Asa Gholizadeh, Auteur ; Eyal Ben-Dor, Auteur Année de publication : 2022 Article en page(s) : pp 610 - 620 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] analyse de groupement
[Termes IGN] autocorrélation spatiale
[Termes IGN] contamination
[Termes IGN] distribution spatiale
[Termes IGN] image infrarouge
[Termes IGN] interpolation spatiale
[Termes IGN] krigeage
[Termes IGN] plomb
[Termes IGN] qualité du sol
[Termes IGN] République TchèqueRésumé : (auteur) For decades, the Příbram district in the Czech Republic has been affected by industrial and mining activities, which are the main sources of heavy metal pollutants and negatively affect soil quality. A recent study examined visible–near-infrared (VNIR), shortwave-infrared (SWIR), and X-ray fluorescence (XRF) spectroscopy to model soil lead (Pb) content in a selected area located in Příbram. Following that study, and using the data, we examined the spatial distribution of Pb content in the soil, with a combination of traditional techniques (Moran’s I, hotspot analysis, and Kriging). One of the novel points of this work is the use of the Getis–Ord hotspot analysis before the execution of Kriging interpolation to better emphasize clustering patterns. The results indicated that Pb was a spatially dependent soil property and through extensive in-situ sampling, it was possible to generate an accurate interpolation model. The high-Pb hotspots coincided with topographic obstacles that were modeled using topographic profiles extracted from Google Earth, indicating that Pb content does not always exhibit a direct relationship with topographic height as a result of runoff, due to the contribution of topographic steps. This observation provides a new perspective on the relationship between Pb content and topographic patterns. Numéro de notice : A2022-872 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/19475705.2022.2039786 Date de publication en ligne : 23/02/2022 En ligne : https://doi.org/10.1080/19475705.2022.2039786 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102166
in Geomatics, Natural Hazards and Risk > vol 13 (2022) . - pp 610 - 620[article]Vegetation changes in the understory of nitrogen-sensitive temperate forests over the past 70 years / Marina Roth in Forest ecology and management, vol 503 (January-1 2022)
[article]
Titre : Vegetation changes in the understory of nitrogen-sensitive temperate forests over the past 70 years Type de document : Article/Communication Auteurs : Marina Roth, Auteur ; Anja Müller-Meissner, Auteur ; Hans-Gerhard Michiels, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : n° 119754 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse diachronique
[Termes IGN] azote
[Termes IGN] Bade-Wurtemberg (Allemagne)
[Termes IGN] changement climatique
[Termes IGN] détection de changement
[Termes IGN] écosystème forestier
[Termes IGN] forêt tempérée
[Termes IGN] impact sur l'environnement
[Termes IGN] placette d'échantillonnage
[Termes IGN] pollution atmosphérique
[Termes IGN] sous-étage
[Vedettes matières IGN] Ecologie forestièreRésumé : (auteur) Since the industrial revolution, atmospheric nitrogen deposition has increased strongly and has been shown to alter nitrogen cycles, species composition and diversity in many ecosystems, including forests. At the same time, nitrogen removal from forests through biomass extraction via historical management techniques has decreased considerably. A proven tool to analyze the effects of long-term environmental changes are vegetation resurveys. In this study, we tested whether environmental changes resulting from atmospheric nitrogen deposition and altered forest management are reflected in the vegetation composition of temperate forest understories in six acidophilic and oligo-mesophilic forest types in south-western Germany. We compared historical surveys from 1950 to 1976 with surveys from 2017/18 and examined changes in the vegetation using NMDS ordinations and Ellenberg indicator values. While an increase in the number of nitrophilic species was detected in all forest types, only the acidophytic and oligotrophic Vaccinio-Abietetum and Luzulo-Quercetum forests (dominated by Abies alba (Mill.) and Quercus spec., respectively) exhibited a replacement of oligotrophic species by nitrophilic species, amounting to an overall trend of eutrophication. Despite the uncertainties resulting from different plot locations and the slow dynamics of forests, we demonstrate a significant trend in the understory vegetation composition, which is likely caused by atmospheric N deposition. Differences in the sensitivity of different forest types indicate an influence of geological and climatic site characteristics and historical land use on the effects of environmental changes. Numéro de notice : A2022-013 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1016/j.foreco.2021.119754 Date de publication en ligne : 21/10/2021 En ligne : https://doi.org/10.1016/j.foreco.2021.119754 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99070
in Forest ecology and management > vol 503 (January-1 2022) . - n° 119754[article]Extensification and afforestation of cultivated mineral soil for climate change mitigation in Finland / Boris Tupek in Forest ecology and management, vol 501 (December-1 2021)
[article]
Titre : Extensification and afforestation of cultivated mineral soil for climate change mitigation in Finland Type de document : Article/Communication Auteurs : Boris Tupek, Auteur ; Aleski Lehtonen, Auteur ; Raisa Mäkipää, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 119672 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] afforestation
[Termes IGN] Betula (genre)
[Termes IGN] boisement artificiel
[Termes IGN] changement d'occupation du sol
[Termes IGN] dioxyde de carbone
[Termes IGN] écologie forestière
[Termes IGN] Finlande
[Termes IGN] modèle de croissance végétale
[Termes IGN] Picea abies
[Termes IGN] puits de carbone
[Termes IGN] reboisement
[Termes IGN] surface cultivée
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) Offsetting nation-wide CO2 emissions by carbon sinks from land use change (LUC), e.g. agricultural fields extensification and afforestation, is considered as a major climate change mitigation option. We evaluated the LUC potential for reducing emissions and creating annual soil and ecosystem carbon sinks in Finland. We used agricultural statistics, the forest growth model MOTTI, the soil carbon model Yasso07, and the RCP8.5 climate scenario. The soil carbon stock (SOC) of extensified grasslands showed on average less carbon loss than cropland, thus reducing future carbon emissions by LUC between 0.17 Mg ha−1 y-1, initially, and 0.08 Mg ha−1 y-1 after 50 years. The annual rate of such carbon gain was in comparison to SOC between 1.4‰ and 0.7‰ which is lower than proposed by the Paris 4‰ initiative for offsetting global anthropogenic CO2 emissions. Furthermore, after afforestation, estimated SOC is expected to increase above pre-LUC levels with 30 years lag. Estimated SOC sink from afforestation when compared to continuous cultivation varied depending on dominant tree species and soil fertility from between 0.19 Mg ha−1 y-1 (1.7‰ for spruce in medium fertile soil) to 0.46 Mg ha−1 y-1 (3.7‰ for silver birch in highly fertile soil). Future total soil and biomass carbon sink attributed to afforestation ranged between 1.65 and 2.44 Mg ha−1 y-1. Combined carbon sinks created by the present LUC could with 30 years lag offset annually between 0.01 and 4% of the present national net CO2 emissions in Finland. The long delay and a small scale of potential future carbon emission reduction by the LUC highlighted the importance of employing additional tools to reach the national neutrality targets due in next 15 or 30 years. Numéro de notice : A2021-744 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1016/j.foreco.2021.119672 Date de publication en ligne : 22/09/2021 En ligne : https://doi.org/10.1016/j.foreco.2021.119672 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98685
in Forest ecology and management > vol 501 (December-1 2021) . - n° 119672[article]Surface modelling of forest aboveground biomass based on remote sensing and forest inventory data / Xiaofang Sun in Geocarto international, vol 36 n° 14 ([01/08/2021])PermalinkEstimation of biomass increase and CUE at a young temperate scots pine stand concerning drought occurrence by combining eddy covariance and biometric methods / Paulina Dukat in Forests, vol 12 n° 7 (July 2021)PermalinkThe Loop Effect: how climate change impacts the mitigation potential of the French forest sector / Philippe Delacote in Journal of Forest Economics, vol 36 n° 3 ([01/06/2021])PermalinkChemical interaction between Quercus pubescens and its companion species is not emphasized under drought stress / H. Hashoum in European Journal of Forest Research, vol 140 n° 2 (April 2021)PermalinkCloud detection from paired CrIS water vapor and CO₂ channels using machine learning techniques / Miao Tian in IEEE Transactions on geoscience and remote sensing, vol 59 n° 4 (April 2021)PermalinkApports de la télédétection au calcul d’indicateurs agri-environnementaux au service de la PAC, des agriculteurs et porteurs d’enjeu / Christian Bockstaller in Innovations Agronomiques, vol 83 (Mars 2021)PermalinkSearch for top‐down and bottom‐up drivers of latitudinal trends in insect herbivory in oak trees in Europe / Elena Valdés-Correcher in Global ecology and biogeography, vol 30 n° 3 (March 2021)PermalinkApport de la télédétection pour la simulation spatialisée des composantes du bilan carbone des cultures et des effets d'atténuation biogéochimiques et biogéophysiques des cultures intermédiaires / Gaétan Pique (2021)PermalinkA machine learning framework for estimating leaf biochemical parameters from its spectral reflectance and transmission measurements / Bikram Koirala in IEEE Transactions on geoscience and remote sensing, vol 58 n° 10 (October 2020)PermalinkAnalysis of chlorophyll concentration in potato crop by coupling continuous wavelet transform and spectral variable optimization / Ning Liu in Remote sensing, vol 12 n° 17 (September-1 2020)Permalink