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Titre : Drivers and implications of dominant and rare tree species in global forests Type de document : Thèse/HDR Auteurs : Iris Hordijk, Auteur Editeur : Zurich : Eidgenossische Technische Hochschule ETH - Ecole Polytechnique Fédérale de Zurich EPFZ Année de publication : 2021 Note générale : bibliographie
Thesis submitted to attain the degree of Doctor of Sciences of ETH ZurichLangues : Anglais (eng) Descripteur : [Termes IGN] âge du peuplement forestier
[Termes IGN] biodiversité végétale
[Termes IGN] biome
[Termes IGN] écosystème forestier
[Termes IGN] espèce végétale
[Termes IGN] extinction (biologie)
[Termes IGN] forêt boréale
[Termes IGN] forêt tempérée
[Termes IGN] forêt tropicale
[Termes IGN] habitat (nature)
[Termes IGN] peuplement forestier
[Termes IGN] plante menacée
[Termes IGN] productivité biologique
[Termes IGN] richesse floristique
[Termes IGN] service écosystémique
[Vedettes matières IGN] Inventaire forestierIndex. décimale : THESE Thèses et HDR Résumé : (auteur) Forests provide crucial ecosystem functions and services for the earth system and humanity. Due to ongoing deforestation and forest degradation, these ecosystems are increasingly fragmented and disturbed, significantly changing tree species composition within the forest. Most plant communities are comprised of a few dominant species that are numerically abundant, and many rare species, each of which exist at low abundance. Given their differences in abundance and characteristics, the loss of dominant and rare species have distinct impacts on ecosystem functioning. Decreasing abundances of dominant species typically have larger immediate impacts on overall ecosystem processes (e.g. productivity), while a decline in abundance of rare species can lead to the loss of key functions and overall multifunctionality, and can ultimately drive species extinctions. Despite their unique role in the ecosystem, it remains unclear what drives species to become dominant or rare, how threatened locally dominant and rare species are, and what the effect of species abundance on ecosystem function is across large environmental gradients in our global forests. The aim of this thesis is to explore the drivers of tree species abundance, and evaluate the effect of relative tree species abundance on forest productivity. Specifically, the three chapters of this thesis aimed to identify at a global scale the 1) patterns, drivers, and threats to dominant and rare tree species, 2) differences in trait values and trait diversity that differentiate the functional contributions of dominant and rare tree species, and 3) how evenness (the relative species abundances in the community) mediates the relationship between tree species richness and forest productivity in forests. In this thesis I answered these research questions by analyzing a global dataset of forest composition, which enabled me to describe broad-scale ecological patterns and to test general ecological laws. Note de contenu : General introduction
1- Patterns, drivers and threats to dominant and rare tree species worldwide
2- Trait diversity of dominant and rare tree species in global forests: a habitat filtering perspective
3- Evenness mediates the global relationship between forest productivity and richness
SynthesisNuméro de notice : 28690 Affiliation des auteurs : non IGN Thématique : BIODIVERSITE/FORET Nature : Thèse étrangère Note de thèse : PhD Thesis : Sciences : ETH Zurich 2021 DOI : sans En ligne : https://www.research-collection.ethz.ch/handle/20.500.11850/520710 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100131 Effects of different site preparation methods on the root development of planted Quercus petraea and Pinus nigra / Mathieu Dassot in New forests, vol 52 n° 1 (January 2021)
[article]
Titre : Effects of different site preparation methods on the root development of planted Quercus petraea and Pinus nigra Type de document : Article/Communication Auteurs : Mathieu Dassot , Auteur ; Catherine Collet, Auteur Année de publication : 2021 Article en page(s) : pp 17 - 30 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] phytobiologie
[Termes IGN] Pinus nigra
[Termes IGN] plantation forestière
[Termes IGN] Quercus sessiliflora
[Termes IGN] système radiculaire
[Vedettes matières IGN] BotaniqueRésumé : (auteur) Mechanical site preparation (MSP) is often performed prior to planting to improve the growth and survival of planted seedlings. In this study, we compared root development of 5-years-old Quercus petraea and Pinus nigra seedlings planted in plots that had been prepared with different methods, i.e. deep scarification, deep scarification combined with mounding-subsoiling, herbicide and a control without preparation. Seventy-two trees were excavated (36 per species) and their root system was measured by recording points in a three-dimensional space along their roots. The variation of the number of roots with depth and distance to root collar was assessed and analysed, as well as the root projection area. Our results showed that root development was better in the plots with mechanical preparation, for both Q. petraea and P. nigra, when compared to the control. Combining mounding to subsoiling made the roots extending deeper, especially for Q. petraea. A strong relationship was found between root projection area and root collar diameter, indicating the primary effect of lateral root spread on tree growth. The herbicide treatment induced the highest root growth, which raised questions about the potential negative effects of changes in soil properties caused by MSP methods. Numéro de notice : A2021-965 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s11056-020-09781-7 En ligne : http://dx.doi.org/10.1007/s11056-020-09781-7 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101352
in New forests > vol 52 n° 1 (January 2021) . - pp 17 - 30[article]Ensemble learning methods on the space of covariance matrices : application to remote sensing scene and multivariate time series classification / Sara Akodad (2021)
Titre : Ensemble learning methods on the space of covariance matrices : application to remote sensing scene and multivariate time series classification Type de document : Thèse/HDR Auteurs : Sara Akodad, Auteur ; Christian Germain, Directeur de thèse ; Lionel Bombrun, Directeur de thèse Editeur : Bordeaux : Université de Bordeaux Année de publication : 2021 Importance : 220 p. Format : 21 x 30 cm Note générale : bibliographie
Thèse présentée pour obtenir le grade de Docteur de l'Université de Bordeaux, Spécialité Automatique, Productique, Signal et Image, Ingénierie cognitiqueLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image mixte
[Termes IGN] analyse multivariée
[Termes IGN] Castanea sativa
[Termes IGN] classification dirigée
[Termes IGN] classification par réseau neuronal convolutif
[Termes IGN] déformation temporelle dynamique (algorithme)
[Termes IGN] géométrie euclidienne
[Termes IGN] image Sentinel-MSI
[Termes IGN] image Sentinel-SAR
[Termes IGN] maladie phytosanitaire
[Termes IGN] matrice de covariance
[Termes IGN] processus gaussien
[Termes IGN] série temporelle
[Termes IGN] surveillance forestièreIndex. décimale : THESE Thèses et HDR Résumé : (auteur) In view of the growing success of second-order statistics in classification problems, the work of this thesis has been oriented towards the development of learning methods in manifolds. Indeed, covariance matrices are symmetric positive definite matrices that live in a non-Euclidean space. It is therefore necessary to adapt the classical tools of Euclidean geometry to handle this type of data. To do that, we have proposed to exploit the log-Euclidean metric. This latter allows to project the set of covariance matrices on a tangent plane to the manifold defined at a reference point, classically chosen equal to the identity matrix, followed by a vectorization step to obtain the log-Euclidean representation. On this tangent plane, it is possible to define parametric Gaussian models as well as Gaussian mixture models. Nevertheless, this projection on a single tangent plane can induce distortions. In order to overcome this limitation, we have proposed a GMM model composed of several tangent planes, where the reference points are defined by the centers of each cluster.In view of the success of neural networks, in particular convolutional neural networks (CNNs), we have proposed two hybrid transfer learning approaches based on the covariance matrix computed locally and globally on the CNN convolutional layers’ outputs. The local approach relies on the covariance matrices extracted locally on the first layers of a CNN, which are then encoded by the Fisher vectors computed on their log-Euclidean representation, while for the global approach, a single covariance matrix is computed on the feature maps of the CNN deep layers. Moreover, in order to give more importance to the objects of interest present in the images, we proposed to use a covariance matrix weighted by the saliency information. Furthermore, in order to take advantage of both local and global aspects, these two approaches are subsequently combined in an ensemble strategy.On the other hand, the availability of multivariate time series has aroused the interest of the remote sensing community and more generally of machine learning researchers for the development of new learning strategies dedicated to supervised classification. In particular, methods based on the calculation of point-to-point distance between series. Moreover, two series belonging to the same class can evolve in different ways, which can induce temporal distortions (translation, compression, dilation, etc.). To avoid this, warping methods allow to align the time series. In order to extend this approach to time series of covariance matrices, while ensuring invariance to the re-parametrization of the series, we were interested in the TSRVF representation. In the same context, several ensemble methods have been proposed in the literature, including TCK, which relies on similarity computation to classify time series. We have proposed to extend this strategy to covariance matrices by introducing the SO-TCK approach which relies on the log-Euclidean representation of such matrices. Finally, the last axis of this thesis concerns the modeling of temporal trajectories of signals measured by the radar (Sentinel 1) and optical (Sentinel 2) sensors. In particular, we are interested in the forestry problem of the chestnut ink disease in the Montmorency forest. For this purpose, we developed classification and regression models to predict a health status score from the covariance matrix computed on multi-temporal radiometric attributes. Note de contenu : Introduction
1- Riemannian geometry and statistical modeling on the space of Symmetric Positive Definite (SPD) matrices
2- Ensemble learning approaches based on covariance pooling of CNN Features
3- Symmetric positive definite matrix time series classification
4- Forest health monitoring using Sentinel-1 and Sentinel-2 time series
Conclusions and perspectivesNuméro de notice : 28605 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE/MATHEMATIQUE Nature : Thèse française Note de thèse : Thèse de Doctorat : Automatique, Productique, Signal et Image, Ingénierie cognitique : Bordeaux : 2021 Organisme de stage : IMS DOI : sans En ligne : https://tel.hal.science/tel-03484011 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99446
Titre : Étude de l’évolution du couvert forestier dans le Haut-Béarn Type de document : Mémoire Auteurs : Céline Toussaint, Auteur Editeur : Champs-sur-Marne : Ecole nationale des sciences géographiques ENSG Année de publication : 2021 Importance : 81 p. Format : 21 x 30 cm Note générale : Bibliographie
Mémoire de fin d'études, cycle des ingénieurs ENSG 3ème année, Master DDMEG Développement Durable, Management Environnemental et GéomatiqueLangues : Français (fre) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] analyse spatio-temporelle
[Termes IGN] BD forêt
[Termes IGN] BD Topo
[Termes IGN] Béarn
[Termes IGN] carte d'Etat-Major
[Termes IGN] carte de Cassini
[Termes IGN] couvert forestier
[Termes IGN] densité de la végétation
[Termes IGN] données vectorielles
[Termes IGN] image aérienne
[Termes IGN] image Landsat
[Termes IGN] image Sentinel-MSI
[Termes IGN] Normalized Difference Vegetation Index
[Termes IGN] orthoimage géoréférencée
[Termes IGN] peuplement forestier
[Termes IGN] QGISIndex. décimale : DDMEG Mémoires du Master Développement Durable, Management Environnemental et Géomatique Résumé : (Auteur) En Asie de l’Est et en Afrique subsaharienne, la superficie de la forêt régresse, tandis qu’en Europe de l’Est, une augmentation de la surface forestière est constatée depuis le XIXe siècle. Dans le Haut-Béarn, zone montagnarde à faible densité urbaine (environ 7 000 habitants pour 100 000 hectares), cette impression d’envahissement par les arbres est forte parmi la population, depuis le début de l’exode rural et le manque de main d’œuvre pour maintenir les paysages ouverts. C’est dans ce cadre que le sujet de stage « étude de l’évolution du couvert forestier dans le Haut-Béarn » a été proposé par l’Institution Patrimoniale du Haut-Béarn. Pour analyser ces changements, il a été question d’utiliser la télédétection, après avoir vectorisé les forêts sur les cartes d’État-Major, sur d’anciennes photographies aériennes (au préalable géoréférencées) sur le logiciel de SIG QGIS. L’utilisation de données forestières vectorielles, telles que les BD Forêt V1 (1992) et V2 (2008), et la BD Topographique (2019) de l’IGN, a permis d’établir qu’une augmentation d’environ 65 % est observable entre le XIXe siècle et 2019 sur le Haut-Béarn. La classification d’images satellites et le calcul de leur NDVI a enrichi la courbe d’évolution de la forêt sur ce territoire, qui a laissé apparaître une accélération de la progression de la forêt ces dernières années. Au cours de ce stage, des travaux annexes ont également pu être réalisés, comme la préparation de cartes pour des héliportages, ou l’utilisation d’algorithmes pour détecter les zones écobuées de 2021, et ont contribué à ma compréhension des enjeux du territoire des valléens. Note de contenu :
Introduction
1. Présentation et contexte
2. La caractérisation des forêts dans le Haut-Béarn au cours du temps
3. Les résultats et leurs enseignements
4. Travaux annexes principaux réalisés pendant le stage
ConclusionNuméro de notice : 26663 Affiliation des auteurs : non IGN Thématique : FORET/GEOMATIQUE/IMAGERIE Nature : Mémoire de fin d'études IT Organisme de stage : Institution Patrimoniale du Haut-Béarn Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98873 Documents numériques
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Étude de l’évolution du couvert forestier dans le Haut-Béarn - pdf auteurAdobe Acrobat PDF Evaluation of Sentinel-1 & 2 time series for the identification and characterization of ecological continuities, from wooded to crop-dominated landscapes / Audrey Mercier (2021)
Titre : Evaluation of Sentinel-1 & 2 time series for the identification and characterization of ecological continuities, from wooded to crop-dominated landscapes Type de document : Thèse/HDR Auteurs : Audrey Mercier, Auteur ; Laurence Hubert-Moy, Directeur de thèse ; Jacques Baudry, Directeur de thèse Editeur : Rennes : Université de Rennes 2 Année de publication : 2021 Importance : 305 p. Format : 21 x 30 cm Note générale : Bibliographie
Thèse de Doctorat présentée à l'Université de Rennes 2, Spécialité GéomatiqueLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image mixte
[Termes IGN] caractérisation
[Termes IGN] continuité écologique
[Termes IGN] cultures
[Termes IGN] données polarimétriques
[Termes IGN] forêt
[Termes IGN] habitat (nature)
[Termes IGN] image Sentinel-MSI
[Termes IGN] image Sentinel-SAR
[Termes IGN] occupation du sol
[Termes IGN] paysage agricole
[Termes IGN] précision de la classification
[Termes IGN] série temporelle
[Termes IGN] utilisation du solIndex. décimale : THESE Thèses et HDR Résumé : (Auteur) Habitat loss is now considered one of the most serious threats to biodiversity. While many studies have focused on the circulation role of woodland features, very few have focused on the role of ecological continuities within agricultural mosaics. The objectives of this thesis were (1) to assess the combined use of Sentinel 1 and 2 time series to identify and characterize the elements of ecological continuities through land cover classifications and crop characterization in wooded and crop-dominated landscapes and (2) to estimate the impact of the spatio-temporal structuring of these landscape on biodiversity using metrics derived from Sentinel time series. The results showed that although S-2 data are more adapted than S-1 data to discriminate between land cover/land use types in wooded landscapes and phenological stages of wheat and rapeseed in crop-dominated landscapes, the combined use of S-2 and S-1 data improves their accuracy of the classifications, with S-1 data also showing a strong interest in cloudy areas. They also showed the interest of polarimetric indicators derived from S-1 data to characterize wheat and rapeseed crops. Finally, they highlighted the interest of the biophysical heterogeneity metrics derived from S-2 data to accurately estimate the distribution of carabid beetle species. The use of this metric, calculated with free images available everywhere on Earth, continuous and consistent from one site to another and from one type of crop to another,
should contribute to the study of the impact of ecological continuities on biodiversity.Note de contenu : General introduction
1. Ecological continuities from wooded to crop-dominated landscapes
2. The use of remote sensing imagery for the identification and characterization of ecological continuities
3. Study areas and data
4. Evaluation of Sentinel-1 and 2 time Series for land cover classification of forest–agriculture mosaics in temperate and tropical landscapes
5. Evaluation of Sentinel-1 and 2 time series for predicting wheat and rapeseed phenological stages
6. Evaluation of Sentinel-1 and 2 time series for estimating LAI and biomass of wheat and rapeseed crop types
7. Sentinel-2 images bring out functional biophysical heterogeneities in crop mosaics
General conclusion and perspectivesNuméro de notice : 26708 Affiliation des auteurs : non IGN Thématique : BIODIVERSITE/FORET/IMAGERIE Nature : Thèse française Note de thèse : Thèse de Doctorat : Géomatique : Rennes 2 : 2021 Organisme de stage : Littoral, Environnement, Télédétection, Géomatique LETG nature-HAL : Thèse DOI : sans Date de publication en ligne : 14/10/2021 En ligne : https://tel.hal.science/tel-03377565 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99456 Evaluation de la qualité des mesures de croissance pluriannuelles des données d’inventaire forestier national en vue de leur utilisation en monitoring à haute fréquence de la production forestière / Félix Altenhoven (2021)PermalinkEvaluation du stock de carbone aérien dans la végétation à partir de multiples observations satellites micro-ondes / Martin Cubaud (2021)PermalinkExamining the effectiveness of Sentinel-1 and 2 imagery for commercial forest species mapping / Mthembeni Mngadi in Geocarto international, vol 36 n° 1 ([01/01/2021])PermalinkPermalinkForest Products Annual Market Review 2020-2021 / United Nations Economic Commission for Europe (2021)PermalinkFrom local to global: A transfer learning-based approach for mapping poplar plantations at national scale using Sentinel-2 / Yousra Hamrouni in ISPRS Journal of photogrammetry and remote sensing, vol 171 (January 2021)PermalinkPermalinkPermalinkHigh resolution mapping of forest resources and prediction reliability using multisource inventory approach / Ankit Sagar (2021)PermalinkInteractions between oak and cervids during the process of forest regeneration / Julien Barrere (2021)Permalink