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Self-thinning tree mortality models that account for vertical stand structure, species mixing and climate / David I. Forrester in Forest ecology and management, Vol 487 ([01/05/2021])
[article]
Titre : Self-thinning tree mortality models that account for vertical stand structure, species mixing and climate Type de document : Article/Communication Auteurs : David I. Forrester, Auteur ; Thomas G. Backer, Auteur ; Stephen R. Elms, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 118936 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Abies alba
[Termes IGN] Australie
[Termes IGN] auto-éclaircie
[Termes IGN] changement climatique
[Termes IGN] Chine
[Termes IGN] dépérissement
[Termes IGN] Eucalyptus nitens
[Termes IGN] Fagus sylvatica
[Termes IGN] modèle de croissance végétale
[Termes IGN] mortalité
[Termes IGN] peuplement forestier
[Termes IGN] peuplement mélangé
[Termes IGN] Picea abies
[Termes IGN] Pinus sylvestris
[Termes IGN] Quercus pedunculata
[Termes IGN] Quercus sessiliflora
[Termes IGN] structure de la végétation
[Termes IGN] Suisse
[Vedettes matières IGN] SylvicultureRésumé : (auteur) Self-thinning dynamics are often considered when managing stand density in forests and are used to constrain forest growth models. However, self-thinning relationships are often quantified using only data at a conceptualised self-thinning line, even though self-thinning can begin before the stand actually reaches a self-thinning line. Also, few self-thinning relationships account for the effects of species composition in mixed-species forests, and stand structure such as relative height of species (in mixtures), and/or size or age cohorts in uneven-aged forests. Such considerations may be important given the effects of global climate change and interest in mixed-species and uneven-aged forests. The objective of this study was to develop self-thinning relationships based on changes in the tree density relative to mean tree diameter, instead of focusing only on data for state variables (e.g. tree density) at the self-thinning line. This was done while also considering how the change in tree density is influenced by site quality and stand structure (species composition and relative height). The relationships were modelled using data from temperate Australian Eucalyptus plantations (436 plots), subtropical forests in China (88 plots), and temperate forests in Switzerland (1055 plots). Zero-inflated and hurdle generalized linear models with Poisson and negative binomial distributions were fit for several species, as well as for all-species equations. The intercepts and slopes of the self-thinning lines were higher than many published studies which may have resulted from both the less restrictive equation form and data selection. The rates of self-thinning often decreased as the proportion of the object species increased, as relative height increased (species or size cohort became more dominant), and as site (quality) index increased. The effects of aridity varied between species, with self-thinning increasing with aridity index for Abies alba, Pinus sylvestris, Quercus petraea and Quercus robur, but decreasing with aridity index for Eucalyptus nitens, Fagus sylvatica and Picea abies as sites became wetter and cooler. Self-thinning model parameters were not correlated with species traits, including specific leaf area, wood basic density or crown diameter – stem diameter allometry. All-species self-thinning relationships based on all data could be adjusted using a correction factor for rarer species where there were insufficient data to develop species-specific equations. The approach and equations developed could be used in forest growth models to calculate how the tree density declines as mean tree size increases, as height changes relative to other cohorts or species, as species proportions change, and as climatic and edaphic conditions change. Numéro de notice : A2021-355 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1016/j.foreco.2021.118936 Date de publication en ligne : 18/02/2021 En ligne : https://doi.org/10.1016/j.foreco.2021.118936 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97612
in Forest ecology and management > Vol 487 [01/05/2021] . - n° 118936[article]Modeling size-density trajectories of even-aged ash (Fraxinus excelsior L.) stands in France. A baseline to assess the impact of Chalara ash dieback / Noël Le Goff in Annals of Forest Science, vol 78 n° 1 (March 2021)
[article]
Titre : Modeling size-density trajectories of even-aged ash (Fraxinus excelsior L.) stands in France. A baseline to assess the impact of Chalara ash dieback Type de document : Article/Communication Auteurs : Noël Le Goff, Auteur ; François Ningre, Auteur ; Jean-Marc Ottorini, Auteur Année de publication : 2021 Article en page(s) : n° 3 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] densité de la végétation
[Termes IGN] dépérissement
[Termes IGN] éclaircie (sylviculture)
[Termes IGN] foresterie
[Termes IGN] France (administrative)
[Termes IGN] Fraxinus excelsior
[Termes IGN] Fungi
[Termes IGN] maladie phytosanitaire
[Termes IGN] modèle de croissance végétale
[Termes IGN] mortalité
[Vedettes matières IGN] SylvicultureRésumé : (auteur) Key message: A piecewise polynomial function already used to represent the size-density trajectories of pure even-aged stands of beech, oak, and Douglas-fir proved its ability to represent the size-density trajectories of a new species, ash. The widespread ash dieback caused departures from the expected size-density trajectories. These abnormalities can be used to detect an extra level of mortality due to infection by Hymenoscyphus fraxineus in pure even-aged ash stands.
Context: The size-density trajectories allow quantifying more precisely the density of stands and can help the forest manager to decide of the opportunity of thinnings. This study helped to quantify extra mortality in pure even-aged stands by using the size-density trajectories established for stands evolving at maximum density.
Aims: This study was conducted to establish size-density trajectories of pure even-aged ash stands and compare them with those recently established for beech and oak in France, in particular concerning the onset of density-dependent (regular) mortality. The additional effect of ash dieback on mortality was also an issue.
Material and methods: We used permanent and semi-permanent unthinned ash plots installed in the north of France and where inventories of trees were performed at more or less regular intervals: measurements included tree status (dead or alive) and diameter or girth at breast height for all trees and total height for a sample of living trees. The size-density trajectories of plots describing the course of the number of living trees in relation with the mean stand girth, in logarithmic scales, were modeled with a piecewise polynomial function fitted with a mixed-effects model. A permanent sample of trees was also selected for ash dieback and extra mortality monitoring.
Results: The piecewise polynomial function already used proved its ability to represent the size-density trajectories of even-aged ash stands of various initial densities and fertility levels. As for beech and oak, the trajectories were modeled so that mortality onset occurred at a constant relative density. This level appeared to be much higher for ash (RDI = 0.58), revealing that ash survived with less growing space than beech and oak and appeared to be more efficient. Ash dieback caused an additional mortality in the experimental ash stands studied, and this excess of mortality appeared predictable on the basis of observed departures from the expected size-density trajectories.
Conclusion: A single parameter function family could be used to predict the size-density trajectories of even-aged ash stands, on the basis of the results obtained previously on oak and beech. Mortality onset and space requirements of ash could be compared with those of beech and oak and show that ash can survive at higher densities and is a more efficient species. Predicted size-density trajectories proved also useful to detect and quantify the excess of mortality due to H. fraxineus on ash. This approach could be extended to other diseases and species with predictable size-density trajectories.Numéro de notice : A2021-475 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s13595-020-01005-4 Date de publication en ligne : 07/01/2021 En ligne : https://doi.org/10.1007/s13595-020-01005-4 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97095
in Annals of Forest Science > vol 78 n° 1 (March 2021) . - n° 3[article]Contrasting responses of habitat conditions and insect biodiversity to pest- or climate-induced dieback in coniferous mountain forests / Jérémy Cours in Forest ecology and management, vol 482 ([15/02/2021])
[article]
Titre : Contrasting responses of habitat conditions and insect biodiversity to pest- or climate-induced dieback in coniferous mountain forests Type de document : Article/Communication Auteurs : Jérémy Cours, Auteur ; Laurent Larrieu, Auteur ; Carlos Lopez-Vaamonde, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 118811 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Abies alba
[Termes IGN] biodiversité
[Termes IGN] bois mort
[Termes IGN] dépérissement
[Termes IGN] dynamique de la végétation
[Termes IGN] exploitation forestière
[Termes IGN] forêt alpestre
[Termes IGN] habitat forestier
[Termes IGN] insecte nuisible
[Termes IGN] mortalité
[Termes IGN] Picea abies
[Termes IGN] Pinophyta
[Vedettes matières IGN] SylvicultureRésumé : (auteur) Natural disturbances are major drivers of forest dynamics. However, in the current context of anthropogenic global warming, shifts in disturbance regimes are expected. Natural disturbances usually leave biological or structural legacies which are important for early-successional species. Nevertheless, these legacies are usually eliminated by forest managers through salvage logging. Here, we investigated the consequences of forest dieback and the following salvage logging on both forest habitat conditions and saproxylic beetle communities. We conducted our study in two types of conifer-dominated highland forests: Pyrenean silver fir (Abies alba) which has suffered drought-induced dieback and Bavarian Norway spruce (Picea abies) which has suffered bark beetle-induced (Ips typographus) dieback. In both of the forest contexts, dieback provided a biological legacy through an increase in deadwood resources; however, this increase was much greater in the spruce forests. Nonetheless, despite this increase in resources, neither type of forest gained in total abundance or species richness after disturbance, compared to healthy stands. Nevertheless, the species composition of saproxylic beetle composition was significantly affected by dieback in spruce stands, but not in the silver fir forests. In the spruce plots, saproxylic beetles responded positively to the large increase in deadwood in the declining stands, including a very strong positive response from red-listed species. Saproxylic beetle assemblages in spruce forests were mainly drove by canopy openness and deadwood amount. In the silver fir plots, we did not observed responses from the saproxylic beetle communities to deadwood amount increase. This lack of response may be explained by the relatively low amount of deadwood generated by the drought-induced dieback. Concerning salvage logging, it caused stronger contrasts in spruce forests than in silver fir forests, where it generally had no significant impact. For example, in spruce forests, salvage logging reduced the density of large snags by 91% and large logs by 87% compared with unharvested declining plots. Most of the significant environmental effects on biodiversity associated with dieback were no longer significant after accounting for the salvaged plots in our study data. Then, forest dieback and salvage logging induced much sharper and stronger effects on environmental and community metrics in the spruce than in the silver fir forests. The contrast between Bavaria and the French Pyrenees seems partly related to dieback severity. Finally, we invite forest managers to conserve biological and structural legacies through patches of deadwood-rich areas. Numéro de notice : A2021-227 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1016/j.foreco.2020.118811 Date de publication en ligne : 04/12/2020 En ligne : https://doi.org/10.1016/j.foreco.2020.118811 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97207
in Forest ecology and management > vol 482 [15/02/2021] . - n° 118811[article]
Titre : Diagnostics of Plant Diseases Type de document : Monographie Auteurs : Dmitry Kurouski, Éditeur scientifique Editeur : London [UK] : IntechOpen Année de publication : 2021 ISBN/ISSN/EAN : 978-1-83962-516-9 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] blé (céréale)
[Termes IGN] image captée par drone
[Termes IGN] maladie phytosanitaire
[Termes IGN] Oryza (genre)
[Termes IGN] spectroscopie
[Termes IGN] surveillance agricoleIndex. décimale : 35.41 Applications de télédétection - végétation Résumé : (Editeur) Digital farming is an approach to farming in which crop yield is maximized while environmental impact is minimized. Integral to this approach is diagnostic sensing of plant disease and stress. This book examines innovative sensing technology such as satellite- and unmanned aerial vehicle (UAV)-based RGB and thermography imaging as well as hyperspectral, infrared, reflectance and Raman spectroscopy. Note de contenu :
1. Application of Spectroscopic Techniques in Early Detection of Fungal Plant Pathogens
By Ritesh Kumar, Shikha Pathak, Nishant Prakash, Upasna Priya and Abhijeet Ghatak
2. Diagnosis of Fungal Plant Pathogens Using Conventional and Molecular Approaches
By Monika C. Dayarathne, Amin U. Mridha and Yong Wang
3. UAV Remote Sensing: An Innovative Tool for Detection and Management of Rice Diseases
By Xin-Gen Zhou, Dongyan Zhang and Fenfang Lin
4. Blister Blight Disease of Tea: An Enigma
By Chayanika Chaliha and Eeshan Kalita
5. Spectroscopy Technology: An Innovative Tool for Diagnosis and Monitoring of Wheat Diseases
By Fenfang Lin, Dongyan Zhang, Xin-Gen Zhou and Yu Lei
6. The Trends in the Evaluation of Fusarium Wilt of Chickpea
By Chandan Singh and Deepak VyasNuméro de notice : 26721 Affiliation des auteurs : non IGN Thématique : BIODIVERSITE/FORET/IMAGERIE Nature : Recueil / ouvrage collectif DOI : 10.5772/intechopen.88565 Date de publication en ligne : 07/07/2021 En ligne : https://doi.org/10.5772/intechopen.88565 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99502 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 Is Xylella fastidiosa a serious threat to European forests? / Marie-Laure Desprez-Loustau in Forestry, an international journal of forest research, vol 94 n° 1 (January 2021)PermalinkQualification des données LiDAR GEDI pour le suivi de l’impact climatique sur la forêt de Südharz / Iris Jeuffrard (2021)PermalinkSuivi des vignes par télédétection de proximité : le deep learning au service de l’agriculture de précision / Sami Beniaouf (2021)PermalinkThe Impact of ash dieback on veteran trees in Southwestern Sweden / Vikki Bengtsson in Baltic forestry, vol 27 n° 1 ([01/01/2021])Permalink3D reconstruction of internal wood decay using photogrammetry and sonic tomography / Junjie Zhang in Photogrammetric record, vol 35 n° 171 (September 2020)PermalinkApplying multi-temporal Landsat satellite data and Markov-cellular automata to predict forest cover change and forest degradation of sundarban reserve forest, Bangladesh / Mohammad Emran Hasan in Forests, vol 11 n° 9 (September 2020)PermalinkA century of National Forest Inventory in Norway – informing past, present, and future decisions / Johannes Breidenbach in Forest ecosystems, vol 7 (2020)PermalinkDetection of Xylella fastidiosa infection symptoms with airborne multispectral and thermal imagery: Assessing bandset reduction performance from hyperspectral analysis / T. Poblete in ISPRS Journal of photogrammetry and remote sensing, vol 162 (April 2020)PermalinkPermalinkPermalink