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Modelling potential density of natural regeneration of European oak species (Quercus robur L., Quercus petraea (Matt.) Liebl.) depending on the distance to the potential seed source: Methodological approach for modelling dispersal from inventory data at forest enterprise level / Maximilian Axer in Forest ecology and management, vol 482 ([15/02/2021])
[article]
Titre : Modelling potential density of natural regeneration of European oak species (Quercus robur L., Quercus petraea (Matt.) Liebl.) depending on the distance to the potential seed source: Methodological approach for modelling dispersal from inventory data at forest enterprise level Type de document : Article/Communication Auteurs : Maximilian Axer, Auteur ; Robert Schlicht, Auteur ; Sven Wagner, Auteur Année de publication : 2021 Article en page(s) : n° 118802 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] conversion forestière
[Termes IGN] dispersion
[Termes IGN] inventaire forestier étranger (données)
[Termes IGN] Pinophyta
[Termes IGN] planification
[Termes IGN] Quercus pedunculata
[Termes IGN] Quercus sessiliflora
[Termes IGN] régénération (sylviculture)
[Termes IGN] régression par quantile
[Termes IGN] Saxe (Allemagne)
[Termes IGN] semis (sylviculture)
[Vedettes matières IGN] ForesterieRésumé : (auteur) The use of natural oak regeneration from admixed oaks and neighbouring oak stands provides an interesting alternative to cost-intensive artificial oak regeneration when aiming for forest conversion of pure coniferous stands. In this study analysis of forest inventory data is done on how far and in what density natural regeneration of both Pedunculate and Sessile oak occurs in coniferous stands. In order to investigate as exclusively as possible the effect of distance to the seed source on the regeneration density of both oaks, the regeneration potential was determined by using quantile regression. By applying a .995th quantile, reducing factors on seedling density, e.g. desiccation, browsing, pathogens or limited resource availability, were excluded as much as possible. Thus, the effect of zoochorus vectors on effective dispersal could be quantified. The regeneration potential was determined based on data from the forest inventory of the Saxony state forest enterprise, Germany, including 2357 sample plots. Remote sensing data, including the location of oaks in the overstorey, were used to determine the distance to the nearest potential seed source. The results of the present study demonstrate that the highest regeneration densities are not found in the immediate vicinity of the nearest seed source, but at distances between 60 and 140 m to it,i.e. the maximum of seedling density per area unit is in some distance to the trees trunk. In the present study, dispersal distances of established regeneration up to 1565 m were detected. From a distance of 1570–2300 m on, there was no oak regeneration. The results prove that acorns are taken from the seed source and that, in addition to barochorus dispersal, the zoochorus dispersal is of great importance for the succession of coniferous stands. The position of potential seed sources is therefore an important information for silvicultural planning, in order to estimate potential oak regeneration densities. Numéro de notice : A2021-228 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1016/j.foreco.2020.118802 Date de publication en ligne : 13/12/2020 En ligne : https://doi.org/10.1016/j.foreco.2020.118802 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97208
in Forest ecology and management > vol 482 [15/02/2021] . - n° 118802[article]An evaluation of multi-species empirical tree mortality algorithms for dynamic vegetation modelling / Timothy Thrippleton in Scientific reports, vol 11 (2021)
[article]
Titre : An evaluation of multi-species empirical tree mortality algorithms for dynamic vegetation modelling Type de document : Article/Communication Auteurs : Timothy Thrippleton, Auteur ; Lisa Hülsmann, Auteur ; Maxime Cailleret, Auteur ; Harald Bugmann, Auteur Année de publication : 2021 Article en page(s) : n° 19845 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Abies alba
[Termes IGN] Betula pendula
[Termes IGN] dynamique de la végétation
[Termes IGN] Europe (géographie politique)
[Termes IGN] Fagus sylvatica
[Termes IGN] forêt ancienne
[Termes IGN] modélisation de la forêt
[Termes IGN] mortalité
[Termes IGN] Picea abies
[Termes IGN] Pinus sylvestris
[Termes IGN] Quercus sessiliflora
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) Tree mortality is key for projecting forest dynamics, but difficult to portray in dynamic vegetation models (DVMs). Empirical mortality algorithms (MAs) are often considered promising, but little is known about DVM robustness when employing MAs of various structures and origins for multiple species. We analysed empirical MAs for a suite of European tree species within a consistent DVM framework under present and future climates in two climatically different study areas in Switzerland and evaluated their performance using empirical data from old-growth forests across Europe. DVM projections under present climate showed substantial variations when using alternative empirical MAs for the same species. Under climate change, DVM projections showed partly contrasting mortality responses for the same species. These opposing patterns were associated with MA structures (i.e. explanatory variables) and occurred independent of species ecological characteristics. When comparing simulated forest structure with data from old-growth forests, we found frequent overestimations of basal area, which can lead to flawed projections of carbon sequestration and other ecosystem services. While using empirical MAs in DVMs may appear promising, our results emphasize the importance of selecting them cautiously. We therefore synthesize our insights into a guideline for the appropriate use of empirical MAs in DVM applications. Numéro de notice : A2021-964 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1038/s41598-021-98880-2 Date de publication en ligne : 06/10/2021 En ligne : http://dx.doi.org/10.1038/s41598-021-98880-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100136
in Scientific reports > vol 11 (2021) . - n° 19845[article]Long-term tree species population dynamics in Swiss forest reserves influenced by forest structure and climate / Amanda S. Mathys in Forest ecology and management, vol 481 (February 2021)
[article]
Titre : Long-term tree species population dynamics in Swiss forest reserves influenced by forest structure and climate Type de document : Article/Communication Auteurs : Amanda S. Mathys, Auteur ; P. Brang, Auteur ; J. Stillhard, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 118666 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Abies alba
[Termes IGN] Acer pseudoplatanus
[Termes IGN] analyse diachronique
[Termes IGN] changement climatique
[Termes IGN] diamètre à hauteur de poitrine
[Termes IGN] dynamique de la végétation
[Termes IGN] écosystème forestier
[Termes IGN] Fagus sylvatica
[Termes IGN] Fraxinus excelsior
[Termes IGN] inventaire forestier étranger (données)
[Termes IGN] mortalité
[Termes IGN] Pinus sylvestris
[Termes IGN] Quercus (genre)
[Termes IGN] réserve forestière
[Termes IGN] structure d'un peuplement forestier
[Termes IGN] Suisse
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) Changes in tree species composition can have strong effects on ecosystem functioning and the services provided by forests. Empirical observations can provide an improved understanding of the drivers of species population dynamics, yet long-term datasets are scarce in natural forests. This study used inventory data of the Swiss forest reserve network to assess tree population dynamics over the past 60 years. Tree status, species and dbh were repeatedly measured between 1956 and 2018 in 211 permanent plots of 34 forest reserves that covered a wide environmental gradient. Differences in species richness and tree density were compared between the first and last inventory. Furthermore, we used generalized linear mixed effect models to estimate the processes of ingrowth and tree mortality of seven abundant species (Abies alba, Acer pseudoplatanus, Fagus sylvatica, Fraxinus excelsior, Picea abies, Pinus sylvestris and Quercus spp.) separately as a function of stand structural attributes and climate. We found a general decline in the density of the dominant species, with a low recruitment of light-demanding species and an increase in species richness, particularly in the colline vegetation zone. Both species-specific ingrowth and tree mortality were influenced by stand density and climate variables. Tree mortality increased with live tree density and increasing temperature. Ingrowth increased with tree density and decreased with higher temperature. Therefore, forest structural properties and climate have a strong influence on species population dynamics, and both are essential for predicting ingrowth and tree mortality in forest ecosystems. Numéro de notice : A2021-224 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1016/j.foreco.2020.118666 Date de publication en ligne : 28/10/2020 En ligne : https://doi.org/10.1016/j.foreco.2020.118666 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97199
in Forest ecology and management > vol 481 (February 2021) . - n° 118666[article]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 PermalinkInteractions between oak and cervids during the process of forest regeneration / Julien Barrere (2021)PermalinkIs 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)PermalinkRange-wide demographic patterns in European forests along climatic marginality gradients : An approach using national forest inventories / Alexandre Changenet (2021)PermalinkThe strong and the stronger: The effects of increasing ozone and nitrogen dioxide concentrations in pollen of different forest species / Sónia Pereira in Forests, vol 12 n° 1 (January 2021)PermalinkClimate sensitive single tree growth modeling using a hierarchical Bayes approach and integrated nested Laplace approximations (INLA) for a distributed lag model / Arne Nothdurft in Forest ecology and management, vol 478 ([15/12/2020])PermalinkCompetition overrides climate as trigger of growth decline in a mixed Fagaceae Mediterranean rear-edge forest / Alvaro Rubio-Cuadrado in Annals of Forest Science, vol 77 n° 4 (December 2020)PermalinkIs field-measured tree height as reliable as believed – Part II, A comparison study of tree height estimates from conventional field measurement and low-cost close-range remote sensing in a deciduous forest / Luka Jurjević in ISPRS Journal of photogrammetry and remote sensing, vol 169 (November 2020)PermalinkAtmospheric pathways and distance range analysis of castanea pollen transport in Southern Spain / Rocio López-Orozco in Forests, vol 11 n° 10 (October 2020)PermalinkChloroplast haplotypes of Northern red oak (Quercus rubra L.) stands in Germany suggest their origin from Northeastern Canada / Jeremias Götz in Forests, vol 11 n° 9 (September 2020)PermalinkClimate–growth relationships at the transition between Fagus sylvatica and Pinus mugo forest communities in a Mediterranean mountain / Chiara Calderano in Annals of Forest Science, vol 77 n° 3 (September 2020)PermalinkEcology and management of northern red oak (Quercus rubra L. syn. Q. borealis F. Michx.) in Europe: a review / Valeriu-Norocel Nicolescu in Forestry, an international journal of forest research, vol 93 n° 4 (July 2020)PermalinkDecreasing stand density favors resistance, resilience, and recovery of Quercus petraea trees to a severe drought, particularly on dry sites / Anna Schmitt in Annals of Forest Science, Vol 77 n° 2 (June 2020)PermalinkLack of effect of admixture proportion and tree density on water acquisition depth for European beech (Fagus sylvatica L.) and sycamore maple (Acer pseudoplatanus L.) / Alexandre Fruleux in Annals of Forest Science, Vol 77 n° 2 (June 2020)PermalinkStand growth and structure of mixed-species and monospecific stands of Scots pine (Pinus sylvestris L.) and oak (Q. robur L., Quercus petraea (MATT.) LIEBL.) analysed along a productivity gradient through Europe / Hans Pretzsch in European Journal of Forest Research, vol 139 n° 3 (June 2020)PermalinkYear-to-year crown condition poorly contributes to ring width variations of beech trees in French ICP level I network / Clara Tallieu in Forest ecology and management, Vol 465 (1st June 2020)PermalinkIncorporating landscape character in cork oak forest expansion in Sardinia: constraint or opportunity? / I.N. Vogiatzakis in Forests, vol 11 n° 5 (May 2020)PermalinkGenetic variation of introduced red oak (Quercus rubra) stands in Germany compared to North American populations / Tim Pettenkofer in European Journal of Forest Research, vol 139 n° 2 (April 2020)PermalinkCan mixed pine forests conserve understory richness by improving the establishment of understory species typical of native oak forests? / Daphne Lopez-Marcos in Annals of Forest Science, Vol 77 n° 1 (March 2020)PermalinkEffects of Quercus rubra L. on soil properties and humus forms in 50-year-old and 80-year-old forest stands of Lombardy plain / Chiara Ferré in Annals of Forest Science, Vol 77 n° 1 (March 2020)Permalink