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Multi-species individual tree segmentation and identification based on improved mask R-CNN and UAV imagery in mixed forests / Chong Zhang in Remote sensing, vol 14 n° 4 (February-2 2022)
[article]
Titre : Multi-species individual tree segmentation and identification based on improved mask R-CNN and UAV imagery in mixed forests Type de document : Article/Communication Auteurs : Chong Zhang, Auteur ; Jiawei Zhou, Auteur ; Huiwen Wang, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : n° 874 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] Chine
[Termes IGN] classification par réseau neuronal convolutif
[Termes IGN] détection de contours
[Termes IGN] échantillonnage de données
[Termes IGN] entropie
[Termes IGN] estimation quantitative
[Termes IGN] feuillu
[Termes IGN] hauteur des arbres
[Termes IGN] image captée par drone
[Termes IGN] peuplement mélangé
[Termes IGN] Pinophyta
[Termes IGN] segmentation d'imageRésumé : (auteur) High-resolution UAV imagery paired with a convolutional neural network approach offers significant advantages in accurately measuring forestry ecosystems. Despite numerous studies existing for individual tree crown delineation, species classification, and quantity detection, the comprehensive situation in performing the above tasks simultaneously has rarely been explored, especially in mixed forests. In this study, we propose a new method for individual tree segmentation and identification based on the improved Mask R-CNN. For the optimized network, the fusion type in the feature pyramid network is modified from down-top to top-down to shorten the feature acquisition path among the different levels. Meanwhile, a boundary-weighted loss module is introduced to the cross-entropy loss function Lmask to refine the target loss. All geometric parameters (contour, the center of gravity and area) associated with canopies ultimately are extracted from the mask by a boundary segmentation algorithm. The results showed that F1-score and mAP for coniferous species were higher than 90%, and that of broadleaf species were located between 75%–85.44%. The producer’s accuracy of coniferous forests was distributed between 0.8–0.95 and that of broadleaf ranged in 0.87–0.93; user’s accuracy of coniferous was distributed between 0.81–0.84 and that of broadleaf ranged in 0.71–0.76. The total number of trees predicted was 50,041 for the entire study area, with an overall error of 5.11%. The method under study is compared with other networks including U-net and YOLOv3. Results in this study show that the improved Mask R-CNN has more advantages in broadleaf canopy segmentation and number detection. Numéro de notice : A2022-168 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.3390/rs14040874 Date de publication en ligne : 11/02/2022 En ligne : https://doi.org/10.3390/rs14040874 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99793
in Remote sensing > vol 14 n° 4 (February-2 2022) . - n° 874[article]Scorch height and volume modeling in prescribed fires: Effects of canopy gaps in Pinus pinaster stands in Southern Europe / J.R. Molina in Forest ecology and management, vol 506 (February-15 2022)
[article]
Titre : Scorch height and volume modeling in prescribed fires: Effects of canopy gaps in Pinus pinaster stands in Southern Europe Type de document : Article/Communication Auteurs : J.R. Molina, Auteur ; M. Ortega, Auteur ; F. Rodríguez y Silva, Auteur Année de publication : 2022 Article en page(s) : n° 119979 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] brûlis
[Termes IGN] canopée
[Termes IGN] échantillonnage de données
[Termes IGN] Espagne
[Termes IGN] gestion des risques
[Termes IGN] gestion forestière
[Termes IGN] incendie de forêt
[Termes IGN] Pinus pinaster
[Vedettes matières IGN] ForesterieRésumé : (auteur) The use of prescribed fire has been on the rise in recent years owing to its effectiveness in surface fuel reduction, its implementation cost, and the possibility of firefighter training. However, greater knowledge regarding the effects of fire on woodlands is required by forest managers. Scorch height and scorch volume are the most widely used variables for evaluating the effects of burning on trees. This study proposes a scorch height model for the prescribed fires of pine stands in Southern Europe. Although the two main variables of the existing models (fire-line intensity and air temperature) were considered, our model achieved a coefficient of determination of 89% with the incorporation of the canopy base height. A decision tree for scorch volume was also developed using the three independent variables. The presence of canopy gaps in the lower, mid-, and upper slopes resulted in significant differences in the scorch height. The scorch height increased between 0.33 m and 2.08 m because of the canopy gaps in the upper slope. These findings can play an important role in the implementation and improvement of prescribed burn windows. Numéro de notice : A2022-058 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1016/j.foreco.2021.119979 Date de publication en ligne : 24/12/2021 En ligne : https://doi.org/10.1016/j.foreco.2021.119979 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99469
in Forest ecology and management > vol 506 (February-15 2022) . - n° 119979[article]A stand-level growth and yield model for thinned and unthinned even-aged Scots pine forests in Norway / Christian Kuehne in Silva fennica, vol 56 n° 1 (January 2022)
[article]
Titre : A stand-level growth and yield model for thinned and unthinned even-aged Scots pine forests in Norway Type de document : Article/Communication Auteurs : Christian Kuehne, Auteur ; J. Paul McLean, Auteur ; Kobra Maleki, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : n° 1 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] branche (arbre)
[Termes IGN] éclaircie (sylviculture)
[Termes IGN] forêt équienne
[Termes IGN] gestion forestière
[Termes IGN] hauteur des arbres
[Termes IGN] modèle de croissance végétale
[Termes IGN] Norvège
[Termes IGN] Pinus sylvestris
[Termes IGN] rendement
[Termes IGN] surface terrière
[Termes IGN] volume en bois
[Vedettes matières IGN] SylvicultureRésumé : (auteur) Management of Scots pine (Pinus sylvestris L.) in Norway requires a forest growth and yield model suitable for describing stand dynamics of even-aged forests under contemporary climatic conditions with and without the effects of silvicultural thinning. A system of equations forming such a stand-level growth and yield model fitted to long-term experimental data is presented here. The growth and yield model consists of component equations for (i) dominant height, (ii) stem density (number of stems per hectare), (iii) total basal area, (iv) and total stem volume fitted simultaneously using seemingly unrelated regression. The component equations for stem density, basal area, and volume include a thinning modifier to forecast stand dynamics in thinned stands. It was shown that thinning significantly increased basal area and volume growth while reducing competition related mortality. No significant effect of thinning was found on dominant height. Model examination by means of various fit statistics indicated no obvious bias and improvement in prediction accuracy in comparison to existing models in general. An application of the developed stand-level model comparing different management scenarios exhibited plausible long-term behavior and we propose this is therefore suitable for national deployment. Numéro de notice : A2022-171 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.14214/sf.10627 Date de publication en ligne : 26/01/2022 En ligne : https://doi.org/10.14214/sf.10627 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99806
in Silva fennica > vol 56 n° 1 (January 2022) . - n° 1[article]Pourquoi la forêt française a besoin d’un traitement de fond / Guillaume Decocq in The Conversation France, vol 2022 ([10/02/2022])
[article]
Titre : Pourquoi la forêt française a besoin d’un traitement de fond Type de document : Article/Communication Auteurs : Guillaume Decocq, Auteur ; Serge Muller, Auteur Année de publication : 2022 Langues : Français (fre) Descripteur : [Termes IGN] adaptation (biologie)
[Termes IGN] Chalara fraxinea
[Termes IGN] dépérissement
[Termes IGN] essence indigène
[Termes IGN] France (administrative)
[Termes IGN] gestion forestière durable
[Termes IGN] mortalité
[Termes IGN] productivité
[Termes IGN] puits de carbone
[Termes IGN] sécheresse
[Termes IGN] sylviculture
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) Les conclusions des Assises nationales de la forêt et du bois, lancées par le gouvernement en octobre 2021 avec pour objectif de « penser la forêt française de demain », devraient être rendues dans les prochains jours. Un des axes majeurs de cette réflexion concernait le renforcement de la résilience des forêts et la préservation de la biodiversité.
Car la forêt française est aujourd’hui en crise : depuis deux décennies, on assiste en effet à une mortalité croissante des peuplements forestiers et à une baisse globale de leur productivité. Si la surface boisée en France métropolitaine ne cesse de croître depuis le milieu du XIXe siècle, c’est en raison du boisement – spontané ou artificiel – de terres agricoles, car la superficie occupée par des forêts anciennes, elle, ne cesse de diminuer. Ce « dépérissement », est généralement attribué aux modifications climatiques. Les sécheresses estivales récurrentes fragilisent les arbres et la douceur hivernale favorise les pullulations de bioagresseurs, en particulier les scolytes et les hannetons. Le changement climatique en est sans aucun doute une cause essentielle, mais il est aussi le révélateur d’écosystèmes forestiers fragilisés par des décennies de pratiques sylvicoles focalisées sur la production de bois. Non seulement la forêt française fixe moins de carbone par unité de surface, mais l’exploitation des peuplements dépérissants induit des émissions supplémentaires de CO₂ aggravant l’effet de serre et les changements climatiques associés.Numéro de notice : A2022-214 Affiliation des auteurs : non IGN Thématique : BIODIVERSITE/FORET Nature : Article DOI : sans Date de publication en ligne : 20/02/2022 En ligne : https://theconversation.com/pourquoi-la-foret-francaise-a-besoin-dun-traitement- [...] Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100083
in The Conversation France > vol 2022 [10/02/2022][article]The number of tree species on Earth / Roberto Cazzolla Gatti in Proceedings of the National Academy of Sciences of the United States of America PNAS, vol 119 n° 6 (2022)
[article]
Titre : The number of tree species on Earth Type de document : Article/Communication Auteurs : Roberto Cazzolla Gatti, Auteur ; Peter B. Reich, Auteur ; Javier G. P. Gamarra, Auteur ; et al., Auteur ; Olivier Bouriaud , Auteur Année de publication : 2022 Article en page(s) : n° e2115329119 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] distribution spatiale
[Termes IGN] essence d'arbre
[Termes IGN] forêt
[Termes IGN] richesse floristique
[Termes IGN] Terre (planète)
[Vedettes matières IGN] Ecologie forestièreRésumé : (auteur) One of the most fundamental questions in ecology is how many species inhabit the Earth. However, due to massive logistical and financial challenges and taxonomic difficulties connected to the species concept definition, the global numbers of species, including those of important and well-studied life forms such as trees, still remain largely unknown. Here, based on global ground-sourced data, we estimate the total tree species richness at global, continental, and biome levels. Our results indicate that there are ∼73,000 tree species globally, among which ∼9,000 tree species are yet to be discovered. Roughly 40% of undiscovered tree species are in South America. Moreover, almost one-third of all tree species to be discovered may be rare, with very low populations and limited spatial distribution (likely in remote tropical lowlands and mountains). These findings highlight the vulnerability of global forest biodiversity to anthropogenic changes in land use and climate, which disproportionately threaten rare species and thus, global tree richness. Numéro de notice : A2022-155 Affiliation des auteurs : non IGN Thématique : BIODIVERSITE/FORET Nature : Article DOI : 10.1073/pnas.2115329119 Date de publication en ligne : 31/01/2022 En ligne : https://doi.org/10.1073/pnas.2115329119 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100309
in Proceedings of the National Academy of Sciences of the United States of America PNAS > vol 119 n° 6 (2022) . - n° e2115329119[article]Afforestation with Pinus nigra Arn ssp salzmannii along an elevation gradient: controlling factors and implications for climate change adaptation / Manuel Esteban Lucas-Borja in Trees, vol 36 n° 1 (February 2022)PermalinkAn open science and open data approach for the statistically robust estimation of forest disturbance areas / Saverio Francini in International journal of applied Earth observation and geoinformation, vol 106 (February 2022)PermalinkAnalysis of spatio-temporal changes in forest biomass in China / Weiyi Xu in Journal of Forestry Research, vol 33 n° 1 (February 2022)PermalinkDeriving a tree growth model from any existing stand growth model / Quang V. Cao in Canadian Journal of Forest Research, Vol 52 n° 2 (February 2022)PermalinkDiffuse sunlight and cosmic rays: Missing pieces of the forest growth change attribution puzzle? / Jean-Daniel Bontemps in Science of the total environment, vol 806 n°1 (February 2022)PermalinkEuropean-wide forest monitoring substantiate the neccessity for a joint conservation strategy to rescue European ash species (Fraxinus spp.) / Jan-Peter George in Scientific reports, vol 12 (2022)PermalinkFive decades of ground flora changes in a temperate forest: The good, the bad and the ambiguous in biodiversity terms / K.J. Kirby in Forest ecology and management, vol 505 (February-1 2022)PermalinkGenerating 2m fine-scale urban tree cover product over 34 metropolises in China based on deep context-aware sub-pixel mapping network / Da He in International journal of applied Earth observation and geoinformation, vol 106 (February 2022)PermalinkGenome-wide evolutionary response of European oaks during the Anthropocene / Dounia Saleh in Evolution letters, vol 6 n° 1 (February 2022)PermalinkGrowing stock monitoring by European National Forest Inventories: Historical origins, current methods and harmonisation / Thomas Gschwantner in Forest ecology and management, vol 505 (February-1 2022)Permalink