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Radiative transfer modeling in structurally complex stands: towards a better understanding of parametrization / Frédéric André in Annals of Forest Science, vol 78 n° 4 (December 2021)
[article]
Titre : Radiative transfer modeling in structurally complex stands: towards a better understanding of parametrization Type de document : Article/Communication Auteurs : Frédéric André, Auteur ; Louis de Wergifosse, Auteur ; François de Coligny, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 92 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Belgique
[Termes IGN] couvert forestier
[Termes IGN] croissance des arbres
[Termes IGN] densité du feuillage
[Termes IGN] diamètre à hauteur de poitrine
[Termes IGN] estimation bayesienne
[Termes IGN] Fagus sylvatica
[Termes IGN] houppier
[Termes IGN] Leaf Mass per Area
[Termes IGN] modèle de croissance végétale
[Termes IGN] modèle de transfert radiatif
[Termes IGN] peuplement mélangé
[Termes IGN] photosynthèse
[Termes IGN] production primaire brute
[Termes IGN] production primaire nette
[Termes IGN] Quercus sessiliflora
[Termes IGN] structure d'un peuplement forestier
[Vedettes matières IGN] ForesterieRésumé : (auteur) Key message: The best options to parametrize a radiative transfer model change according to the response variable used for fitting. To predict transmitted radiation, the turbid medium approach performs much better than the porous envelop, especially when accounting for the intra-specific variations in leaf area density but crown shape has limited effects. When fitting with tree growth data, the porous envelop approach combined with the more complex crown shape provides better results. When using a joint optimization with both variables, the better options are the turbid medium and the more detailed approach for describing crown shape and leaf area density.
Context: Solar radiation transfer is a key process of tree growth dynamics in forest.
Aims: Determining the best options to parametrize a forest radiative transfer model in heterogeneous oak and beech stands from Belgium.
Methods: Calibration and evaluation of a forest radiative transfer module coupled to a spatially explicit tree growth model were repeated for different configuration options (i.e., turbid medium vs porous envelope to calculate light interception by trees, crown shapes of contrasting complexity to account for their asymmetry) and response variables used for fitting (transmitted radiation and/or tree growth data).
Results: The turbid medium outperformed the porous envelope approach. The more complex crown shapes enabling to account for crown asymmetry improved performances when including growth data in the calibration.
Conclusion: Our results provide insights on the options to select when parametrizing a forest radiative 3D-crown transfer model depending on the research or application objectives.Numéro de notice : A2021-768 Affiliation des auteurs : non IGN Thématique : FORET/MATHEMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s13595-021-01106-8 Date de publication en ligne : 26/10/2021 En ligne : https://doi.org/10.1007/s13595-021-01106-8 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99010
in Annals of Forest Science > vol 78 n° 4 (December 2021) . - n° 92[article]Forest type matters: Global review about the structure of oak dominated old-growth temperate forests / Janos Bölöni in Forest ecology and management, vol 500 (November-15 2021)
[article]
Titre : Forest type matters: Global review about the structure of oak dominated old-growth temperate forests Type de document : Article/Communication Auteurs : Janos Bölöni, Auteur ; Réka Aszalos, Auteur ; Tamas Frank, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 119629 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] bois mort
[Termes IGN] densité du peuplement
[Termes IGN] diamètre à hauteur de poitrine
[Termes IGN] forêt ancienne
[Termes IGN] forêt sèche
[Termes IGN] forêt tempérée
[Termes IGN] gestion forestière durable
[Termes IGN] peuplement forestier
[Termes IGN] Quercus (genre)
[Termes IGN] service écosystémique
[Termes IGN] structure d'un peuplement forestier
[Termes IGN] surface terrière
[Vedettes matières IGN] SylvicultureRésumé : (auteur) The structure and composition of temperate old-growth oak forests are reviewed based on 108 case studies about 175 stands. The stands were classified as dry, dry-mesic and mesic forest types and the variables (density, basal area, size distribution, dead wood volume) were compared among them. Compared to the global range of this forest type, the United States was overrepresented, while West and Central Asia, Europe and Central America were underrepresented. In mesic oak forests the basal area and density of large trees were higher than in dry stands, while tree density and sapling density were lower. The proportion of oaks in tree and sapling layers were the highest in dry and lowest in mesic forests. The size distribution of trees followed negative exponential or rotated sigmoid types. In dry habitats all size categories are dominated by oaks, while in mesic type, only large ones followed the same trend. The volume of dead wood and the proportion of downed dead wood increased along the humidity gradient. In stands with repeated measurements, basal area and relative density of oaks decreased in the last decades. The understanding of the structure and composition of temperate old-growth oak forests is necessary for their restoration and application of close to nature forestry principles. Numéro de notice : A2021-740 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1016/j.foreco.2021.119629 Date de publication en ligne : 02/09/2021 En ligne : https://doi.org/10.1016/j.foreco.2021.119629 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98641
in Forest ecology and management > vol 500 (November-15 2021) . - n° 119629[article]A CNN-based approach for the estimation of canopy heights and wood volume from GEDI waveforms / Ibrahim Fayad in Remote sensing of environment, vol 265 (November 2021)
[article]
Titre : A CNN-based approach for the estimation of canopy heights and wood volume from GEDI waveforms Type de document : Article/Communication Auteurs : Ibrahim Fayad, Auteur ; Dino Lenco, Auteur ; Nicolas Baghdadi, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 112652 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] Brésil
[Termes IGN] classification par réseau neuronal convolutif
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] Eucalyptus (genre)
[Termes IGN] forme d'onde
[Termes IGN] Global Ecosystem Dynamics Investigation lidar
[Termes IGN] hauteur des arbres
[Termes IGN] modèle de croissance végétale
[Termes IGN] semis de points
[Termes IGN] volume en boisRésumé : (auteur) Full waveform (FW) LiDAR systems have proven their effectiveness to map forest biophysical variables in the last two decades, owing to their ability of measuring, with high accuracy, forest vertical structures. The Global Ecosystem Dynamics Investigation (GEDI) system on board the International Space Station (ISS) is the latest FW spaceborne LiDAR instrument for the continuous observation of Earth's forests. FW systems rely on very sophisticated pre-processing steps to generate a priori metrics in order to leverage their capabilities for the accurate estimation of the aforementioned forest characteristics. The ever-expanding volume of acquired GEDI data, which to date comprises more than 25 billion acquired unfiltered shots, and along with the pre-processed data, amounting to more than 90 TB of data, raises new challenges in terms of adapted preprocessing methods for the suitable exploitation of such a huge and complex amount of LiDAR data. To overcome the issues related to the generation of relevant metrics from GEDI data, we propose a new metric-free approach to estimate canopy dominant heights (Hdom) and wood volume (V) of Eucalyptus plantations over five different regions in Brazil. To avoid metric computation, we leverage deep learning techniques and, more in detail, convolutional neural networks with the aim to analyze the GEDI Level 1B geolocated waveforms. Performance comparisons were conducted between four convolutional neural network (CNN) variants using GEDI waveform data (either untouched, or subsetted) and a metric based Random Forest regressor (RF). Additionally, we tested if our framework can improve the generalization of the models to different distant regions. First, the models were trained using data from all the study regions. Cross validated results showed that the CNN based models compared well against their RF counterpart for both Hdom and V. The RMSE on the estimation of Hdom from the CNN based models varied between 1.54 and 1.94 m with a coefficient of determination (R2) between 0.86 and 0.91, while the RF model produced an accuracy on Hdom estimates of 1.45 m (R2 = 0.92). For V, CNN based estimations ranged from 27.76 to 33.33 m3.ha−1 (R2 between 0.82 and 0.88), while for RF, the RMSE was 27.61 m3.ha−1 (R2 = 0.88). Next, model generalization was assessed by means of a spatial transfer experiment. For Hdom, both the CNN and RF approaches showed similar performances to a global model, however, the CNN based approach showed higher variability on the estimation accuracy, and the variability was related to the forest structure between the trained and tested data (similar tree heights yield better accuracies). For the estimation of V, considering both approaches, the accuracy was dependent on the allometric relationship between Hdom and V in the training and testing regions while lower accuracies on V were obtained when the testing and training regions exhibited a different allometric relationship. Numéro de notice : A2021-869 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.1016/j.rse.2021.112652 Date de publication en ligne : 31/08/2021 En ligne : https://doi.org/10.1016/j.rse.2021.112652 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99118
in Remote sensing of environment > vol 265 (November 2021) . - n° 112652[article]Growth recovery and phenological responses of juvenile beech (fagus sylvatica L.) exposed to spring warming and late spring frost / Kristine Vander Mijnsbrugge in Forests, vol 12 n° 11 (November 2021)
[article]
Titre : Growth recovery and phenological responses of juvenile beech (fagus sylvatica L.) exposed to spring warming and late spring frost Type de document : Article/Communication Auteurs : Kristine Vander Mijnsbrugge, Auteur ; Jessa May Malanguis, Auteur ; Stefaan Moreels, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 1604 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Belgique
[Termes IGN] chaleur
[Termes IGN] croissance des arbres
[Termes IGN] dommage forestier causé par facteurs naturels
[Termes IGN] Fagus sylvatica
[Termes IGN] gelée
[Termes IGN] phénologie
[Termes IGN] phénomène climatique extrême
[Termes IGN] semis (sylviculture)
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) Global change increases the risk of extreme climatic events. The impact of extreme temperature may depend on the tree species and also on the provenance. Ten provenances of Fagus sylvatica L. were grown in a common garden environment in Belgium and subjected to different temperature treatments. Half of the one year old seedlings were submitted to a high thermal stress in the spring of the first year, and all plants were exposed to a late spring frost in the second year. The high-temperature treated plants displayed reduced growth in the first year, which was fully compensated (recovery with exact compensation) in the second year for radial growth and in the third year for height growth. Frost in the spring of the second year damaged part of the saplings and reduced their growth. The frost damaged plants regained the pre-stress growth rate one year later (recovery without compensation). The high temperature treatment in the first year and the frost damage in the second year clearly influenced the phenological responses in the year of the event and in the succeeding year. Little population differentiation was observed among the provenances for growth and for phenological responses. Yet, a southern provenance, a non-autochthonous provenance (original German provenance that was planted in Belgium about a century ago) and a more continental provenance flushed earlier than the local Atlantic provenances in the year of the frost event, resulting in more frost damage. Some caution should therefore be taken when translocating provenances as an anticipation of the predicted climate warming. Numéro de notice : A2021-879 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.3390/f12111604 Date de publication en ligne : 20/11/2021 En ligne : https://doi.org/10.3390/f12111604 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99169
in Forests > vol 12 n° 11 (November 2021) . - n° 1604[article]Multi-sensor aboveground biomass estimation in the broadleaved hyrcanian forest of Iran / Ghasem Ronoud in Canadian journal of remote sensing, vol 47 n° 6 ([01/11/2021])
[article]
Titre : Multi-sensor aboveground biomass estimation in the broadleaved hyrcanian forest of Iran Titre original : Estimation multi-capteurs de la biomasse aérienne de la forêt de feuillus hyrcanienne d’Iran Type de document : Article/Communication Auteurs : Ghasem Ronoud, Auteur ; Parviz Fatehi, Auteur ; Ali Asghar Darvishsefat, Auteur Année de publication : 2021 Article en page(s) : pp 818 - 834 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] biomasse aérienne
[Termes IGN] classification barycentrique
[Termes IGN] classification par forêts d'arbres décisionnels
[Termes IGN] estimation statistique
[Termes IGN] Fagus orientalis
[Termes IGN] image Landsat-8
[Termes IGN] image Sentinel-MSI
[Termes IGN] image Sentinel-SAR
[Termes IGN] Iran
[Termes IGN] régression multiple
[Vedettes matières IGN] Inventaire forestierMots-clés libres : Support Vector Regression Résumé : (auteur) In this study, the capability of Landsat-8 (L8), Sentinel-2 (S2), Sentinel-1 (S1), and their combination was investigated for estimating aboveground biomass (AGB). A pure stand of Fagus Orientalis located in the Hyrcanian forest of Iran was selected as the study area. The performance of a parametric approach, i.e., Multiple Linear Regression (MLR) model and non-parametric approaches, i.e., k-Nearest Neighbor (k-NN), Random Forest (RF), and Support Vector Regression (SVR), were also evaluated for AGB estimations. Our results indicated that among S2 metrics, the FAPAR canopy biophysical index and NDVI index based on the red-edge band (NIR-b8a) have the highest correlation coefficient (r) of 0.420 and 0.417, respectively. The results of AGB estimation showed that a combination of S2 and S1 datasets using the k-NN algorithm had the best accuracy (R2 of 0.57 and rRMSE of 14.68%). The best rRMSE using L8, S2, and S1 datasets was 18.95, 16.99, and 19.17% using k-NN, k-NN, and MLR algorithms, respectively. The combination of L8 with S1 dataset also improved the rRMSE relative to L8 and S1 separately by 0.96 and 1.18%, respectively. We concluded that the combination of optical data (L8 or S2) with SAR data (S1) improves the broadleaved Hyrcanian AGB estimation. Numéro de notice : A2021-956 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE/MATHEMATIQUE Nature : Article DOI : 10.1080/07038992.2021.1968811 Date de publication en ligne : 07/09/2021 En ligne : https://doi.org/10.1080/07038992.2021.1968811 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99982
in Canadian journal of remote sensing > vol 47 n° 6 [01/11/2021] . - pp 818 - 834[article]A novel cotton mapping index combining Sentinel-1 SAR and Sentinel-2 multispectral imagery / Lan Xun in ISPRS Journal of photogrammetry and remote sensing, Vol 181 (November 2021)PermalinkEarly detection of pine wilt disease using deep learning algorithms and UAV-based multispectral imagery / Run Yu in Forest ecology and management, vol 497 (October-1 2021)PermalinkThe effects of combining the variables in allometric biomass models on biomass estimates over large forest areas: A european beech case study / Erick O. Osewe in Forests, vol 12 n° 10 (October 2021)PermalinkUncertainties in measurements of leaf optical properties are small compared to the biological variation within and between individuals of European beech / Fanny Petibon in Remote sensing of environment, vol 264 (October 2021)PermalinkVariation in downed deadwood density, biomass, and moisture during decomposition in a natural temperate forest / Tomas Přívětivý in Forests, vol 12 n° 10 (October 2021)PermalinkAssessing the land expectation value of even-aged vs coppice-with-standards stand management and long-term effects of whole-tree harvesting on forest productivity and profitability / Abdelwahad Bessaad in Annals of Forest Science, vol 78 n° 3 (September 2021)PermalinkDetection of aspen in conifer-dominated boreal forests with seasonal multispectral drone image point clouds / Alwin A. Hardenbol in Silva fennica, vol 55 n° 4 (September 2021)PermalinkGeoglam, l'agriculture par satellite / Laurent Polidori in Géomètre, n° 2194 (septembre 2021)PermalinkForest inventory-based assessments of the invasion risk of Pseudotsuga menziesii (Mirb.) Franco and Quercus rubra L. in Germany / A. Bindewald in European Journal of Forest Research, vol 140 n° 4 (August 2021)PermalinkThe influence of fencing on seedling establishment during reforestation of oak stands: a comparison of artificial and natural regeneration techniques including costs / Magnus Löf in European Journal of Forest Research, vol 140 n° 4 (August 2021)Permalink