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When tree rings behave like foam : moderate historical decrease in the mean ring density of common beech paralleling a strong historical growth increase / Jean-Daniel Bontemps in Annals of Forest Science, Vol 70 n° 4 (June 2013)
[article]
Titre : When tree rings behave like foam : moderate historical decrease in the mean ring density of common beech paralleling a strong historical growth increase Type de document : Article/Communication Auteurs : Jean-Daniel Bontemps , Auteur ; Pierre Gelhaye, Auteur ; Gérard Nepveu, Auteur ; Jean-Christophe Hervé (1961-2017) , Auteur Année de publication : 2013 Article en page(s) : pp 329 - 343 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse diachronique
[Termes IGN] croissance des arbres
[Termes IGN] dendrologie
[Termes IGN] dendrométrie
[Termes IGN] densité du bois
[Termes IGN] estimation statistique
[Termes IGN] Fagus sylvatica
[Termes IGN] puits de carbone
[Vedettes matières IGN] BotaniqueRésumé : (auteur) Context : While historical increases in forest growth have been largely documented, investigations on historical wood density changes remain anecdotic. They suggest possible density decreases in softwoods and ring-porous hardwoods, but are lacking for diffuse-porous hardwoods.
Aims : To evaluate the historical change in mean ring density of common beech, in a regional context where a ring-porous hardwood and a softwood have been studied, and assess the additional effect of past historical increases in radial growth (+50 % over 100 years), resulting from the existence of a positive ring size–density relationship in broadleaved species.
Methods : Seventy-four trees in 28 stands were sampled in Northeastern France to accurately separate developmental stage and historical signals in ring attributes. First, the historical change in mean ring density at 1.30 m (X-ray microdensitometry) was estimated statistically, at constant developmental stage and ring width. The effect of past growth increases was then added to assess the net historical change in wood density.
Results : A progressive centennial decrease in mean ring density of −55 kg m−3 (−7.5 %) was identified (−10 % following the most recent decline). The centennial growth increase induced a maximum +25 kg m−3 increase in mean ring density, whose net variation thus remained negative (−30 kg m−3).
Conclusions : This finding of a moderate but significant decrease in wood density that exceeds the effect of the positive growth change extends earlier reports obtained on other wood patterns in a same regional context and elsewhere. Despite their origin not being understood, such decreases hence form an issue for forest carbon accounting.Numéro de notice : A2013-828 Affiliation des auteurs : LIF+Ext (2012-2019) Thématique : FORET Nature : Article DOI : 10.1007/s13595-013-0263-2 Date de publication en ligne : 21/02/2013 En ligne : https://doi.org/10.1007/s13595-013-0263-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83727
in Annals of Forest Science > Vol 70 n° 4 (June 2013) . - pp 329 - 343[article]Growth-competition-based stem diameter and volume modeling for tree-level forest inventory using airborne LiDAR data / Chien-Shun Lo in IEEE Transactions on geoscience and remote sensing, vol 51 n° 4 Tome 2 (April 2013)
[article]
Titre : Growth-competition-based stem diameter and volume modeling for tree-level forest inventory using airborne LiDAR data Type de document : Article/Communication Auteurs : Chien-Shun Lo, Auteur ; Chinsu Lin, Auteur Année de publication : 2013 Article en page(s) : pp 2216 - 2226 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] croissance des arbres
[Termes IGN] données lidar
[Termes IGN] estimation statistique
[Termes IGN] hauteur des arbres
[Termes IGN] inventaire forestier (techniques et méthodes)
[Termes IGN] modélisation spatiale
[Termes IGN] télémétrie laser aéroporté
[Termes IGN] tronc
[Termes IGN] volume (grandeur)Résumé : (Auteur) An individual tree within a forest stand will have its height and diameter growth restricted by the influence of neighboring trees. This is because trees in close proximity compete for resources and space to enable growth. In this paper, the position of trees, tree height (LH), tree crown radius (LCR), and growth competition index (LCI) were extracted from a light-detection-and-ranging (LiDAR)-based rasterized canopy height model using the multilevel morphological active-contour algorithm. The diameter and volume of individual trees are tested and validated to be an exponential function of those LiDAR-derived tree parameters. The best LiDAR-based diameter estimation model and volume estimation model were tested as significant with an R2 value of 0.84 and 0.9 and evaluated with an estimation bias of 8.7 cm and 0.9m3, respectively. Results also showed that LH and LCR are positively related to the LiDAR-derived diameter at breast height (DBH) and the LiDAR-derived volume of individual trees in a forest stand, whereas LCI is negatively related. The proposed algorithm of individual tree volume estimation was further applied to predict the volume of three sample plots in mountainous forest stands. It was found that the LVM could be used to predict an acceptable volume estimate of old-aged forest stands. The estimation bias, i.e., percentage RMSE (RMSE%), is averaged at around 4% using the LiDAR metrics lnLH, LCI, and LCR, whereas the RMSE% increases to 50% if only lnLH is applied. Results suggest that LCI is an important regulation factor in the estimation of forest volume stocks using LiDAR remote sensing. Numéro de notice : A2013-223 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2012.2211023 En ligne : https://doi.org/10.1109/TGRS.2012.2211023 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32361
in IEEE Transactions on geoscience and remote sensing > vol 51 n° 4 Tome 2 (April 2013) . - pp 2216 - 2226[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-2013041B RAB Revue Centre de documentation En réserve L003 Disponible Shifts in the height-related competitiveness of tree species following recent climate warming and implications for tree community composition: the case of common beech and sessile oak as predominant broadleaved species in Europe / Jean-Daniel Bontemps in Oikos, vol 121 n° 8 (August 2012)
[article]
Titre : Shifts in the height-related competitiveness of tree species following recent climate warming and implications for tree community composition: the case of common beech and sessile oak as predominant broadleaved species in Europe Type de document : Article/Communication Auteurs : Jean-Daniel Bontemps , Auteur ; Jean-Christophe Hervé (1961-2017) , Auteur ; Pierre Duplat, Auteur ; Jean-François Dhôte, Auteur Année de publication : 2012 Article en page(s) : pp 1287 - 1299 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] changement climatique
[Termes IGN] facteur édaphique
[Termes IGN] Fagus sylvatica
[Termes IGN] hauteur des arbres
[Termes IGN] placette d'échantillonnage
[Termes IGN] précipitation
[Termes IGN] Quercus sessiliflora
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) Height growth is a trait that contributes to tree species fitness. How height growth responds to environmental changes may therefore provide indications on species ability to compete and maintain, and on changes in tree community composition. Common beech Fagus sylvatica and sessile oak Quercus petraea are the predominant late-successional broadleaved species in Europe, and they differ in their shade-tolerance. On common beech (a shade tolerant species), recent observations across Europe have shown a growth decline during recent climate warming. Because sessile oak is a warmth- and light-demanding species, we therefore hypothesised that it may gain in competitiveness relative to common beech.
We conducted analyses of historical height growth in several regions spanning the distributional range of the two species across a temperate-continental gradient in France. Common beech and sessile oak were sampled in two and four regions, respectively, and were compared in two neighbouring regions. We documented the climatic and nutritional conditions of regional samples. Height growth of 408 trees of various ages was reconstituted from stem analyses. We estimated 20th-century regional chronologies of height growth using a statistical modelling approach that filtered out the effects of ontogeny and site fertility. In regions where both species were sampled, modelled height trajectories were compared at different periods over the 20th century.
Growth chronologies revealed 1) long-term growth rate increases of a magnitude of 50–100% over 100 years in both species, more acute in the continental domain, 2) recurrent historical inversions in growth fluctuations between species, 3) a recent divergence, with growth decline in common beech versus a dramatic growth increase in sessile oak, more acute in colder regions. The analysis of height trajectories indicated a recent reduction in common beech competitiveness relative to sessile oak. In the face of future climate warming, we conclude that increased prevalence of beech–oak mixtures may arise.Numéro de notice : A2012-716 Affiliation des auteurs : IFN+Ext (1958-2011) Thématique : FORET Nature : Article DOI : 10.1111/j.1600-0706.2011.20080.x Date de publication en ligne : 13/07/2012 En ligne : http://dx.doi.org/10.1111/j.1600-0706.2011.20080.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83721
in Oikos > vol 121 n° 8 (August 2012) . - pp 1287 - 1299[article]A non-asymptotic sigmoid growth curve for top height growth in forest stands / Jean-Daniel Bontemps in Forestry, an international journal of forest research, vol 85 n° 3 (July 2012)
[article]
Titre : A non-asymptotic sigmoid growth curve for top height growth in forest stands Type de document : Article/Communication Auteurs : Jean-Daniel Bontemps , Auteur ; Pierre Duplat, Auteur Année de publication : 2012 Article en page(s) : pp 353 - 368 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Statistiques
[Termes IGN] courbe
[Termes IGN] croissance des arbres
[Termes IGN] hauteur des arbres
[Termes IGN] modèle de croissance végétale
[Termes IGN] modélisation de la forêt
[Termes IGN] peuplement forestierRésumé : (Auteur) Since the height horizon remains undetected in the vast majority of height series sampled in forest stands, even of notable ages, the realism of the traditional asymptotic-size modelling assumption is questioned. The aims of the study were to present an original non-asymptotic growth model and to test its accuracy against asymptotic-size equations. The equation proposed is a first-order four-parameter autonomous differential equation. The related sigmoid size curve has a parabolic branch of time. It was tested on 349 old growth series of top height (1047 stem analyses) selected to explore the maximum observed ranges of age and site conditions in seven temperate tree species growing in pure and even-aged stands. The fitting accuracy of this equation and three classical asymptotic-size growth equations (Richards, Hossfeld IV and Korf equations) were compared, with parameterizations of increasing flexibility. For the different parameterizations, the proposed growth equation showed higher performances than asymptotic growth equations, attributed to its non-asymptotic property and to the mathematical independence between parameters related to the inflection point and late growth. Top height growth was therefore accurately modelled by a sigmoid curve not based on the asymptotic-size assumption. This equation may be of general relevance to tree growth modelling. Numéro de notice : A2012-732 Affiliation des auteurs : non IGN Thématique : FORET/MATHEMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1093/forestry/cps034 Date de publication en ligne : 11/04/2012 En ligne : https://doi.org/10.1093/forestry/cps034 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91172
in Forestry, an international journal of forest research > vol 85 n° 3 (July 2012) . - pp 353 - 368[article]Classification of savanna tree species, in the Greater Kruger National Park region, by integrating hyperspectral and LiDAR data in a Random Forest data mining environment / Laven Naidoo in ISPRS Journal of photogrammetry and remote sensing, vol 69 (April 2012)
[article]
Titre : Classification of savanna tree species, in the Greater Kruger National Park region, by integrating hyperspectral and LiDAR data in a Random Forest data mining environment Type de document : Article/Communication Auteurs : Laven Naidoo, Auteur ; Moses Azong Cho, Auteur ; Renaud Mathieu, Auteur ; et al., Auteur Année de publication : 2012 Article en page(s) : pp 167 - 179 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] Afrique du sud (état)
[Termes IGN] arbre (flore)
[Termes IGN] classification par forêts d'arbres décisionnels
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] hauteur des arbres
[Termes IGN] image hyperspectrale
[Termes IGN] lasergrammétrie
[Termes IGN] parc naturel national
[Termes IGN] savaneRésumé : (Auteur) The accurate classification and mapping of individual trees at species level in the savanna ecosystem can provide numerous benefits for the managerial authorities. Such benefits include the mapping of economically useful tree species, which are a key source of food production and fuel wood for the local communities, and of problematic alien invasive and bush encroaching species, which can threaten the integrity of the environment and livelihoods of the local communities. Species level mapping is particularly challenging in African savannas which are complex, heterogeneous, and open environments with high intra-species spectral variability due to differences in geology, topography, rainfall, herbivory and human impacts within relatively short distances. Savanna vegetation are also highly irregular in canopy and crown shape, height and other structural dimensions with a combination of open grassland patches and dense woody thicket – a stark contrast to the more homogeneous forest vegetation. This study classified eight common savanna tree species in the Greater Kruger National Park region, South Africa, using a combination of hyperspectral and Light Detection and Ranging (LiDAR)-derived structural parameters, in the form of seven predictor datasets, in an automated Random Forest modelling approach. The most important predictors, which were found to play an important role in the different classification models and contributed to the success of the hybrid dataset model when combined, were species tree height; NDVI; the chlorophyll b wavelength (466 nm) and a selection of raw, continuum removed and Spectral Angle Mapper (SAM) bands. It was also concluded that the hybrid predictor dataset Random Forest model yielded the highest classification accuracy and prediction success for the eight savanna tree species with an overall classification accuracy of 87.68% and KHAT value of 0.843. Numéro de notice : A2012-199 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2012.03.005 En ligne : https://doi.org/10.1016/j.isprsjprs.2012.03.005 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31646
in ISPRS Journal of photogrammetry and remote sensing > vol 69 (April 2012) . - pp 167 - 179[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 081-2012031 SL Revue Centre de documentation Revues en salle Disponible Potential of an ultraviolet, medium-footprint lidar prototype for retrieving forest structure / Tristan Allouis in ISPRS Journal of photogrammetry and remote sensing, vol 66 n° 6 supplement (December 2011)PermalinkMulti-level filtering segmentation to measure individual tree parameters based on Lidar data: Application to a mountainous forest with heterogeneous stands / Cédric Vega in International journal of applied Earth observation and geoinformation, vol 13 n° 4 (August 2011)PermalinkLe lidar, outil performant pour cartographier la hauteur des peuplements forestiers / Jérôme Bock in Rendez-vous techniques, n° 32 (printemps 2011)PermalinkUne base de données unique en France de cubages d’arbres individuels (volumes, biomasses) au service d’une modélisation générique de la ressource en bois énergie / Michaël Rivoire in Revue forestière française, vol 63 n° 2 (2011)PermalinkForestry applications for satellite lidar remote sensing / J. Rosette in Photogrammetric Engineering & Remote Sensing, PERS, vol 77 n° 3 (March 2011)PermalinkFocus : Élaboration des indicateurs de biodiversité de la publication « Les indicateurs de gestion durable des forêts françaises », difficultés et perspectives / Nabila Hamza in Sciences, eaux & territoires, n° 3 ([22/10/2010])Permalinkn° 11 - 01/09/2010 - Actes du colloque "Panorama de la dendrochronologie en France", Digne-les-Bains, 8-10 octobre 2009 (Bulletin de Collection EDYTEM. cahiers de géographie) / Laurent AstradePermalinkPredicting southeastern forest canopy heights and fire fuel models using GLAS data / M. Ashworth in Photogrammetric Engineering & Remote Sensing, PERS, vol 76 n° 8 (August 2010)PermalinkRecent changes in forest productivity: An analysis of national forest inventory data for common beech (Fagus sylvatica L.) in north-eastern France / Marie Charru in Forest ecology and management, vol 260 n° 5 (30 July 2010)PermalinkLa canopée forestière vue par un Lidar ultra-violet aéroporté de nouvelle génération / J. Cuesta in Revue Française de Photogrammétrie et de Télédétection, n° 191 (Mai 2010)Permalink