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Is the variability of key wood properties linked with the variability of key architectural traits? Case of planted Teak in Togo regarding thinning and provenance / Kodjo Tondjo in Annals of Forest Science, vol 72 n° 6 (September 2015)  

Public [article]  inAnnals of Forest Science > vol 72 n° 6 (September 2015) . - pp 717 - 729 Titre : Is the variability of key wood properties linked with the variability of key architectural traits? Case of planted Teak in Togo regarding thinning and provenance Type de document : Article/Communication Auteurs : Kodjo Tondjo, Auteur ; Loïc Brancheriau, Auteur ; Sylvie-Annabel Sabatier, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 717 - 729 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Végétation [Termes IGN] analyse diachronique [Termes IGN] Congo [Termes IGN] croissance des arbres [Termes IGN] image proche infrarouge [Termes IGN] Tectona grandis [Termes IGN] Togo Résumé : (auteur) Key message : A retrospective architectural analysis performed on planted teaks in Togo showed that the variation of wood radial properties were linked with tree ontogeny, and that these relationships depended on thinning practices and provenance. Context : Variability in growth, flowering and forking in individual trees according to origin and/or thinning practices may affect wood structure and consequently impact wood physical properties. We tested this hypothesis in teak. Aims : We sought evidence of: (1) origin effects (Togolese versus Tanzanian teak) on growth, flowering, cambial growth and wood properties; (2) thinning effects on these variables and (3) relationships between tree ontogeny and radial variations of wood properties. Methods : A retrospective architectural analysis was used to draw stem growth and near infrared spectroscopy to assess radial variations of wood properties. Results : Flowering reflects tree vigour and began at an earlier age in Togolese than in Tanzanian provenances. No differences were detected in regards to growth ring surface area, basic density and modulus of elasticity. Both systematic and selective thinnings improved growth without impacting the two latter properties. Stabilization of the growth ring area observed at 4 years old was associated with a decline in stem annual extension with a 1-year time lag. Conclusions : Architectural analyses showed that radial growth was linked with tree ontogeny. This method can be extended to subsequent developmental stages, i.e. to older trees with economic interest, and used to determine architectural traits that are useful in tree selection. Numéro de notice : A2015-408 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1007/s13595-014-0425-x Date de publication en ligne : 24/10/2014 En ligne : https://doi.org/10.1007/s13595-014-0425-x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76895 [article]

A novel method to correct for wood MOE ultrasonics and NIRS measurements on increment cores in Liquidambar styraciflua L / Herizo Rakotovololonalimanana in Annals of Forest Science, vol 72 n° 6 (September 2015)  

Public [article]  inAnnals of Forest Science > vol 72 n° 6 (September 2015) . - pp 753 - 761 Titre : A novel method to correct for wood MOE ultrasonics and NIRS measurements on increment cores in Liquidambar styraciflua L Type de document : Article/Communication Auteurs : Herizo Rakotovololonalimanana, Auteur ; Gilles Chaix, Auteur ; Loïc Brancheriau, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 753 - 761 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] analyse comparative [Termes IGN] élasticité [Termes IGN] image proche infrarouge [Termes IGN] Liquidambar styraciflua [Termes IGN] spectrométrie [Termes IGN] télédétection acoustique [Termes IGN] ultrason Résumé : (auteur) Key message : Ultrasounds overestimate the MOE value. This paper analyses the causes of this difference and opens the perspective for a novel method allowing the calculation of the correct MOE from ultrasounds or NIRS measurements on cores. Context : Standardized methods for determining wood modulus of elasticity (MOE) are destructive and require many replicates. Other methods such as NIRS and ultrasound have been developed to characterize wood properties and overcome these constraints. Aim : The aim of this study was to compare the two MOE measurement methods (NIRS and ultrasound) applied to cores of wood taken from standing trees (Liquidambar styraciflua). Methods : MOE, measured by an acoustic method in standard samples (360 × 20 × 20 mm), was used as a reference. Then MOE was predicted by an NIRS model and determined using ultrasound in standard samples (360 × 20 × 20 mm), small samples (10 × 20 × 20 mm), and cores (15 mm in diameter). Result : MOE values determined by acoustic method on standard samples and by ultrasonic method on small samples were correlated (R 2 = 0.72) and were not statistically different. The NIRS PLS regression yielded a model with R 2 cv = 0.80. The link between NIRS and ultrasound on cores was statistically significant (R 2 = 0.68). Conclusion : The ultrasonic technique determines an apparent modulus enables comparative data analysis. This apparent modulus can be used for quantitative analysis if a corrective model is used. A correction formula to ultrasonic MOE was proposed in the case of a prismatic geometry. Numéro de notice : A2015-409 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.1007/s13595-015-0469-6 Date de publication en ligne : 12/03/2015 En ligne : https://doi.org/10.1007/s13595-015-0469-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76896 [article]

Ultrasonic tomography of green wood using a non-parametric imaging algorithm with reflected waves / Loïc Brancheriau in Annals of Forest Science, Vol 65 n° 7 (October - November 2008)  

Public [article]  inAnnals of Forest Science > Vol 65 n° 7 (October - November 2008) . - n° 712 Titre : Ultrasonic tomography of green wood using a non-parametric imaging algorithm with reflected waves Titre original : Tomographie ultrasonore de bois vert par reconstruction d'image non paramétrique en réflexion Type de document : Article/Communication Auteurs : Loïc Brancheriau, Auteur ; Philippe Lasaygues, Auteur ; Eric Debieu, Auteur ; Jean Pierre Lefebvre, Auteur Année de publication : 2008 Article en page(s) : n° 712 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Végétation [Termes IGN] approximation [Termes IGN] Picea abies [Termes IGN] tomographie [Termes IGN] ultrason Résumé : (auteur) Ultrasonic computed tomography in reflection was used to assess the integrity of green wood. Qualitative reflectivity images were obtained from back-scattered measurements by reflection tomography, like ultrasound in medical applications. The reconstruction algorithm was designed using, in particular, a linear approximation of the forward problem (Born approximation) and based on the assumption that a transversal cross section of wood is isotropic. The experimental device was composed of only one rotating emitter–receiver transducer to record and compute the projections. In this specific case, a tomographic projection was directly associated with a recorded signal. The qualitative aspect of this imaging technique was validated by performing a numerical simulation and tested on a small diameter green wood (Picea abies) log. The images obtained were geometrically accurate considering the internal inclusions. It was, however, not possible in the simulation to differentiate the object shape from the background (coupling medium) because the reflectivity value associated with the object was too low. The image obtained with the spruce sample mainly showed the position of the bark as indicated by a very high contrast area. The proportion of transmitted energy was, however, sufficient to reconstruct the artificial inclusion within the sample. Numéro de notice : A2008-693 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.1051/forest:200851 Date de publication en ligne : 20/09/2008 En ligne : https://doi.org/10.1051/forest:200851 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=71444 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
IFN-DIR-P000234	PER	Revue	Nogent-sur-Vernisson	Salle périodiques	Exclu du prêt