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A comparison of two methods of data collection for modelling productivity of harvesters: manual time study and follow-up study using on-board-computer stem records / Julia Brewer in Annals of forest research, vol 61 n° 1 (January - June 2018)
[article]
Titre : A comparison of two methods of data collection for modelling productivity of harvesters: manual time study and follow-up study using on-board-computer stem records Type de document : Article/Communication Auteurs : Julia Brewer, Auteur ; Bruce Talbot, Auteur ; Helmer Belbo, Auteur ; et al., Auteur Année de publication : 2018 Article en page(s) : pp 109 - 124 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse comparative
[Termes IGN] coupe (sylviculture)
[Termes IGN] diamètre à hauteur de poitrine
[Termes IGN] modèle numérique
[Termes IGN] Pinus patula
[Termes IGN] productivité
[Termes IGN] récolte de bois
[Vedettes matières IGN] SylvicultureRésumé : (auteur) Productivity of a mechanized P. patula cut-to-length harvesting operation was estimated and modelled using two methods of data collection: manual time study and follow-up study using StanForD stem files. The objective of the study was to compare the productivity models derived using these two methods to test for equivalence. Manual time studies were completed on four different machines and their operators. Two Ponsse Bear harvesters fitted with H8 heads, and two Ponsse Beaver harvesters, fitted with H6 heads, were included. All machines were equipped with Ponsse Opti2 information system. All four operators had approximately 1 year of experience working with their respective machines. The four machines worked in separate four-tree-wide harvesting corridors, and they each harvested 200 trees. Individual tree diameter at breast height (DBH), and height measurements were made manually. Subsequently, data on the trees in each study were extracted from the StanForD stem reports from each of the harvesters. Cycle times in the stem reports were determined based on the difference between consecutive harvest timestamps. The two methods were compared in terms of their abilities to estimate equivalent measures for tree DBH, volume, and productivity. In all four cases, significant differences were found between the DBH and volume measures derived using the two methods. Subsequently, the volume measures from the manual methods were used as the basis for productivity calculations. Results of the productivity comparisons found no significant differences between the models developed from the two methods. These results suggest that equivalent productivity models can be developed in terms of time using either method, however volume discrepancies indicate a need to reconcile bark and volume functions with the high variability experienced in the country. Numéro de notice : A2019-559 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.15287/afr.2018.962 Date de publication en ligne : 13/04/2019 En ligne : https://doi.org/10.15287/afr.2018.962 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93343
in Annals of forest research > vol 61 n° 1 (January - June 2018) . - pp 109 - 124[article]Terrestrial laser scanning reveals differences in crown structure of Fagus sylvatica in mixed vs. pure European forests / Ignacio Barbeito in Forest ecology and management, vol 405 (1 December 2017)
[article]
Titre : Terrestrial laser scanning reveals differences in crown structure of Fagus sylvatica in mixed vs. pure European forests Type de document : Article/Communication Auteurs : Ignacio Barbeito, Auteur ; Mathieu Dassot , Auteur ; Dominik Bayer, Auteur ; Catherine Collet, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 381 - 390 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Végétation
[Termes IGN] Allemagne
[Termes IGN] allométrie
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] Espagne
[Termes IGN] Fagus sylvatica
[Termes IGN] forêt
[Termes IGN] France (administrative)
[Termes IGN] houppier
[Termes IGN] productivité
[Termes IGN] SuèdeRésumé : (Auteur) Competition with neighboring trees of different species can affect crown size and shape. However, whether intra-specific differences in crown characteristics in mixed stands compared to pure stands are dependent on site conditions remains poorly understood. We used terrestrial laser scanning (TLS) to examine the differences in Fagus sylvatica crown characteristics at four sites, each of which contained pure stands of F. sylvatica and their mixture with Pinus sylvestris. These sites covered the area where the mixture occurs in Europe from south to north, representing a gradient of F. sylvatica productivity, defined as the mean increment of annual volume growth in pure F. sylvatica stands. Despite the large range in productivity, F. sylvatica trees in mixtures had larger crowns regardless of site conditions, with a higher proportion of their crown volume in the lower canopy compared to trees in pure stands. Larger crown volumes were related to higher live crown ratios and greater crown expansion, depending on the site. The magnitude of the mixing effect was variable among the crown characteristics evaluated, but overall our findings provide evidence that for a given species combination and density, the effect of mixture increased in the two most productive sites. TLS-derived novel crown metrics revealed that the mixing effect was affected by productivity, which was not captured by traditionally measured crown variables. Numéro de notice : A2017-880 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.foreco.2017.09.043 Date de publication en ligne : 02/10/2017 En ligne : https://doi.org/10.1016/j.foreco.2017.09.043 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91159
in Forest ecology and management > vol 405 (1 December 2017) . - pp 381 - 390[article]Accuracy accelerated / John Stenmark in GEO: Geoconnexion international, vol 16 n° 6 (June2017)
[article]
Titre : Accuracy accelerated Type de document : Article/Communication Auteurs : John Stenmark, Auteur Année de publication : 2017 Article en page(s) : pp 26 - 29 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Nivellement
[Termes IGN] Danemark
[Termes IGN] mise à jour de base de données
[Termes IGN] mise à jour en continu
[Termes IGN] précision des données
[Termes IGN] productivitéRésumé : (éditeur) A pioneering new approach in Denmark is boosting productivity in maintaining precise vertical data. Numéro de notice : A2017-204 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85012
in GEO: Geoconnexion international > vol 16 n° 6 (June2017) . - pp 26 - 29[article]Determining forest degradation, ecosystem state and resilience using a standard stand stocking measurement diagram: theory into practice / Carlos Bahamondez in Forestry, an international journal of forest research, vol 89 n° 3 (July 2016)
[article]
Titre : Determining forest degradation, ecosystem state and resilience using a standard stand stocking measurement diagram: theory into practice Type de document : Article/Communication Auteurs : Carlos Bahamondez, Auteur ; Ian D. Thompson, Auteur Année de publication : 2016 Article en page(s) : pp 290 - 300 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Chili
[Termes IGN] dégradation de la flore
[Termes IGN] écosystème forestier
[Termes IGN] forêt de production
[Termes IGN] Nothofagus (genre)
[Termes IGN] productivité
[Vedettes matières IGN] Ecologie forestièreRésumé : (auteur) Forest degradation is a major issue for policy-makers that is exacerbated by no clear and globally accepted definition of the term. For forest managers, a loss of forest productive capacity is one form of forest degradation. We present a quantitative method to assess forest degradation from a productivity perspective. Our method uses a standard stocking chart and calculation methods based on standard forest inventory data, to derive a clear threshold value for stocking, below which a forest should be considered degraded. The method is illustrated using the example of a self-regenerating Nothofagus production forest type from Chile. For that forest type, we determined that harvesting trees to below a specific basal area relative to site type, resulted in a loss of resilience, an unpredictable shift in ecosystem state, and a degraded condition. Our method illustrates how over-harvesting can degrade the long-term productivity of a stand and forest resilience. Nevertheless, it is important to consider that forests can also be degraded from other perspectives, such as loss of biodiversity, carbon, or protective functions as a result of excessive disturbances. Ecosystem management requires that managers consider degradation from a range of perspectives. We see the quantified approach used here as a way to provide practitioners with, in part, a transition from sustained yield to ecosystem management with an ultimate objective of providing a pathway towards adaptive management of complex systems and avoiding degradation. Numéro de notice : A2016--136 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1093/forestry/cpv052 Date de publication en ligne : 12/01/2016 En ligne : https://doi.org/10.1093/forestry/cpv052 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85779
in Forestry, an international journal of forest research > vol 89 n° 3 (July 2016) . - pp 290 - 300[article]La fabrication additive : une technologie de pointe économique et rapide / Anonyme in Informations entreprise, n° 160 supplément (mai 2016)
[article]
Titre : La fabrication additive : une technologie de pointe économique et rapide Type de document : Article/Communication Auteurs : Anonyme, Auteur Année de publication : 2016 Article en page(s) : pp 32 - 33 Langues : Français (fre) Descripteur : [Vedettes matières IGN] Techniques d'impression
[Termes IGN] impression 3D
[Termes IGN] productivité
[Termes IGN] secteur secondaire
[Termes IGN] technologieRésumé : (auteur) L'impression tridimensionnelle connaît une phase d’expansion sans précédent dans beaucoup de secteurs. Il est désormais possible de construire des pièces d'avion, des instruments de musique ou encore des vêtements grâce à cette technologie. Fort d'une expérience de 25 ans dans ce secteur, Materialise reste aujourd'hui une référence phare dans la fabrication additive. Une expertise et un savoir faire reconnus par les professionnels dans les 16 pays où la société est implantée. Numéro de notice : A2016-265 Affiliation des auteurs : non IGN Nature : Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80799
in Informations entreprise > n° 160 supplément (mai 2016) . - pp 32 - 33[article]Réservation
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