Descripteur
Documents disponibles dans cette catégorie (1246)
![](./images/expand_all.gif)
![](./images/collapse_all.gif)
Etendre la recherche sur niveau(x) vers le bas
Mapping individual tree health using full-waveform airborne laser scans and imaging spectroscopy: A case study for a floodplain eucalypt forest / Iurii Shendryk in Remote sensing of environment, vol 187 (15 December 2016)
![]()
[article]
Titre : Mapping individual tree health using full-waveform airborne laser scans and imaging spectroscopy: A case study for a floodplain eucalypt forest Type de document : Article/Communication Auteurs : Iurii Shendryk, Auteur ; Mark Broich, Auteur ; Mirela G. Tulbure, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 202 - 217 Note générale : bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] Australie
[Termes IGN] classification orientée objet
[Termes IGN] classification par forêts d'arbres décisionnels
[Termes IGN] dépérissement
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] Eucalyptus (genre)
[Termes IGN] Eucalyptus camaldulensis
[Termes IGN] inondation
[Termes IGN] spectrométrieRésumé : (auteur) Declining forest health can affect crucial ecosystem functions, such as carbon storage in biomass and soils, the regulation of water regimes, the modulation of regional climate and conservation of biodiversity. Airborne laser scanning (ALS) and imaging spectroscopy (IS) are two potentially complementary remote sensing technologies capable of characterizing and monitoring regional forest health. However, the combined use of ALS and IS data to classify the health of individual trees has not yet been assessed. In this study we propose a new approach utilizing ALS and IS combined to characterize the health of individual trees. Firstly, we applied a recently developed bottom-up individual tree delineation algorithm across a structurally complex floodplain eucalypt forest that has experienced episodes of severe dieback over the past six decades. We further calculated ALS and IS indices for delineated tree crowns and used them as predictor variables in machine learning models. We trained and evaluated an object-oriented random forest classifier against field-measured tree crown dieback and transparency ratios, as indicators of eucalypt tree health and crown density, respectively. Our results showed that dieback levels of individual trees can be classified using ALS and IS with an overall accuracy of 81% and a kappa score of 0.66, while the classification of tree crown transparency levels had an overall accuracy of 70% and a kappa score of 0.5. Returned pulse width, intensity and density related ALS indices were the most important predictors in the tree health classification, as they accounted for > 40% of the variance in the data. At the forest level in terms of dieback, 81.5% of correctly delineated trees were classified as healthy, 12.3% as declining and 6.2% as dying or dead. Dieback occurred primarily in areas that were flooded Numéro de notice : A2016-767 Affiliation des auteurs : non IGN Thématique : BIODIVERSITE/FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2016.10.014 En ligne : http://dx.doi.org/10.1016/j.rse.2016.10.014 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82411
in Remote sensing of environment > vol 187 (15 December 2016) . - pp 202 - 217[article]The protective effect of forests against rockfalls across the French Alps: Influence of forest diversity / S. Dupire in Forest ecology and management, vol 382 (15 December 2016)
![]()
[article]
Titre : The protective effect of forests against rockfalls across the French Alps: Influence of forest diversity Type de document : Article/Communication Auteurs : S. Dupire, Auteur ; Franck Bourrier, Auteur ; Jean-Matthieu Monnet, Auteur ; S. Bigot, Auteur ; Laurent Borgniet, Auteur ; Frédéric Berger, Auteur ; Thomas Curt, Auteur Année de publication : 2016 Article en page(s) : pp 269 - 279 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Alpes (France)
[Termes IGN] biodiversité végétale
[Termes IGN] composition floristique
[Termes IGN] éboulement
[Termes IGN] forêt alpestre
[Termes IGN] gradient de pente
[Termes IGN] longueur
[Termes IGN] pente
[Termes IGN] risque naturel
[Termes IGN] service écosystémique
[Vedettes matières IGN] Ecologie forestièreRésumé : (auteur) The role of forests in the mitigation of natural hazards has been repeatedly demonstrated. The protective effect of mountain forests against rockfalls has especially been pointed out because it can constitute a natural and cost-effective protection measure in many situations. However, this particular ecosystem service may substantially differ according to the structure and the composition of the forest. Until now, the rockfall protection capability has always been studied at a local scale with only few forest types. Moreover, the comparison of the protective effect of the different forest types studied remains difficult because different methods and indicators were used. For the same reasons, it is not possible to draw conclusions about the influence of biological and structural diversities on the protection capabilities of forests from former works.
The aims of this study were (1) to quantitatively assess the protective effect of forests at the French Alps scale and build a classification based on the protection capability, (2) to compare the protective effect of the different forest types present in the French Alps and (3) to analyze the relations between the protective effect and the forest diversity in terms of stand structure and tree composition. For this purpose, the model Rockyfor3D was used to simulate the propagation of rocks on 3886 different forest plots spread over the whole French Alps. Quantitative indicators characterizing the protective effect of each forest plot were then calculated from the simulation results and used to perform the different analyses.
Our results emphasized the importance of taking into account the length of forest in the maximum slope direction for an accurate assessment of the protective effect. Thus, the minimum length of forest to get a reduction of 99% of the rockfall hazard was chosen as indicator to compare protective effect between forests. Using this indicator, half of the French Alpine forests presented a high level of protection after a short forested slope (190 m). A decreasing gradient in the protection capabilities was observed from forest types dominated by broadleaved species to those dominated by conifer species. Moreover, considering an equivalent proportion of conifers, stands dominated by shade-tolerant tree species showed better ability to reduce rockfall hazard. Finally, our study highlighted that a high biodiversity and a structural heterogeneity within the forest have a positive effect on the reduction of rockfalls hazard.Numéro de notice : A2016-766 Affiliation des auteurs : non IGN Thématique : BIODIVERSITE/FORET Nature : Article DOI : 10.1016/j.foreco.2016.10.020 En ligne : http://dx.doi.org/10.1016/j.foreco.2016.10.020 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82405
in Forest ecology and management > vol 382 (15 December 2016) . - pp 269 - 279[article]Annual volume increment of the European forests—description and evaluation of the national methods used / Stein Michael Tomter in Annals of Forest Science, vol 73 n° 4 (December 2016)
![]()
[article]
Titre : Annual volume increment of the European forests—description and evaluation of the national methods used Type de document : Article/Communication Auteurs : Stein Michael Tomter, Auteur ; Andrius Kuliesis, Auteur ; Thomas Gschwantner, Auteur Année de publication : 2016 Article en page(s) : pp 849 - 856 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse comparative
[Termes IGN] arbre mort
[Termes IGN] Europe (géographie politique)
[Termes IGN] inventaire forestier (techniques et méthodes)
[Termes IGN] placette d'échantillonnage
[Termes IGN] Union Européenne
[Termes IGN] volume en bois
[Vedettes matières IGN] Inventaire forestierRésumé : (auteur) In order to obtain the necessary information for decision making etc., it is of increasing importance to be able to assess increment in a reliable way. Only repeated measurements on permanent sample plots in national forest inventories can provide accurate and comprehensive information on the various components of annual increment. Such inventory systems are increasingly employed in European countries. The felling/increment ratio, characterizing wood use sustainability, should be expressed as the ratio of felled living trees (excluding dead trees) and net increment.
Context : Reporting of gross and net annual increment is an element of international forest resource assessments and crucial for sustainable forest management. A number of approaches exist for the estimation of increment and its various sub-components.
Aims : The main objectives of the study are to assess in detail what methods European countries have used and are planning to use in the future for international reporting of increment. Also, the usefulness of the various approaches for the assessment of increment is evaluated.
Methods : A questionnaire asking about their assessment methods was distributed among the UNECE/FAO national correspondents of all European countries and members of the UNECE/FAO Team of Specialists on Monitoring Sustainable Forest Management. Databases of the Temperate and Boreal Forest Resource Assessment 2000 and of the State of Europe’s Forests 2011 were also used. Furthermore, the methodological background was described on the basis of relevant literature sources and some examples for country groups presented.
Results : Countries have indicated what methods they used for assessment of various increment components, and the percentage of countries, forest area, and growing stock corresponding to these replies has been calculated. With regard to gross annual increment, these metrics represent about one third for inventories based on permanent sample plots, but this percentage is on the increase.
Conclusion : The concept of the “control method” for forest management was developed more than 100 years ago but only utilized at the local level. The same methodology is now widely used at the national and regional level due to the implementation of modern national forest inventories using permanent sample plots. Care should be taken to utilize the data correctly for international forest resource assessments, in order to, e.g., avoid double counting of dead trees.Numéro de notice : A2016--163 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1007/s13595-016-055 Date de publication en ligne : 13/06/2016 En ligne : https://doi.org/10.1007/s13595-016-0557-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=87077
in Annals of Forest Science > vol 73 n° 4 (December 2016) . - pp 849 - 856[article]Cartographie de la dynamique de terroirs villageois à l’aide d’un drone dans les aires protégées de la République démocratique du Congo / Jean Semeki Ngabinzeke in Bois et forêts des tropiques, n° 330 (4e trimestre 2016)
![]()
[article]
Titre : Cartographie de la dynamique de terroirs villageois à l’aide d’un drone dans les aires protégées de la République démocratique du Congo Type de document : Article/Communication Auteurs : Jean Semeki Ngabinzeke, Auteur ; Julie Linchant, Auteur ; Samuel Quevauvillers, Auteur ; Jean-Marie Kahindo Muhongya, Auteur ; Philippe Lejeune, Auteur ; Cédric Vermeulen, Auteur Année de publication : 2016 Article en page(s) : pp 69 - 83 Note générale : bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] aire protégée
[Termes IGN] carte d'utilisation du sol
[Termes IGN] Congo
[Termes IGN] déboisement
[Termes IGN] défrichement
[Termes IGN] dégradation de l'environnement
[Termes IGN] détection de changement
[Termes IGN] drone
[Termes IGN] habitat (nature)
[Termes IGN] jachère
[Termes IGN] orthoimage
[Termes IGN] parc naturel national
[Termes IGN] utilisation du solRésumé : (auteur) Les aires protégées de la République démocratique du Congo (RDC) sont menacées par diverses pressions anthropiques nécessitant un suivi fréquent et précis. Le mini-drone Falcon équipé d’un appareil photo numérique Sony NEX-7 a été utilisé pour cartographier et suivre la dynamique d’un terroir villageois dans le Domaine de chasse de Mondo Missa à l’est du Parc national de la Garamba, au nord-est de la RDC. Un total de 3 143 photos acquises en avril et juillet 2015, avec une résolution au sol de 8 cm/pixel, a été orthorectifié. La cartographie a porté sur une zone de 114 ha. Les orthoimages ont d’abord été segmentées, les segments étant ensuite classés manuellement par photo-interprétation. Des changements notables ont été constatés entre les deux dates. Les zones des forêts et savanes ont perdu 6,5 ha (86,6 à 80,1 ha). Les jachères sont passées de 16,9 à 8,2 ha, les défriches de 4,1 à 10,0 ha. Les cultures saisonnières ont connu une variation allant de 3,2 à 11,8 ha. La taille moyenne des parcelles cultivées est de 0,2 ha (s = 0,14 ha ; n = 50). Enfin, la surface occupée par les arbres isolés a peu évolué (de 1,3 à 1,9 ha), celle des implantations humaines étant constante (1,7 ha). Ces résultats traduisent le fait que l’expansion de l’agriculture itinérante sur brûlis induit une conversion des habitats naturels et une modification de la composition végétale. Les aéronefs sans pilote à bord permettent de réaliser une cartographie précise et une surveillance rapide des changements d’affectation des terres à petite échelle dans les aires protégées des forêts et savanes tropicales. Ils offrent donc une solution efficace pour évaluer la déforestation et la dégradation au sein des espaces occupés par les communautés locales. Cette évaluation représente un enjeu important dans le processus REDD+ qui envisage de quantifier avec précision ces évolutions. Numéro de notice : A2016--114 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84768
in Bois et forêts des tropiques > n° 330 (4e trimestre 2016) . - pp 69 - 83[article]Documents numériques
en open access
Cartographie de la dynamique de terroirs villageoisAdobe Acrobat PDFComparing close-to-nature silviculture with processes in pristine forests: lessons from Central Europe / Jean-Philippe Schütz in Annals of Forest Science, vol 73 n° 4 (December 2016)
![]()
[article]
Titre : Comparing close-to-nature silviculture with processes in pristine forests: lessons from Central Europe Type de document : Article/Communication Auteurs : Jean-Philippe Schütz, Auteur ; Milan Saniga, Auteur ; Jurij Diaci, Auteur ; Tomas Vrska, Auteur Année de publication : 2016 Article en page(s) : pp 911 - 921 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Végétation
[Termes IGN] dynamique de la végétation
[Termes IGN] Europe centrale
[Termes IGN] sylvicultureRésumé : (auteur) [introduction] The term close-to-nature silviculture already contains some ambiguity since (silvi) culture implies the act of forest use. This notion was coined a long time ago by well-known silviculturists (Gayer 1885; Engler 1905; Leibundgut 1943 and more) to characterise a new form of forest management that differs from plantation forestry and the clear-cut system. The aim was a paradigmatic alternative to create multi-storeyed and rich mixed forest stands, with forest management emulating natural processes and seamless replacement of generations. Which of these processes should be selected and the degree to which natural forest dynamics should be imitated have not yet been specifically defined because the term was conceived in a general and conceptual sense and, furthermore, the aim has never been to let nature work alone. We can here quote Leibundgut (1943, p. 152) [transl. from German] “The main task of silviculture is to maximise and maintain the value produced by the forest”. Such a formulation is still quite relevant today, when the term “value” is understood in a broader sense. Actually, it would be more appropriate to use the term “utility” (original term “utilité”) in the sense of Biolley (1901). Numéro de notice : A2016--167 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1007/s13595-016-057 Date de publication en ligne : 12/09/2016 En ligne : https://doi.org/10.1007/s13595-016-0579-9 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=87204
in Annals of Forest Science > vol 73 n° 4 (December 2016) . - pp 911 - 921[article]vol 73 n° 4 - December 2016 - Forest Inventories at the European level (Bulletin de Annals of Forest Science) / Jean-Michel Leban
PermalinkGestion des peuplements en forêt publique : nouvelles pistes de recherche, développement et innovation / Christine Deleuze in Revue forestière française, vol 68 n° 6 (décembre 2016)
PermalinkOptimizing the bioindication of forest soil acidity, nitrogen and mineral nutrition using plant species / Paulina E. Pinto in Ecological indicators, vol 71 (December 2016)
PermalinkStatistical inference for forest structural diversity indices using airborne laser scanning data and the k-Nearest Neighbors technique / Matteo Mura in Remote sensing of environment, vol 186 (1 December 2016)
PermalinkThe role of European National Forest Inventories for international forestry reporting / Claude Vidal in Annals of Forest Science, vol 73 n° 4 (December 2016)
PermalinkTree diversity effect on dominant height in temperate forest / Patrick Vallet in Forest ecology and management, vol 381 (1 December 2016)
PermalinkEffective number of layers: A new measure for quantifying three-dimensional stand structure based on sampling with terrestrial LiDAR / Martin Ehbrecht in Forest ecology and management, vol 380 (15 november 2016)
PermalinkL'inventaire forestier à façon : une réponse à des besoins locaux de connaissance de la ressource / Fabienne Benest in Forêt entreprise, n° 231 (novembre décembre 2016)
PermalinkNatural regeneration of Pinus pinaster and Eucalyptus globulus from plantation into adjacent natural habitats / Patricia Fernandes in Forest ecology and management, vol 378 (15 October 2016)
PermalinkAboveground biomass mapping in French Guiana by combining remote sensing, forest inventories and environmental data / Ibrahim Fayad in International journal of applied Earth observation and geoinformation, vol 52 (October 2016)
Permalink