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Mapping and quantification of the dwarf eelgrass Zostera noltii using a random forest algorithm on a SPOT 7 satellite image / Salma Benmokhtar in ISPRS International journal of geo-information, vol 10 n° 5 (May 2021)
[article]
Titre : Mapping and quantification of the dwarf eelgrass Zostera noltii using a random forest algorithm on a SPOT 7 satellite image Type de document : Article/Communication Auteurs : Salma Benmokhtar, Auteur ; Marc Robin, Auteur ; Mohamed Maanan, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 313 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] apprentissage automatique
[Termes IGN] biomasse
[Termes IGN] cartographie hydrographique
[Termes IGN] classification par forêts d'arbres décisionnels
[Termes IGN] fond marin
[Termes IGN] herbier marin
[Termes IGN] image SPOT 7
[Termes IGN] Maroc
[Termes IGN] Normalized Difference Vegetation Index
[Termes IGN] plante aquatique d'eau salée
[Termes IGN] réflectance spectrale
[Termes IGN] typologie
[Termes IGN] Zostera noltiiRésumé : (auteur) The dwarf eelgrass Zostera noltei Hornemann (Z. noltei) is the most dominant seagrass in semi-enclosed coastal systems of the Atlantic coast of Morocco. The species is experiencing a worldwide decline and monitoring the extent of its meadows would be a useful approach to estimate the impacts of natural and anthropogenic stressors. Here, we aimed to map the Z. noltei meadows in the Merja Zerga coastal lagoon (Atlantic coast of Morocco) using remote sensing. We used a random forest algorithm combined with field data to classify a SPOT 7 satellite image. Despite the difficulties related to the non-synchronization of the satellite images with the high tide coefficient, our results revealed, with an accuracy of 95%, that dwarf eelgrass beds can be discriminated successfully from other habitats in the lagoon. The estimated area was 160.76 ha when considering mixed beds (Z. noltei-associated macroalgae). The use of SPOT 7 satellite images seems to be satisfactory for long-term monitoring of Z. noltei meadows in the Merja Zerga lagoon and for biomass estimation using an NDVI–biomass quantitative relationship. Nevertheless, using this method of biomass estimation for dwarf eelgrass meadows could be unsuccessful when it comes to areas where the NDVI is saturated due to the stacking of many layers. Numéro de notice : A2021-393 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/ijgi10050313 Date de publication en ligne : 07/05/2021 En ligne : https://doi.org/10.3390/ijgi10050313 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97679
in ISPRS International journal of geo-information > vol 10 n° 5 (May 2021) . - n° 313[article]Self-thinning tree mortality models that account for vertical stand structure, species mixing and climate / David I. Forrester in Forest ecology and management, Vol 487 ([01/05/2021])
[article]
Titre : Self-thinning tree mortality models that account for vertical stand structure, species mixing and climate Type de document : Article/Communication Auteurs : David I. Forrester, Auteur ; Thomas G. Backer, Auteur ; Stephen R. Elms, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 118936 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Abies alba
[Termes IGN] Australie
[Termes IGN] auto-éclaircie
[Termes IGN] changement climatique
[Termes IGN] Chine
[Termes IGN] dépérissement
[Termes IGN] Eucalyptus nitens
[Termes IGN] Fagus sylvatica
[Termes IGN] modèle de croissance végétale
[Termes IGN] mortalité
[Termes IGN] peuplement forestier
[Termes IGN] peuplement mélangé
[Termes IGN] Picea abies
[Termes IGN] Pinus sylvestris
[Termes IGN] Quercus pedunculata
[Termes IGN] Quercus sessiliflora
[Termes IGN] structure de la végétation
[Termes IGN] Suisse
[Vedettes matières IGN] SylvicultureRésumé : (auteur) Self-thinning dynamics are often considered when managing stand density in forests and are used to constrain forest growth models. However, self-thinning relationships are often quantified using only data at a conceptualised self-thinning line, even though self-thinning can begin before the stand actually reaches a self-thinning line. Also, few self-thinning relationships account for the effects of species composition in mixed-species forests, and stand structure such as relative height of species (in mixtures), and/or size or age cohorts in uneven-aged forests. Such considerations may be important given the effects of global climate change and interest in mixed-species and uneven-aged forests. The objective of this study was to develop self-thinning relationships based on changes in the tree density relative to mean tree diameter, instead of focusing only on data for state variables (e.g. tree density) at the self-thinning line. This was done while also considering how the change in tree density is influenced by site quality and stand structure (species composition and relative height). The relationships were modelled using data from temperate Australian Eucalyptus plantations (436 plots), subtropical forests in China (88 plots), and temperate forests in Switzerland (1055 plots). Zero-inflated and hurdle generalized linear models with Poisson and negative binomial distributions were fit for several species, as well as for all-species equations. The intercepts and slopes of the self-thinning lines were higher than many published studies which may have resulted from both the less restrictive equation form and data selection. The rates of self-thinning often decreased as the proportion of the object species increased, as relative height increased (species or size cohort became more dominant), and as site (quality) index increased. The effects of aridity varied between species, with self-thinning increasing with aridity index for Abies alba, Pinus sylvestris, Quercus petraea and Quercus robur, but decreasing with aridity index for Eucalyptus nitens, Fagus sylvatica and Picea abies as sites became wetter and cooler. Self-thinning model parameters were not correlated with species traits, including specific leaf area, wood basic density or crown diameter – stem diameter allometry. All-species self-thinning relationships based on all data could be adjusted using a correction factor for rarer species where there were insufficient data to develop species-specific equations. The approach and equations developed could be used in forest growth models to calculate how the tree density declines as mean tree size increases, as height changes relative to other cohorts or species, as species proportions change, and as climatic and edaphic conditions change. Numéro de notice : A2021-355 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1016/j.foreco.2021.118936 Date de publication en ligne : 18/02/2021 En ligne : https://doi.org/10.1016/j.foreco.2021.118936 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97612
in Forest ecology and management > Vol 487 [01/05/2021] . - n° 118936[article]Towards silviculture guidelines to produce large-sized silver birch (betula pendula roth) logs in Western Europe / Héloïse Dubois in Forests, vol 12 n° 5 (May 2021)
[article]
Titre : Towards silviculture guidelines to produce large-sized silver birch (betula pendula roth) logs in Western Europe Type de document : Article/Communication Auteurs : Héloïse Dubois, Auteur ; Hugues Claessens, Auteur ; Gauthier Ligot, Auteur Année de publication : 2021 Article en page(s) : n° 599 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Betula pendula
[Termes IGN] croissance des arbres
[Termes IGN] densité du bois
[Termes IGN] diamètre à hauteur de poitrine
[Termes IGN] Hauts-de-France (région 2016)
[Termes IGN] houppier
[Termes IGN] tronc
[Termes IGN] Wallonie (Belgique)
[Vedettes matières IGN] ForesterieRésumé : (auteur) Forest health problems arising from climate change, pests and pathogens are a threat to the main timber tree species. As a result, silver birch (Betula pendula Roth) has become a precious asset for meeting oncoming forestry challenges in western Europe. However, silviculture guidelines to produce high-value birch logs in this region are lacking. Producing large-sized birch trunks requires crown release, i.e., removing crown competitors around selected target trees. These interventions are currently seldom carried out or else too late when the growth potential of the trees has already diminished. This study set out to ascertain the diameter at breast height (dbh) that could be reached by crown-released birch, determine dbh-associated crown diameters, and further characterize the gain obtained from early crown release on birch dbh growth. We measured 704 birch trees that had undergone crown release in 38 naturally regenerated pure birch stands in southern Belgium and in northeastern France. We then evaluated the variation in stem and crown diameter, and analyzed increments in response to the earliness of the interventions in three subsamples, also compared with control target birch. We found that trees with a dbh of 50 cm could be grown within 60 years. Based on crown diameter, to produce 40, 50 and 60 cm dbh trunk, the distance required between target birch trees at the end of the rotation was around 8, 10 and 12 m. With no intervention and in ordinary dense birch regenerations, the dbh increment was found to decline once the stand reached age 4–7 years. Starting crown release in stands aged 4–5 years can double the dbh increment of target trees and provide a continual gain that may last up to 20 years. When birch crowns are released after 9–12 years, it may already be too late for them to recover their best growth rate. Our contribution should help complete emerging guidelines in support of birch silviculture development. Numéro de notice : A2021-401 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.3390/f12050599 Date de publication en ligne : 11/05/2021 En ligne : https://doi.org/10.3390/f12050599 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97703
in Forests > vol 12 n° 5 (May 2021) . - n° 599[article]The delineation of tea gardens from high resolution digital orthoimages using mean-shift and supervised machine learning methods / Akhtar Jamil in Geocarto international, vol 36 n° 7 ([15/04/2021])
[article]
Titre : The delineation of tea gardens from high resolution digital orthoimages using mean-shift and supervised machine learning methods Type de document : Article/Communication Auteurs : Akhtar Jamil, Auteur ; Bulent Bayram, Auteur Année de publication : 2021 Article en page(s) : pp 758 - 772 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] algorithme de décalage moyen
[Termes IGN] analyse d'image orientée objet
[Termes IGN] apprentissage automatique
[Termes IGN] arbre de décision
[Termes IGN] Camellia sinensis
[Termes IGN] classification dirigée
[Termes IGN] classification par forêts d'arbres décisionnels
[Termes IGN] classification par réseau neuronal
[Termes IGN] classification par séparateurs à vaste marge
[Termes IGN] exploitation agricole
[Termes IGN] extraction de la végétation
[Termes IGN] Normalized Difference Vegetation Index
[Termes IGN] orthoimage
[Termes IGN] segmentation hiérarchique
[Termes IGN] TurquieRésumé : (Auteur) Rize district is an important tea production site in Turkey, which is known for high quality tea. Determining the temporal changes is very crucial from the viewpoint of agricultural management and protection of tea areas. In addition, delineation of tea gardens using photogrammetric evaluation techniques for a single orthoimage takes approximately 8 h of labour work, which is both costly and time-consuming process. To overcome these issues, a method is proposed for demarcation of tea gardens from high-resolution orthoimages. In this article, a hierarchical object-based segmentation using mean-shift (MS) and supervised machine learning (ML) methods are investigated for delineation of tea gardens. First, the MS algorithm was applied to partition the images into homogeneous segments (objects) and then from each segment, various spectral, spatial and textural features were extracted. Finally, four most widely used supervised ML classifiers, support vector machine (SVM), artificial neural network (ANN), random forest (RF), and decision trees (DTs), were selected for classification of objects into tea gardens and other types of trees. Photogrammetrically evaluated tea garden borders were taken as reference data to evaluate the performance of the proposed methods. The experiments showed that all selected supervised classifiers were effective for delineation of the tea gardens from high-resolution images. Numéro de notice : A2021-293 Affiliation des auteurs : non IGN Thématique : IMAGERIE/INFORMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106049.2019.1622597 Date de publication en ligne : 19/06/2019 En ligne : https://doi.org/10.1080/10106049.2019.1622597 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97349
in Geocarto international > vol 36 n° 7 [15/04/2021] . - pp 758 - 772[article]Chemical interaction between Quercus pubescens and its companion species is not emphasized under drought stress / H. Hashoum in European Journal of Forest Research, vol 140 n° 2 (April 2021)
[article]
Titre : Chemical interaction between Quercus pubescens and its companion species is not emphasized under drought stress Type de document : Article/Communication Auteurs : H. Hashoum, Auteur ; J. Gavinet, Auteur ; T. Gauquelin, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : pp 333 - 343 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] biochimie
[Termes IGN] Cotinus coggygria
[Termes IGN] croissance des arbres
[Termes IGN] dynamique de la végétation
[Termes IGN] phytobiologie
[Termes IGN] Pinus halepensis
[Termes IGN] Quercus pubescens
[Termes IGN] régénération (sylviculture)
[Termes IGN] sécheresse
[Termes IGN] stress hydrique
[Vedettes matières IGN] ForesterieRésumé : (auteur) How plant–plant interactions will interact with global change drivers such as increased drought during the regeneration phase is a key question to forecast future vegetation dynamics. Chemical interaction and especially allelopathy and drought have been suggested to affect plant performance synergistically, i.e., that plant under drought stress would be more sensitive to allelochemicals and that exposure to allelopathic interactions could increase drought sensitivity through an inhibition of root development and mycorrhization. In this paper, we tested these hypotheses by using a controlled experiment with Quercus pubescens Mill. as a target species and three co-occurring species plus itself as source species. Allelopathic treatments consisted of annual provision of litter and monthly watering with green leaf aqueous extracts during two vegetation seasons starting from oak acorns. During the second vegetation season, a drought stress treatment was added on half of the seedlings. Allelopathy of co-occurring species reduced seedlings dimensions while Q. pubescens treatment increased it. During the second vegetation season, seedling growth rate and physiology were reduced by drought but poorly affected by allelopathic treatment. At the end of the experiment, drought stress and allelopathy from Cotinus coggygria and Pinus halepensis both reduced seedling biomass but had opposite effects on the root/shoot ratio. Drought and allelopathy did not interact significantly and, contrary to our hypothesis, there was a tendency of lower allelopathic effects under drought. Our results suggest that drought and allelopathy could additively alter seedling development, but the opposite effects of allelopathy and drought on the root/shoot ratio call for further experiments testing the interaction between these two factors. Numéro de notice : A2021-399 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1007/s10342-020-01337-w Date de publication en ligne : 25/11/2020 En ligne : https://doi.org/10.1007/s10342-020-01337-w Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97699
in European Journal of Forest Research > vol 140 n° 2 (April 2021) . - pp 333 - 343[article]A CNN approach to simultaneously count plants and detect plantation-rows from UAV imagery / Lucas Prado Osco in ISPRS Journal of photogrammetry and remote sensing, vol 174 (April 2021)PermalinkFour-year-performance of oak and pine seedlings following mechanical site preparation with lightweight excavators / Noé Dumas in Silva fennica, vol 55 n° 2 (April 2021)PermalinkStreams and rural abandonment are related to the summer activity of the invasive pest Drosophila suzukii in protected European forests / Alberto Maceda-Veiga in Forest ecology and management, vol 485 ([01/04/2021])PermalinkTree extraction and estimation of walnut structure parameters using airborne LiDAR data / Javier Estornell in International journal of applied Earth observation and geoinformation, vol 96 (April 2021)PermalinkApplication of thermal imaging and hyperspectral remote sensing for crop water deficit stress monitoring / Gopal Krishna in Geocarto international, vol 36 n° 5 ([15/03/2021])PermalinkAre pine-oak mixed stands in Mediterranean mountains more resilient to drought than their monospecific counterparts? / Francisco J. Muñoz-Gálvez in Forest ecology and management, vol 484 ([15/03/2021])PermalinkTerrestrial laser scanning intensity captures diurnal variation in leaf water potential / S. Junttila in Remote sensing of environment, Vol 255 (March 2021)PermalinkAnalysis of plot-level volume increment models developed from machine learning methods applied to an uneven-aged mixed forest / Seyedeh Kosar Hamidi in Annals of Forest Science, vol 78 n° 1 (March 2021)PermalinkEuropean beech leads to more bioactive humus forms but stronger mineral soil acidification as Norway spruce and Scots pine – Results of a repeated site assessment after 63 and 82 years of forest conversion in Central Germany / Florian Achilles in Forest ecology and management, vol 483 ([01/03/2021])PermalinkIs the seasonal variation in frost resistance and plant performance in four oak species affected by changing temperatures? / Maggie Preißer in Forests, vol 12 n° 3 (March 2021)Permalink