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Strong gradients in forest sensitivity to climate change revealed by dynamics of forest fire cycles in the post Little Ice Age Era / Igor Drobyshev in Journal of geophysical research : Biogeosciences, vol 122 n° 10 (October 2017)
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Titre : Strong gradients in forest sensitivity to climate change revealed by dynamics of forest fire cycles in the post Little Ice Age Era Type de document : Article/Communication Auteurs : Igor Drobyshev, Auteur ; Yves Bergeron, Auteur ; Martin P. Girardin, Auteur ; Sylvie Gauthier, Auteur ; Clémentine Ols , Auteur ; John Ojal, Auteur
Année de publication : 2017 Projets : PREREAL / Ali, Ahmed Adam Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Amérique du nord
[Termes IGN] analyse diachronique
[Termes IGN] changement climatique
[Termes IGN] circulation atmosphérique
[Termes IGN] forêt boréale
[Termes IGN] forêt tempérée
[Termes IGN] incendie de forêt
[Termes IGN] Moyen-Age
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) The length of the fire cycle is a critical factor affecting the vegetation cover in boreal and temperate regions. However, its responses to climate change remain poorly understood. We reanalyzed data from earlier studies of forest age structures at the landscape level, in order to map the evolution of regional fire cycles across Eastern North American boreal and temperate forests, following the termination of the Little Ice Age (LIA). We demonstrated a well‐defined spatial pattern of post‐LIA changes in the length of fire cycles toward lower fire activity during the 1800s and 1900s. The western section of Eastern North America (west of 77°W) experienced a decline in fire activity as early as the first half of the 1800s. By contrast, the eastern section showed these declines as late as the early 1900s. During a regionally fire‐prone period of the 1910s–1920s, forests in the western section of Eastern boreal North America burned more than forests in the eastern section. The climate appeared to dominate over vegetation composition and human impacts in shaping the geographical pattern of the post‐LIA change in fire activity. Changes in the atmospheric circulation patterns following the termination of the LIA, specifically changes in Arctic Oscillation and the strengthening of the Continental Polar Trough, were likely drivers of the regional fire dynamics. Numéro de notice : A2017-912 Affiliation des auteurs : LIF+Ext (2012-2019) Autre URL associée : vers HAL Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1002/2017JG003826 Date de publication en ligne : 20/10/2017 En ligne : https://doi.org/10.1002/2017JG003826 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96696
in Journal of geophysical research : Biogeosciences > vol 122 n° 10 (October 2017)[article]Variance of light-related foliar traits across spatial and temporal scales in the Mediterranean evergreen Olea europaea L. / Adrián G. Escribano-Rocafort in Perspectives in Plant Ecology, Evolution and Systematics, vol 28 (October 2017)
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Titre : Variance of light-related foliar traits across spatial and temporal scales in the Mediterranean evergreen Olea europaea L. Type de document : Article/Communication Auteurs : Adrián G. Escribano-Rocafort, Auteur ; Agustina B. Ventre-Lespiaucq, Auteur ; Carlos Granado-Yela, Auteur ; et al., Auteur Année de publication : 2017 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique
[Termes IGN] climat méditerranéen
[Termes IGN] distribution spatiale
[Termes IGN] feuille (végétation)
[Termes IGN] houppier
[Termes IGN] Olea europaea
[Termes IGN] variance
[Termes IGN] variation saisonnièreRésumé : (auteur) The variability in space and time of a given set of traits can describe the biological activity of plants and influence species interactions and the properties of communities and ecosystems. However, seasonal variance in foliar traits of tree species has been poorly addressed in the Mediterranean climate despite its potential implications in fundamental processes such as light interception strategies.
Due to seasonal variation in the apparent sun path’s trajectory, predictable radiation patterns across crown positions may determine the variance partitioning for light-related leaf traits in evergreens. We hypothesize that in the most exposed part of the crown i.e. south, trait variance should be constrain due to abiotic stress compared to less exposed crown positions.
We partitioned the variance across five nested scales for a set of traits that capture leaf form, structure, position relative to the sun and the potential area exposed in a given time in Olea europaea L. trees. The scales included temporal variation due to sampling in two different seasons and twelve spatially structured crown positions within trees. We conducted multivariate analyses to assess the variability among traits, within trees and among trees
The variance partitioning at the season scale was low and the structure conserved between seasons for most traits. Intraindividual variance was conspicuous for all traits evidencing a spatial gradient of trait distribution within trees from outer to inner layers and among paired crown sectors (North-East, South-West). Leaf angles and potential exposure to direct light had an absence of variance at scales above crown positions.
The spatial distribution of crown sectors and layers had a distinct influence on the expression of leaf attributes among traits. Environmental filters may constrain variability on the outermost layer of the crown and on all crown positions during summer and winter, due to combination of the high irradiance and water stress in Mediterranean climates.Numéro de notice : A2017-390 Affiliation des auteurs : non IGN Thématique : FORET/GEOMATIQUE Nature : Article DOI : 10.1016/j.ppees.2017.07.003 En ligne : https://doi.org/10.1016/j.ppees.2017.07.003 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85889
in Perspectives in Plant Ecology, Evolution and Systematics > vol 28 (October 2017)[article]Wind loads and competition for light sculpt trees into self-similar structures / Christophe Eloy in Nature communications, vol 8 (2017)
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Titre : Wind loads and competition for light sculpt trees into self-similar structures Type de document : Article/Communication Auteurs : Christophe Eloy, Auteur ; Meriem Fournier, Auteur ; André Lacointe, Auteur ; Bruno Moulia, Auteur Année de publication : 2017 Langues : Anglais (eng) Descripteur : [Termes IGN] arbre (flore)
[Termes IGN] croissance des arbres
[Termes IGN] données allométriques
[Termes IGN] modèle numérique
[Termes IGN] rayonnement lumineux
[Termes IGN] structure de la végétation
[Termes IGN] vent
[Vedettes matières IGN] BotaniqueRésumé : (auteur) Trees are self-similar structures: their branch lengths and diameters vary allometrically within the tree architecture, with longer and thicker branches near the ground. These tree allometries are often attributed to optimisation of hydraulic sap transport and safety against elastic buckling. Here, we show that these allometries also emerge from a model that includes competition for light, wind biomechanics and no hydraulics. We have developed MECHATREE, a numerical model of trees growing and evolving on a virtual island. With this model, we identify the fittest growth strategy when trees compete for light and allocate their photosynthates to grow seeds, create new branches or reinforce existing ones in response to wind-induced loads. Strikingly, we find that selected trees species are self-similar and follow allometric scalings similar to those observed on dicots and conifers. This result suggests that resistance to wind and competition for light play an essential role in determining tree allometries. Numéro de notice : A2017-780 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1038/s41467-017-00995-6 En ligne : https://doi.org/10.1038/s41467-017-00995-6 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=88980
in Nature communications > vol 8 (2017)[article]Tree size thresholds produce biased estimates of forest biomass dynamics / Eric B. Searle in Forest ecology and management, vol 400 (15 September 2017)
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Titre : Tree size thresholds produce biased estimates of forest biomass dynamics Type de document : Article/Communication Auteurs : Eric B. Searle, Auteur ; Han Y.H. Chen, Auteur Année de publication : 2017 Article en page(s) : pp 468 - 474 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] biomasse aérienne
[Termes IGN] changement climatique
[Termes IGN] diamètre des arbres
[Termes IGN] échantillonnage
[Termes IGN] erreur systématique
[Termes IGN] estimation statistique
[Termes IGN] forêt boréale
[Termes IGN] inventaire forestier (techniques et méthodes)
[Termes IGN] inventaire forestier étranger (données)
[Termes IGN] Manitoba (Canada)
[Termes IGN] placette d'échantillonnage
[Termes IGN] seuillage
[Vedettes matières IGN] Inventaire forestierRésumé : (auteur) Studies that examine forest biomass dynamics often rely on long-term, spatially extensive, repeatedly measured permanent sample plots. Due to the intensive cost of sampling all trees within these plots, an arbitrary size threshold is typically imposed, which leads to only larger trees being sampled. However, it remains unclear whether the sampling of only large trees is representative of the entirety of stands of diverse sizes; the sampling of only large trees may produce biased estimates of biomass dynamics (growth, ingrowth, and mortality). Using a network of 141 permanent sample plots from Manitoba, Canada, with all trees of >1.3 m in height repeatedly measured, we constructed three distinct data sets, with 10 cm, 5 cm, and no diameter at breast height threshold, to illustrate that total productivity and mortality are increasingly underestimated with increasingly larger diameter at breast height thresholds. This effect is particularly significant in young stands, where productivity estimates peak at least 20 years earlier than the determined estimates under large thresholds. We highlight the need to account for smaller trees in long-term observational studies to ensure unbiased estimates of stand level aboveground biomass productivity and loss. Numéro de notice : A2017-807 Affiliation des auteurs : non IGN Thématique : FORET/MATHEMATIQUE Nature : Article DOI : 10.1016/j.foreco.2017.06.042 En ligne : https://doi.org/10.1016/j.foreco.2017.06.042 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89245
in Forest ecology and management > vol 400 (15 September 2017) . - pp 468 - 474[article]Assimilation de données géodésiques et estimation de références pour l’étude du changement climatique – Présentation du projet ANR GEODESIE / David Coulot in XYZ, n° 152 (septembre - novembre 2017)
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Titre : Assimilation de données géodésiques et estimation de références pour l’étude du changement climatique – Présentation du projet ANR GEODESIE Type de document : Article/Communication Auteurs : David Coulot , Auteur ; et al., Auteur
Année de publication : 2017 Projets : GEODESIE / Coulot, David Article en page(s) : pp 39 - 46 Note générale : bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] altimétrie satellitaire par radar
[Termes IGN] assimilation des données
[Termes IGN] changement climatique
[Termes IGN] données géodésiques
[Termes IGN] International Terrestrial Reference Frame
[Termes IGN] niveau moyen des mers
[Termes IGN] série temporelleRésumé : (auteur) Le projet GEODESIE vise à déterminer des références géodésiques globales, cohérentes et de grandes exactitude (série temporelles de repères terrestres et célestes, de paramètres d'orientation de la terre et d'orbites de satellites d'observation de la Terre) par un retraitement optimal de l'ensemble des données de géodésie spatiales disponibles depuis le début des années 1980. Ces références seront mises à disposition des communautés de recherche géophysiques et climatiques pour de meilleures estimations de la montée du niveau des mers, de la fonte des glaces récente et du changement climatique global. Des séries temporelles de niveaux des mers géocentriques, calculées avec les données des altimètres satellitaires et les enregistrements des marégraphes, sur la base de ces références, seront également fournies après la fin du projet. Numéro de notice : A2017-591 Affiliation des auteurs : LASTIG LAREG (2012-mi2018) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtSansCL DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86756
in XYZ > n° 152 (septembre - novembre 2017) . - pp 39 - 46[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 112-2017031 RAB Revue Centre de documentation En réserve L003 Disponible Documents numériques
en open access
Assimilation de données géodésiques - pdf éditeurAdobe Acrobat PDFLa combinaison de l'image satellitaire avec les données citoyennes pour la mesure de l'ïlot de chaleur urbain : Premiers résultats sur la métropole de Lyon / Florent Renard in Ingénierie des systèmes d'information, ISI : Revue des sciences et technologies de l'information, RSTI, vol 22 n° 5 (septembre - octobre 2017)
PermalinkA derivation of the Vlasov–Navier–Stokes model for aerosol flows from kinetic theory / Etienne Bernard in Communications in Mathematical Sciences, vol 15 n° 6 ([01/09/2017])
PermalinkDetermination of the ionospheric foF2 using a stand-alone GPS receiver / Dudy D Wijaya in Journal of geodesy, vol 91 n° 9 (September 2017)
PermalinkEffects of using different sources of remote sensing and geographic information system data on urban stormwater 2D–1D modeling / Yi Hong in Applied sciences, vol 7 n° 9 (September 2017)
PermalinkGroup delay variations of GPS transmitting and receiving antennas / Lambert Wanninger in Journal of geodesy, vol 91 n° 9 (September 2017)
PermalinkImproving BeiDou real-time precise point positioning with numerical weather models / Cuixian Lu in Journal of geodesy, vol 91 n° 9 (September 2017)
PermalinkHERA: A dynamic web application for visualizing community exposure to flood hazards based on storm and sea level rise scenarios / Jeanne M. Jones in Computers & geosciences, vol 109 (December 2017)
PermalinkVisual analytics of time-varying multivariate ionospheric scintillation data / Aurea Soriano-Vargas in Computers and graphics, vol 68 (November 2017)
PermalinkApplication of ray-traced tropospheric slant delays to geodetic VLBI analysis / Armin Hofmeister in Journal of geodesy, vol 91 n° 8 (August 2017)
PermalinkEvaluation of seasonal variations of remotely sensed leaf area index over five evergreen coniferous forests / Rong Wang in ISPRS Journal of photogrammetry and remote sensing, vol 130 (August 2017)
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