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Adapter les itinéraires sylvicoles pour atténuer les effets du changement climatique. Résultats pour la chênaie sessiliflore française à partir des réseaux d’expérimentations sylvicoles / François Lebourgeois in Revue forestière française, vol 69 n° 1 (octobre 2017)
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Titre : Adapter les itinéraires sylvicoles pour atténuer les effets du changement climatique. Résultats pour la chênaie sessiliflore française à partir des réseaux d’expérimentations sylvicoles Type de document : Article/Communication Auteurs : François Lebourgeois, Auteur ; Raphaël Trouvé, Auteur ; Jean-Daniel Bontemps , Auteur ; Catherine Collet, Auteur ; Sébastien Daviller, Auteur ; Fabien Spicher, Auteur ; François Ningre, Auteur ; Daniel Rittié, Auteur ; Claudine Richter, Auteur ; Ingrid Seynave, Auteur Année de publication : 2017 Projets : ARBRE / AgroParisTech (2007 -) Article en page(s) : pp 11 - 32 Note générale : Bibliographie Langues : Français (fre) Descripteur : [Termes IGN] analyse diachronique
[Termes IGN] croissance des arbres
[Termes IGN] densité de la végétation
[Termes IGN] Quercus sessiliflora
[Termes IGN] sécheresse
[Termes IGN] surveillance forestière
[Termes IGN] variation de densité
[Termes IGN] variation saisonnière
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (Auteur) Les effets de la densité du peuplement et de la sécheresse estivale ont été analysés sur la croissance en diamètre et en hauteur du Chêne sessile (Quercus petraea) à l’échelle du peuplement et de l’arbre. Les données des inventaires dendrométriques issues de deux réseaux d’expérimentations sylvicoles ont été utilisées (réseaux LERFOB et GIS Coop, 9 sites, 31 placettes, 99 inventaires, âges de 10 à 120 ans). Ces réseaux étudient les effets de larges gradients de densité, depuis des arbres en croissance libre (relative density index, ou RDI, proche de 0) jusqu’à des situations de densité maximale avec des phénomènes d’autoéclaircie (RDI supérieur ou égal à 1). Les conditions climatiques varient de 660 à 850 mm par an pour un gradient thermique de 9,5 à 11,5 °C (moyenne 1990-2010). D’une façon générale, la densité module très fortement la croissance des arbres et du peuplement, la sécheresse jouant un rôle secondaire mais néanmoins significatif. Les arbres dominés participent peu à la croissance du peuplement et ceci est d’autant plus vrai que le peuplement est dense. La sécheresse réduit la croissance et ceci particulièrement pour les arbres non dominants. Ainsi densité et sécheresse ont le même effet, c’est-à-dire qu’elles accentuent les différences de croissance entre arbres quand les contraintes augmentent. En allouant davantage de ressources à leur croissance en diamètre par rapport à leur croissance en hauteur, les arbres dans les peuplements ouverts sont « trapus ». Au contraire, dans les peuplements denses, c’est la « course à la lumière » avec une croissance en hauteur accrue et ceci d’autant plus que l’arbre est dominé. Dans tous les cas, la sécheresse réduit davantage la croissance en hauteur que la croissance en diamètre. Enfin, après une sécheresse exceptionnelle (1976), la récupération des arbres a été la plus rapide sur les sites les plus secs (récupération après 2 ans) et elle fut très faible pour les arbres dominés dans les peuplements les plus denses (toujours pas de récupération après 7 ans). Ces résultats suggèrent une meilleure adaptation des chênes sessiles dans les conditions plus sèches. Numéro de notice : A2017-703 Affiliation des auteurs : LIF+Ext (2012-2019) Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueNat DOI : 10.4267/2042/62970 Date de publication en ligne : 19/10/2017 En ligne : https://doi.org/10.4267/2042/62970 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=88084
in Revue forestière française > vol 69 n° 1 (octobre 2017) . - pp 11 - 32[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]Understanding the temporal behavior of crops using Sentinel-1 and Sentinel-2-like data for agricultural applications / Amanda Veloso in Remote sensing of environment, vol 199 (15 September 2017)
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Titre : Understanding the temporal behavior of crops using Sentinel-1 and Sentinel-2-like data for agricultural applications Type de document : Article/Communication Auteurs : Amanda Veloso, Auteur ; Stéphane Mermoz, Auteur ; Alexandre Bouvet, Auteur ; Thuy Le Toan, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 415 - 426 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] blé (céréale)
[Termes IGN] cultures
[Termes IGN] Glycine max
[Termes IGN] image optique
[Termes IGN] image Sentinel-MSI
[Termes IGN] image Sentinel-SAR
[Termes IGN] maïs (céréale)
[Termes IGN] Normalized Difference Vegetation Index
[Termes IGN] surveillance agricole
[Termes IGN] tournesol
[Termes IGN] variation saisonnière
[Termes IGN] variation temporelleRésumé : (auteur) Crop monitoring information is essential for food security and to improve our understanding of the role of agriculture on climate change, among others. Remotely sensing optical and radar data can help to map crop types and to estimate biophysical parameters, especially with the availability of an unprecedented amount of free Sentinel data within the Copernicus programme. These datasets, whose continuity is guaranteed up to decades, offer a unique opportunity to monitor crops systematically every 5 to 10 days. Before developing operational monitoring methods, it is important to understand the temporal variations of the remote sensing signal of different crop types in a given region. In this study, we analyse the temporal trajectory of remote sensing data for a variety of winter and summer crops that are widely cultivated in the world (wheat, rapeseed, maize, soybean and sunflower). The test region is in southwest France, where Sentinel-1 data have been acquired since 2014. Because Sentinel-2 data were not available for this study, optical satellites similar to Sentinel-2 are used, mainly to derive NDVI, for a comparison between the temporal behaviors with radar data. The SAR backscatter and NDVI temporal profiles of fields with varied management practices and environmental conditions are interpreted physically. Key findings from this analysis, leading to possible applications of Sentinel-1 data, with or without the conjunction of Sentinel-2, are then described. This study points out the interest of SAR data and particularly the VH/VV ratio, which is poorly documented in previous studies. Numéro de notice : A2017-418 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2017.07.015 En ligne : https://doi.org/10.1016/j.rse.2017.07.015 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86311
in Remote sensing of environment > vol 199 (15 September 2017) . - pp 415 - 426[article]Crown bulk density and fuel moisture dynamics in Pinus pinaster stands are neither modified by thinning nor captured by the Forest Fire Weather Index / Marc Soler Martin in Annals of Forest Science, vol 74 n° 3 (September 2017)
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Titre : Crown bulk density and fuel moisture dynamics in Pinus pinaster stands are neither modified by thinning nor captured by the Forest Fire Weather Index Type de document : Article/Communication Auteurs : Marc Soler Martin, Auteur ; José Antonio Bonet, Auteur ; Juan Martínez De Aragón, Auteur ; et al., Auteur Année de publication : 2017 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] biomasse (combustible)
[Termes IGN] éclaircie (sylviculture)
[Termes IGN] Espagne
[Termes IGN] forêt méditerranéenne
[Termes IGN] houppier
[Termes IGN] incendie de forêt
[Termes IGN] indice d'humidité
[Termes IGN] Pinus pinaster
[Termes IGN] risque naturel
[Termes IGN] surveillance forestière
[Termes IGN] traitement d'image
[Termes IGN] variation saisonnière
[Vedettes matières IGN] Ecologie forestièreRésumé : (Auteur)
Key message : No temporal change was recorded during summer in fuel availability in Pinus pinaster stands, contrary to predictions from the Forest Fire Weather Index. Also, thinning had no mid-term effect on fuel moisture or canopy structure.
Context : Forest fires are a major problem in Mediterranean countries. Management actions, such as fuel reductions, are one of the main tools to diminish fire risk, but the midterm efficacy of such tools remains largely untested with empirical data.
Aims : Here, we test for midterm effects of thinning on fuel moisture and crown bulk density in P. pinaster stands and whether temporal variations in fuel moisture correlated with predictions from the Fire Weather Index, a commonly used index on fire risk, and its components.
Methods : We compared fuel moisture over a fire season and crown bulk density in nine pairs of thinned/unthinned plots 7 years after treatments were applied.
Results : We observed that fuel moisture remained stable during a fire season, as a likely result of drought-induced physiological adjustments, including stomatal regulation and others, which allow leaves to maintain a large humidity even during drought, and that thinning had no midterm effect on fuel moisture or crown bulk density. Moreover, the Fire Weather Index and its components displayed different temporal dynamics than those observed in fuel moisture.
Conclusion : These results are important as they indicate that thinning may only have a limited, short-term impact towards diminishing the potential for crown fire spread in these stands and that current indices to evaluate fire risk may require a re-evaluation.Numéro de notice : A2017-354 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1007/s13595-017-0650-1 Date de publication en ligne : 28/06/2017 En ligne : http://doi.org/10.1007/s13595-017-0650-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85720
in Annals of Forest Science > vol 74 n° 3 (September 2017)[article]Quantifying the sources of epistemic uncertainty in model predictions of insect disturbances in an uncertain climate / David R. Gray in Annals of Forest Science, vol 74 n° 3 (September 2017)
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Titre : Quantifying the sources of epistemic uncertainty in model predictions of insect disturbances in an uncertain climate Type de document : Article/Communication Auteurs : David R. Gray, Auteur Année de publication : 2017 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] insecte nuisible
[Termes IGN] modèle conceptuel de données
[Termes IGN] modèle d'incertitude
[Termes IGN] prédiction
[Termes IGN] variation saisonnière
[Vedettes matières IGN] Ecologie forestièreRésumé : (Auteur) Key message : Natural disturbance can disrupt the anticipated delivery of forest-related ecosystem goods and services. Model predictions of natural disturbances have substantial uncertainties arising from the choices of input data and spatial scale used in the model building process, and the uncertainty of future climate conditions which are a major driver of disturbances. Quantifying the multiple contributions to uncertainty will aid decision making and guide future research needs.
Context : Forest management planning has been able, in the past, to rely on substantial empirical evidence regarding tree growth, succession, frequency and impacts of natural disturbances to estimate the future delivery of goods and services. Uncertainty has not been thought large enough to warrant consideration. Our rapidly changing climate is casting that empirical knowledge in doubt.
Aims : This paper describes how models of future spruce budworm outbreaks are plagued by uncertainty contributed by (among others): selection of data used in the model building process; model error; and uncertainty of the future climate and forest that will drive the future insect outbreak. The contribution of each to the total uncertainty will be quantified.
Methods : Outbreak models are built by the multivariate technique of reduced rank regression using different datasets. Each model and an estimate of its error are then used to predict future outbreaks under different future conditions of climate and forest composition. Variation in predictions is calculated, and the variance is apportioned among the model components that contributed to the epistemic uncertainty in predictions.
Results : Projections of future outbreaks are highly uncertain under the range of input data and future conditions examined. Uncertainty is not uniformly distributed spatially; the average 75% confidence interval for outbreak duration is 10 years. Estimates of forest inventory for model building and choice of climate scenario for projections of future climate had the greatest contributions to predictions of outbreak duration and severity.
Conclusion : Predictions of future spruce budworm outbreaks are highly uncertain. More precise outbreak data with which to build a new outbreak model will have the biggest impact on reducing uncertainty. However, an uncertain future climate will continue to produce uncertainty in outbreak projections. Forest management strategies must, therefore, include alternatives that present a reasonable likelihood of achieving acceptable outcomes over a wide range of future conditions.Numéro de notice : A2017-356 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1007/s13595-017-0645-y Date de publication en ligne : 21/06/2017 En ligne : https://doi.org/10.1007/s13595-017-0645-y Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85723
in Annals of Forest Science > vol 74 n° 3 (September 2017)[article]Reconstruction of time-varying tidal flat topography using optical remote sensing imageries / Kuo-Hsin Tseng in ISPRS Journal of photogrammetry and remote sensing, vol 131 (September 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)PermalinkEffects of urban tree canopy loss on land surface temperature magnitude and timing / Arthur Elmes in ISPRS Journal of photogrammetry and remote sensing, vol 128 (June 2017)PermalinkOn the short-term temporal variations of GNSS receiver differential phase biases / Baocheng Zhang in Journal of geodesy, vol 91 n° 5 (May 2017)PermalinkL’expansion séculaire des forêts françaises est dominée par l’accroissement du stock sur pied et ne sature pas dans le temps / Anaïs Denardou-Tisserand in Revue forestière française, vol 69 n° 4-5 (2017)PermalinkSpatial–temporal variations of water vapor content over Ethiopia: a study using GPS observations and the ECMWF model / Kibrom Ebuy Abraha in GPS solutions, vol 21 n° 1 (January 2017)PermalinkA global study of NDVI difference among moderate-resolution satellite sensors / Xingwang Fan in ISPRS Journal of photogrammetry and remote sensing, vol 121 (November 2016)PermalinkA new climatology of maximum and minimum temperature (1951–2010) in the Spanish mainland: a comparison between three different interpolation methods / D. Peña-Angulo in International journal of geographical information science IJGIS, vol 30 n° 11-12 (November - December 2016)PermalinkDirect measurement of evapotranspiration from a forest using a superconducting gravimeter / Michel Van Camp in Geophysical research letters, vol 43 n° 19 (15 October 2016)PermalinkLong-term soil moisture dynamics derived from GNSS interferometric reflectometry: a case study for Sutherland, South Africa / Sibylle Vey in GPS solutions, vol 20 n° 4 (October 2016)Permalink