Descripteur
Documents disponibles dans cette catégorie (6)
Ajouter le résultat dans votre panier Affiner la recherche Interroger des sources externes
Etendre la recherche sur niveau(x) vers le bas
Radiative transfer modeling in structurally complex stands: towards a better understanding of parametrization / Frédéric André in Annals of Forest Science, vol 78 n° 4 (December 2021)
[article]
Titre : Radiative transfer modeling in structurally complex stands: towards a better understanding of parametrization Type de document : Article/Communication Auteurs : Frédéric André, Auteur ; Louis de Wergifosse, Auteur ; François de Coligny, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 92 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Belgique
[Termes IGN] couvert forestier
[Termes IGN] croissance des arbres
[Termes IGN] densité du feuillage
[Termes IGN] diamètre à hauteur de poitrine
[Termes IGN] estimation bayesienne
[Termes IGN] Fagus sylvatica
[Termes IGN] houppier
[Termes IGN] Leaf Mass per Area
[Termes IGN] modèle de croissance végétale
[Termes IGN] modèle de transfert radiatif
[Termes IGN] peuplement mélangé
[Termes IGN] photosynthèse
[Termes IGN] production primaire brute
[Termes IGN] production primaire nette
[Termes IGN] Quercus sessiliflora
[Termes IGN] structure d'un peuplement forestier
[Vedettes matières IGN] ForesterieRésumé : (auteur) Key message: The best options to parametrize a radiative transfer model change according to the response variable used for fitting. To predict transmitted radiation, the turbid medium approach performs much better than the porous envelop, especially when accounting for the intra-specific variations in leaf area density but crown shape has limited effects. When fitting with tree growth data, the porous envelop approach combined with the more complex crown shape provides better results. When using a joint optimization with both variables, the better options are the turbid medium and the more detailed approach for describing crown shape and leaf area density.
Context: Solar radiation transfer is a key process of tree growth dynamics in forest.
Aims: Determining the best options to parametrize a forest radiative transfer model in heterogeneous oak and beech stands from Belgium.
Methods: Calibration and evaluation of a forest radiative transfer module coupled to a spatially explicit tree growth model were repeated for different configuration options (i.e., turbid medium vs porous envelope to calculate light interception by trees, crown shapes of contrasting complexity to account for their asymmetry) and response variables used for fitting (transmitted radiation and/or tree growth data).
Results: The turbid medium outperformed the porous envelope approach. The more complex crown shapes enabling to account for crown asymmetry improved performances when including growth data in the calibration.
Conclusion: Our results provide insights on the options to select when parametrizing a forest radiative 3D-crown transfer model depending on the research or application objectives.Numéro de notice : A2021-768 Affiliation des auteurs : non IGN Thématique : FORET/MATHEMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s13595-021-01106-8 Date de publication en ligne : 26/10/2021 En ligne : https://doi.org/10.1007/s13595-021-01106-8 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99010
in Annals of Forest Science > vol 78 n° 4 (December 2021) . - n° 92[article]Spatio-temporal evolution, future trend and phenology regularity of net primary productivity of forests in Northeast China / Chunli Wang in Remote sensing, vol 12 n° 21 (November 2020)
[article]
Titre : Spatio-temporal evolution, future trend and phenology regularity of net primary productivity of forests in Northeast China Type de document : Article/Communication Auteurs : Chunli Wang, Auteur ; Qun’Ou Jiang, Auteur ; Xiangzheng Deng, Auteur ; et al., Auteur Année de publication : 2020 Article en page(s) : n° 3670 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse diachronique
[Termes IGN] analyse spatio-temporelle
[Termes IGN] changement climatique
[Termes IGN] Chine
[Termes IGN] croissance des arbres
[Termes IGN] développement durable
[Termes IGN] Normalized Difference Vegetation Index
[Termes IGN] phénologie
[Termes IGN] production primaire nette
[Termes IGN] variation saisonnière
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) Net Primary Productivity (NPP) is one of the significant indicators to measure environmental changes; thus, the relevant study of NPP in Northeast China, Asia, is essential to climate changes and ecological sustainable development. Based on the Global Production Efficiency (GLO-PEM) model, this study firstly estimated the NPP in Northeast China, from 2001 to 2019, and then analyzed its spatio-temporal evolution, future changing trend and phenology regularity. Over the years, the NPP of different forests type in Northeast China showed a gradual increasing trend. Compared with other different time stages, the high-value NPP (700–1300 gC·m−2·a−1) in Changbai Mountain, from 2017 to 2019, is more widely distributed. For instance, the NPP has an increasing rate of 6.92% compared to the stage of 2011–2015. Additionally, there was a significant advance at the start of the vegetation growth season (SOS), and a lag at the end of the vegetation growth season (EOS), from 2001 to 2019. Thus, the whole growth period of forests in Northeast China became prolonged with the change of phenology. Moreover, analysis on the sustainability of NPP in the future indicates that the reverse direction feature of NPP change will be slightly stronger than the co-directional feature, meaning that about 30.68% of the study area will switch from improvement to degradation. To conclude, these above studies could provide an important reference for the sustainable development of forests in Northeast China. Numéro de notice : A2020-719 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/rs12213670 Date de publication en ligne : 09/11/2020 En ligne : https://doi.org/10.3390/rs12213670 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96308
in Remote sensing > vol 12 n° 21 (November 2020) . - n° 3670[article]Climate change risk to forests in China associated with warming / Yunhe Yin in Scientific reports, vol 8 (2018)
[article]
Titre : Climate change risk to forests in China associated with warming Type de document : Article/Communication Auteurs : Yunhe Yin, Auteur ; Danyang Ma, Auteur ; Shaohong Wu, Auteur Année de publication : 2018 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] changement climatique
[Termes IGN] Chine
[Termes IGN] croissance des arbres
[Termes IGN] écologie forestière
[Termes IGN] forêt tropicale
[Termes IGN] production primaire nette
[Termes IGN] risque naturel
[Termes IGN] sécheresse
[Termes IGN] vingt-et-unième siècle
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) Variations in forest net primary productivity (NPP) reflects the combined effects of key climate variables on ecosystem structure and function, especially on the carbon cycle. We performed risk analysis indicated by the magnitude of future negative anomalies in NPP in comparison with the natural interannual variability to investigate the impact of future climatic projections on forests in China. Results from the multi-model ensemble showed that climate change risk of decreases in forest NPP would be more significant in higher emission scenario in China. Under relatively low emission scenarios, the total area of risk was predicted to decline, while for RCP8.5, it was predicted to first decrease and then increase after the middle of 21st century. The rapid temperature increases predicted under the RCP8.5 scenario would be probably unfavorable for forest vegetation growth in the long term. High-level risk area was likely to increase except RCP2.6. The percentage area at high risk was predicted to increase from 5.39% (2021–2050) to 27.62% (2071–2099) under RCP8.5. Climate change risk to forests was mostly concentrated in southern subtropical and tropical regions, generally significant under high emission scenario of RCP8.5, which was mainly attributed to the intensified dryness in south China. Numéro de notice : A2018-009 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1038/s41598-017-18798-6 En ligne : http://dx.doi.org/10.1038/s41598-017-18798-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89002
in Scientific reports > vol 8 (2018)[article]Modelling forest management within a global vegetation model - Part 1: Model structure and general behaviour / V. Bellassen in Ecological modelling, vol 221 n° 20 (octobre 2010)
[article]
Titre : Modelling forest management within a global vegetation model - Part 1: Model structure and general behaviour Type de document : Article/Communication Auteurs : V. Bellassen, Auteur ; G. Le Maire, Auteur ; Jean-François Dhôte, Auteur ; Philippe Ciais, Auteur ; Nicolas Viovy, Auteur Année de publication : 2010 Article en page(s) : pp 2458 - 2474 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] biomasse forestière
[Termes IGN] carbone
[Termes IGN] feuillu
[Termes IGN] modèle de simulation
[Termes IGN] modélisation de la forêt
[Termes IGN] production primaire netteMots-clés libres : ORCHIDEE Résumé : (auteur) This article describes a new forest management module (FMM) that explicitly simulates forest stand growth and management within a process-based global vegetation model (GVM) called ORCHIDEE. The net primary productivity simulated by ORCHIDEE is used as an input to the FMM. The FMM then calculates stand and management characteristics such as stand density, tree size distribution, tree growth, the timing and intensity of thinnings and clear-cuts, wood extraction and litter generated after thinning. Some of these variables are then fed back to ORCHIDEE. These computations are made possible with a distribution-based modelling of individual tree size. The model derives natural mortality from the relative density index (rdi), a competition index based on tree size and stand density. Based on the common forestry management principle of avoiding natural mortality, a set of rules is defined to calculate the recurrent intensity and frequency of forestry operations during the stand lifetime. The new-coupled model is called ORCHIDEE-FM (forest management). The general behaviour of ORCHIDEE-FM is analysed for a broadleaf forest in north-eastern France. Flux simulation throughout a forest rotation compare well with the literature values, both in absolute values and dynamics. Results from ORCHIDEE-FM highlight the impact of forest management on ecosystem C-cycling, both in terms of carbon fluxes and stocks. In particular, the average net ecosystem productivity (NEP) of 225 gC m−2 year−1 is close to the biome average of 311 gC m−2 year−1. The NEP of the “unmanaged” case is 40% lower, leading us to conclude that management explains 40% of the cumulated carbon sink over 150 years. A sensitivity analysis reveals 4 major avenues for improvement: a better determination of initial conditions, an improved allocation scheme to explain age-related decline in productivity, and an increased specificity of both the self-thinning curve and the biomass-diameter allometry. Numéro de notice : A2010-686 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1016/j.ecolmodel.2010.07.008 Date de publication en ligne : 20/08/2010 En ligne : https://doi.org/10.1016/j.ecolmodel.2010.07.008 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102452
in Ecological modelling > vol 221 n° 20 (octobre 2010) . - pp 2458 - 2474[article]Estimation of interannual variation in productivity of global vegetation using NDVI data / Z.M. Chen in International Journal of Remote Sensing IJRS, vol 25 n° 16 (August 2004)
[article]
Titre : Estimation of interannual variation in productivity of global vegetation using NDVI data Type de document : Article/Communication Auteurs : Z.M. Chen, Auteur ; I.S. Babiker, Auteur ; et al., Auteur Année de publication : 2004 Article en page(s) : pp 3139 - 3159 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] analyse diachronique
[Termes IGN] bilan du carbone
[Termes IGN] biosphère
[Termes IGN] changement climatique
[Termes IGN] dioxyde de carbone
[Termes IGN] forêt tempérée
[Termes IGN] forêt tropicale
[Termes IGN] image NOAA-AVHRR
[Termes IGN] impact sur l'environnement
[Termes IGN] Normalized Difference Vegetation Index
[Termes IGN] production primaire nette
[Termes IGN] répartition géographique
[Termes IGN] variation saisonnièreRésumé : (Auteur) The interannual variation of global vegetation net primary production (NPP), which is crucial to understanding the role of terrestrial biosphere in the global carbon cycle, is still poorly understood. Currently, remote sensing emerges as a useful tool for estimating NPP through monitoring global vegetation distribution and growth. The objective of this study was to utilize the multi-year monthly Normalized Difference Vegetation Index (NDVI) dataset of 1987-1997 from the Advanced Very High Resolution Radiometer (AVHRR) to investigate the interannual variation in productivity of global vegetation due to climate variation, human activities, and environmental events. A decision tree algorithm based on simple metrics (minimum, maximum, mean and amplitude) was employed to classify the global vegetation from NDVI data and obtain the annual vegetation growth areas. Then, annual NPP was computed using the annual vegetation growth areas and the predefined NPP coefficients given in a 1990 Intergovernmental Panel on Climate Change (IPCQ) report. The NPP exhibited a slightly increasing trend through the 11 years. However, interannual variations were observed to be mainly determined by variation in growth of tropical and temperate evergreen forests. These fluctuations were consistently correlated to El Niño/La Niña events. Although the interannual variation in primary productivity of global vegetation is expected to influence the atmospheric C02 concentration over the one-decade period, it is unlikely to have solely caused the anomalously low growth in 1992-1993. The adopted methodology enabled close examination of variability in vegetation growth at the biome scale as well as at global scale. Numéro de notice : A2004-301 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/0143116032000160435 En ligne : https://doi.org/10.1080/0143116032000160435 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26828
in International Journal of Remote Sensing IJRS > vol 25 n° 16 (August 2004) . - pp 3139 - 3159[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 080-04141 RAB Revue Centre de documentation En réserve L003 Disponible Estimating fragmentation effects on simulated forest net primary productivity derived from satellite imagery / Nicholas C. Coops in International Journal of Remote Sensing IJRS, vol 25 n° 4 (February 2004)Permalink