Documents disponibles dans cette catégorie (35)
Ajouter le résultat dans votre panier Visionner les documents numériques Affiner la recherche Interroger des sources externes
Etendre la recherche sur niveau(x) vers le bas
Surface modelling of forest aboveground biomass based on remote sensing and forest inventory data / Xiaofang Sun in Geocarto international, vol 36 n° 14 ([01/08/2021])
Titre : Surface modelling of forest aboveground biomass based on remote sensing and forest inventory data Type de document : Article/Communication Auteurs : Xiaofang Sun, Auteur ; Bai Li, Auteur ; Zhengping Du, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : pp 1549 - 1564 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] biomasse aérienne
[Termes IGN] biomasse forestière
[Termes IGN] carbone
[Termes IGN] carte de la végétation
[Termes IGN] classification barycentrique
[Termes IGN] classification par forêts aléatoires
[Termes IGN] classification par séparateurs à vaste marge
[Termes IGN] données IceSat-Glas
[Termes IGN] données lidar
[Termes IGN] données multisources
[Termes IGN] Geoscience Laser Altimeter System
[Termes IGN] image Terra-MODIS
[Termes IGN] inventaire forestier étranger (données)
[Termes IGN] Kiangsi (Chine)
[Termes IGN] krigeage
[Termes IGN] modèle numérique de surface
[Termes IGN] Normalized Difference Vegetation Index
[Termes IGN] régression des moindres carrés partiels
Résumé : (auteur) An accurate estimation of forest aboveground biomass (AGB) is important for carbon accounting. In this study, six methods, including partial least squares regression, regression kriging, k-nearest neighbour, support vector machines, random forest and high accuracy surface modelling (HASM), were used to simulate forest AGB. Forest AGB was mapped by combining Geoscience Laser Altimeter System data, optical imagery and field inventory data. The Normalized Difference Vegetation Index (NDVI) and Wide Dynamic Range Vegetation Index (WDRVI0.2) of September and October, which had a stronger correlation with forest AGB than that of the peak growing season, were selected as predictor variables, along with tree cover percentage and three GLAS-derived parameters. The results of the different methods were evaluated. The HASM model had the best modelling accuracy (small MAE, RMSE, NRMSE, RMSV and NMSE and large R2). A forest AGB map of the study area was generated using the optimal model. Numéro de notice : A2021-555 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106049.2019.1655799 Date de publication en ligne : 28/08/2019 En ligne : https://doi.org/10.1080/10106049.2019.1655799 Format de la ressource électronique : URL article Permalink :
in Geocarto international > vol 36 n° 14 [01/08/2021] . - pp 1549 - 1564[article]Forest gaps retard carbon and nutrient release from twig litter in alpine forest ecosystems / Bo Tan in European Journal of Forest Research, vol 139 n° 1 (February 2020)
Titre : Forest gaps retard carbon and nutrient release from twig litter in alpine forest ecosystems Type de document : Article/Communication Auteurs : Bo Tan, Auteur ; Jian Zhang, Auteur ; Wanqin Yang, Auteur ; et al., Auteur Année de publication : 2020 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] azote
[Termes IGN] carbone
[Termes IGN] Chine
[Termes IGN] dégel
[Termes IGN] écosystème forestier
[Termes IGN] forêt alpestre
[Termes IGN] gelée
[Termes IGN] hiver
[Termes IGN] litière
[Termes IGN] nutriment végétal
[Termes IGN] phosphore
[Termes IGN] température au sol
[Vedettes matières IGN] Botanique
Résumé : (auteur) Changes in soil microclimate driven by forest gaps have accelerated mass loss and carbon (C), nitrogen (N) and phosphorus (P) release from foliar litter in alpine forests ecosystems. Yet, it is unclear whether the same gap effect occurs in twig litter decomposition. A 4-year decomposition experiment was conducted in an alpine forest to explore the litter mass loss and C, N and P release among four gap treatments, including (1) closed canopy, (2) small gap ( Numéro de notice : A2020-229 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1007/s10342-019-01229-8 Date de publication en ligne : 12/09/2019 En ligne : https://doi.org/10.1007/s10342-019-01229-8 Format de la ressource électronique : url article Permalink :
in European Journal of Forest Research > vol 139 n° 1 (February 2020)[article]Increasing temperatures over an 18-year period shortens growing season length in a beech (Fagus sylvatica L.)-dominated forest / Quentin Hurdebise in Annals of Forest Science [en ligne], Vol 76 n° 3 (September 2019)
Titre : Increasing temperatures over an 18-year period shortens growing season length in a beech (Fagus sylvatica L.)-dominated forest Type de document : Article/Communication Auteurs : Quentin Hurdebise, Auteur ; Marc Aubinet, Auteur ; Bernard Heinesch, Auteur ; Caroline Vincke, Auteur Année de publication : 2019 Article en page(s) : 12 p. Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Belgique
[Termes IGN] carbone
[Termes IGN] changement climatique
[Termes IGN] écosystème forestier
[Termes IGN] Fagus sylvatica
[Termes IGN] phénologie
[Termes IGN] production primaire brute
[Termes IGN] température de l'air
[Vedettes matières IGN] Végétation et changement climatique
Résumé : (auteur) Key message: Using long-term measurements in a mature beech (Fagus sylvatica L.)-dominated forest located in east Belgium, this paper showed that spring and autumn temperature increases during the last two decades led to an earlier end and a shortening of the growing season. These phenological shifts impact negatively but not significantly the forest annual net ecosystem productivity.
Context: The mechanisms controlling temperate forest phenology are not fully understood nor are the impacts of climate change and the consequences for forest productivity.
Aims: The aim of this paper is to contribute to the understanding of how temperate forest phenology and net ecosystem productivity (NEP) interplay and respond to temperature and its evolution.
Methods: Indicators of leaf phenology and productivity dynamics at the start and the end of the growing season, as well as combinations of these indicators (length of the growing season), were derived from a long-term (1997–2014) dataset of eddy covariance and light transmission measurements taken over a mature beech-dominated temperate forest.
Results: The start and the end of the growing season were correlated to spring (and autumn, for the end) temperatures. Despite no trends in annual average temperatures being detected during the observation period, April and November temperatures significantly increased. As a result, an earlier but slower start and an earlier end, inducing a shorter length of the growing season, were observed over the studied period. The first shift positively impacts the mixed forest NEP but is mainly related to the presence of conifers in the subplot. The earlier end of the growing season, more related to beech phenology, negatively impacts the forest NEP. Overall, these two effects partially compensate each other, leading to a non-significant impact on NEP.
Conclusion: Increasing temperatures over the 18-year studied period shortened the growing season length, without affecting significantly the mixed forest NEP. However, as beeches are only affected by the earlier end of the growing season, this suggests a phenologically driven beech productivity reduction in the forest.
Numéro de notice : A2019-305 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s13595-019-0861-8 Date de publication en ligne : 29/07/2019 En ligne : https://doi.org/10.1007/s13595-019-0861-8 Format de la ressource électronique : URL article Permalink :
in Annals of Forest Science [en ligne] > Vol 76 n° 3 (September 2019) . - 12 p.[article]Biodiversity effects on ecosystem functioning in a 15-year grassland experiment: patterns, mechanisms, and open questions / Wolfgang W. Weisser in Basic and Applied Ecology, vol 23 (September 2017)
Titre : Biodiversity effects on ecosystem functioning in a 15-year grassland experiment: patterns, mechanisms, and open questions Type de document : Article/Communication Auteurs : Wolfgang W. Weisser, Auteur ; Christiane Roscher, Auteur ; Sebastian Meyer, Auteur ; et al., Auteur Année de publication : 2017 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Ecologie
[Termes IGN] azote
[Termes IGN] biomasse
[Termes IGN] carbone
[Termes IGN] écosystème
[Termes IGN] gaz à effet de serre
[Termes IGN] nutriment végétal
[Termes IGN] placette d'échantillonnage
[Termes IGN] potassium
[Termes IGN] puits de carbone
[Termes IGN] richesse floristique
[Termes IGN] sol
[Termes IGN] stabilité
Résumé : (auteur) In the past two decades, a large number of studies have investigated the relationship between biodiversity and ecosystem functioning, most of which focussed on a limited set of ecosystem variables. The Jena Experiment was set up in 2002 to investigate the effects of plant diversity on element cycling and trophic interactions, using a multi-disciplinary approach. Here, we review the results of 15 years of research in the Jena Experiment, focussing on the effects of manipulating plant species richness and plant functional richness. With more than 85,000 measures taken from the plant diversity plots, the Jena Experiment has allowed answering fundamental questions important for functional biodiversity research.
First, the question was how general the effect of plant species richness is, regarding the many different processes that take place in an ecosystem. About 45% of different types of ecosystem processes measured in the ‘main experiment’, where plant species richness ranged from 1 to 60 species, were significantly affected by plant species richness, providing strong support for the view that biodiversity is a significant driver of ecosystem functioning. Many measures were not saturating at the 60-species level, but increased linearly with the logarithm of species richness. There was, however, great variability in the strength of response among different processes. One striking pattern was that many processes, in particular belowground processes, took several years to respond to the manipulation of plant species richness, showing that biodiversity experiments have to be long-term, to distinguish trends from transitory patterns. In addition, the results from the Jena Experiment provide further evidence that diversity begets stability, for example stability against invasion of plant species, but unexpectedly some results also suggested the opposite, e.g. when plant communities experience severe perturbations or elevated resource availability. This highlights the need to revisit diversity-stability theory.
Second, we explored whether individual plant species or individual plant functional groups, or biodiversity itself is more important for ecosystem functioning, in particular biomass production. We found strong effects of individual species and plant functional groups on biomass production, yet these effects often occurred mostly in addition to, but not instead of, effects of plant species richness.
Third, the Jena Experiment assessed the effect of diversity on multitrophic interactions. The diversity of most organisms responded positively to increases in plant species richness, and the effect was stronger for above- than for belowground organisms, and stronger for herbivores than for carnivores or detritivores. Thus, diversity begets diversity. In addition, the effect on organismic diversity was stronger than the effect on species abundances.
Fourth, the Jena Experiment aimed to assess the effect of diversity on N, P and C cycling and the water balance of the plots, separating between element input into the ecosystem, element turnover, element stocks, and output from the ecosystem. While inputs were generally less affected by plant species richness, measures of element stocks, turnover and output were often positively affected by plant diversity, e.g. carbon storage strongly increased with increasing plant species richness. Variables of the N cycle responded less strongly to plant species richness than variables of the C cycle.
Fifth, plant traits are often used to unravel mechanisms underlying the biodiversity-ecosystem functioning relationship. In the Jena Experiment, most investigated plant traits, both above- and belowground, were plastic and trait expression depended on plant diversity in a complex way, suggesting limitation to using database traits for linking plant traits to particular functions.
Sixth, plant diversity effects on ecosystem processes are often caused by plant diversity effects on species interactions. Analyses in the Jena Experiment including structural equation modelling suggest complex interactions that changed with diversity, e.g. soil carbon storage and greenhouse gas emission were affected by changes in the composition and activity of the belowground microbial community. Manipulation experiments where particular organisms, e.g. belowground invertebrates, were excluded from plots in split-plot experiments, supported the important role of the biotic component for element and water fluxes.
Seventh, the Jena Experiment aimed to put the results into the context of agricultural practices in managed grasslands. The effect of increasing plant species richness from 1 to 16 species on plant biomass was, in absolute terms, as strong as the effect of a more intensive grassland management, using fertiliser and increasing mowing frequency. Potential bioenergy production from high-diversity plots was similar to that of conventionally used energy crops. These results suggest that diverse ‘High Nature Value Grasslands’ are multifunctional and can deliver a range of ecosystem services including production-related services.
A final task was to assess the importance of potential artefacts in biodiversity–ecosystem functioning relationships, caused by the weeding of the plant community to maintain plant species composition. While the effort (in hours) needed to weed a plot was often negatively related to plant species richness, species richness still affected the majority of ecosystem variables. Weeding also did not negatively affect monoculture performance; rather, monocultures deteriorated over time for a number of biological reasons, as shown in plant-soil feedback experiments.
To summarize, the Jena Experiment has allowed for a comprehensive analysis of the functional role of biodiversity in an ecosystem. A main challenge for future biodiversity research is to increase our mechanistic understanding of why the magnitude of biodiversity effects differs among processes and contexts. It is likely that there will be no simple answer. For example, among the multitude of mechanisms suggested to underlie the positive plant species richness effect on biomass, some have received limited support in the Jena Experiment, such as vertical root niche partitioning. However, others could not be rejected in targeted analyses. Thus, from the current results in the Jena Experiment it seems likely that the positive biodiversity effect results from several mechanisms acting simultaneously in more diverse communities, such as reduced pathogen attack, the presence of more plant growth promoting organisms, less seed limitation, and increased trait differences leading to complementarity in resource uptake. Distinguishing between different mechanisms requires careful testing of competing hypotheses. Biodiversity research has matured such that predictive approaches testing particular mechanisms are now possible.
Numéro de notice : A2017-352 Affiliation des auteurs : non IGN Thématique : BIODIVERSITE/FORET Nature : Article DOI : 10.1016/j.baae.2017.06.002 Date de publication en ligne : 26/06/2017 En ligne : https://doi.org/10.1016/j.baae.2017.06.002 Format de la ressource électronique : URL article Permalink :
in Basic and Applied Ecology > vol 23 (September 2017)[article]vol 90 n° 1 - mars 2013 - Réchauffement climatique : un carbone qui sent le soufre (Bulletin de Bulletin de l'association de géographes français, Géographies) / M. Tabeaud
[n° ou bulletin]
est un bulletin de Bulletin de l'association de géographes français, Géographies / Association de géographes français (1924 -)
Titre : vol 90 n° 1 - mars 2013 - Réchauffement climatique : un carbone qui sent le soufre Type de document : Périodique Auteurs : M. Tabeaud, Éditeur scientifique ; Association de géographes français, Auteur Année de publication : 2013 Importance : 172 p. Langues : Français (fre) Descripteur : [Vedettes matières IGN] Géographie générale
[Termes IGN] carbone
[Termes IGN] changement climatique
[Termes IGN] collectivité territoriale
[Termes IGN] plan d'exposition aux risques
Numéro de notice : 017-201301 Thématique : FORET Nature : Numéro de périodique Permalink : [n° ou bulletin]
RéservationRéserver ce document
Code-barres Cote Support Localisation Section Disponibilité 017-2013011 SL Revue Centre de documentation Revues en salle DisponibleBois-énergie : une fausse « bonne solution » pour atténuer l'effet de serre / Philippe Leturcq in Forêt entreprise, n° 192 (mai 2010/3)PermalinkUsing landscape characteristics to define an adjusted distance metric for improving kriging interpolations / S. Lyon in International journal of geographical information science IJGIS, vol 24 n° 5-6 (may 2010)PermalinkLes inventaires forestiers nationaux, observatoires et tableaux de bord permanent des espaces boisés, journée d'étude, 12 mai 2010, Gembloux, Belgique / Jacques Rondeux (2010)PermalinkLes marchés du carbone forestier : quelle est la place de la forêt dans les marchés du carbone ? Quelles sont les tendances à anticiper ? Comment financer un projet et vendre des crédits ? / Clément Chenost (2010)PermalinkRapport Puech in Forêts de France, n° 528 (novembre 2009)PermalinkLa taxe carbone et le ministre Michel Mercier s'invitent chez Eurochêne / Bernard Rérat in La Forêt Privée, n° 309 (septembre-octobre 2009)PermalinkInfluence of microstructured carbon materials on Sequoia sempervirens (D. Don.) Endl. in vitro culture / Raluca Stoiculescu in Annals of forest research, vol 52 n° 1 (January 2009)PermalinkLaurent Valiergue, directeur origination chez Orbeo / Fabienne Tisserand in Le Bois International : l'officiel du bois [édition verte], vol 2008 n° 42 (13 décembre 2008)PermalinkLe bois mort, source de vie / Marc Laporte in Forêt entreprise, n° 183 (novembre 2008)PermalinkLa forêt et la lutte contre le changement climatique / Marianne Rubio in Rendez-vous techniques, n° 20 (mai 2008)Permalink