Centre dedocumentation
scientifique

A continuous change tracker model for remote sensing time series reconstruction / Yangjian Zhang in Remote sensing, vol 14 n° 9 (May-1 2022)  

Public [article]  inRemote sensing > vol 14 n° 9 (May-1 2022) . - n° 2280 Titre : A continuous change tracker model for remote sensing time series reconstruction Type de document : Article/Communication Auteurs : Yangjian Zhang, Auteur ; Li Wang, Auteur ; Yuanhuizi He, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : n° 2280 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] algorithme de filtrage [Termes IGN] analyse harmonique [Termes IGN] compression d'image [Termes IGN] détection de changement [Termes IGN] extraction de traits caractéristiques [Termes IGN] Leaf Area Index [Termes IGN] Normalized Difference Vegetation Index [Termes IGN] phénologie [Termes IGN] production primaire brute [Termes IGN] reconstruction d'image [Termes IGN] réflectance de surface [Termes IGN] série temporelle Résumé : (auteur) It is hard for current time series reconstruction methods to achieve the balance of high-precision time series reconstruction and explanation of the model mechanism. The goal of this paper is to improve the reconstruction accuracy with a well-explained time series model. Thus, we developed a function-based model, the CCTM (Continuous Change Tracker Model) model, that can achieve high precision in time series reconstruction by tracking the time series variation rate. The goal of this paper is to provide a new solution for high-precision time series reconstruction and related applications. To test the reconstruction effects, the model was applied to four types of datasets: normalized difference vegetation index (NDVI), gross primary productivity (GPP), leaf area index (LAI), and MODIS surface reflectance (MSR). Several new observations are as follows. First, the CCTM model is well explained and based on the second-order derivative theorem, which divides the yearly time series into four variation types including uniform variations, decelerated variations, accelerated variations, and short-periodical variations, and each variation type is represented by a designed function. Second, the CCTM model provides much better reconstruction results than the Harmonic model on the NDVI, GPP, MSR, and LAI datasets for the seasonal segment reconstruction. The combined use of the Savitzky–Golay filter and the CCTM model is better than the combinations of the Savitzky–Golay filter with other models. Third, the Harmonic model has the best trend-fitting ability on the yearly time series dataset, with the highest R-Square and the lowest RMSE among the four function fitting models. However, with seasonal piecewise fitting, the four models all achieved high accuracy, and the CCTM performs the best. Fourth, the CCTM model should also be applied to time series image compression, two compression patterns with 24 coefficients and 6 coefficients respectively are proposed. The daily MSR dataset can achieve a compression ratio of 15 by using the 6-coefficients method. Finally, the CCTM model also has the potential to be applied to change detection, trend analysis, and phenology and seasonal characteristics extractions. Numéro de notice : A2022-384 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.3390/rs14092280 Date de publication en ligne : 09/05/2022 En ligne : https://doi.org/10.3390/rs14092280 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100662 [article]

Radiative transfer modeling in structurally complex stands: towards a better understanding of parametrization / Frédéric André in Annals of Forest Science [en ligne], vol 78 n° 4 (December 2021)  

Public [article]  inAnnals of Forest Science [en ligne] > vol 78 n° 4 (December 2021) . - n° 92 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] Foresterie Résumé : (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 [article]

Estimation of biomass increase and CUE at a young temperate scots pine stand concerning drought occurrence by combining eddy covariance and biometric methods / Paulina Dukat in Forests, vol 12 n° 7 (July 2021)  

Public [article]  inForests > vol 12 n° 7 (July 2021) . - n° 867 Titre : Estimation of biomass increase and CUE at a young temperate scots pine stand concerning drought occurrence by combining eddy covariance and biometric methods Type de document : Article/Communication Auteurs : Paulina Dukat, Auteur ; Klaudia Ziemblińska, Auteur ; Janusz Olejnik, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 867 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] biomasse forestière [Termes IGN] changement climatique [Termes IGN] covariance [Termes IGN] diamètre à hauteur de poitrine [Termes IGN] dioxyde de carbone [Termes IGN] indice de végétation [Termes IGN] inventaire forestier (techniques et méthodes) [Termes IGN] Pinus sylvestris [Termes IGN] Pologne [Termes IGN] production primaire brute [Termes IGN] puits de carbone [Termes IGN] sécheresse [Vedettes matières IGN] Inventaire forestier Résumé : (auteur) The accurate estimation of an increase in forest stand biomass has remained a challenge. Traditionally, in situ measurements are done by inventorying a number of trees and their biometric parameters such as diameter at the breast height (DBH) and height; sometimes these are complemented by carbon (C) content studies. Here we present the estimation of net primary productivity (NPP) over a two years period (2019–2020) at a 25-year-old Scots pine stand. Research was based on allometric equations made by direct biomass analysis (tree extraction) and carbon content estimations in individual components of sampled trees, combined with a series of stem diameter increments recorded by a network of band dendrometers. Site-specific allometric equations were obtained using two different approaches: using the whole tree biomass vs DBH (M1), and total dry biomass-derived as a sum of the results from individual tree components’ biomass vs DBH (M2). Moreover, equations for similar forest stands from the literature were used for comparison. Gross primary productivity (GPP) estimated from the eddy-covariance measurements allowed the calculation of carbon use efficiency (CUE = NPP/GPP). The two investigated years differed in terms of the sum and patterns of precipitation distribution, with a moderately dry year of 2019 that followed the extremely dry 2018, and the relatively average year of 2020. As expected, a higher increase in biomass was recorded in 2020 compared to 2019, as determined by both allometric equations based on in situ and literature data. For the former approach, annual NPP estimates reached ca. 2.0–2.1 t C ha−1 in 2019 and 2.6–2.7 t C ha−1 in 2020 depending on the “in situ equations” (M1-M2) used, while literature-derived equations for the same site resulted in NPP values ca. 20–30% lower. CUE was higher in 2020, which resulted from a higher NPP total than in 2019, with lower summer and spring GPP in 2020. However, the CUE values were lower than those reported in the literature for comparable temperate forest stands. A thorough analysis of the low CUE value would require a full interpretation of interrelated physiological responses to extreme conditions. Numéro de notice : A2021-641 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.3390/f12070867 Date de publication en ligne : 30/06/2021 En ligne : https://doi.org/10.3390/f12070867 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98313 [article]

The Salem simulator version 2.0: a tool for predicting the productivity of pure and mixed stands and simulating management operations / Raphaël Aussenac in Open Research Europe, vol 2021 ([01/03/2021])  

Public [article]  inOpen Research Europe > vol 2021 [01/03/2021] Titre : The Salem simulator version 2.0: a tool for predicting the productivity of pure and mixed stands and simulating management operations Type de document : Article/Communication Auteurs : Raphaël Aussenac, Auteur ; Thomas Pérot, Auteur ; Mathieu Fortin, Auteur ; François de Coligny, Auteur ; Jean-Matthieu Monnet, Auteur ; Patrick Vallet, Auteur Année de publication : 2021 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] biomasse [Termes IGN] composition d'un peuplement forestier [Termes IGN] modèle de simulation [Termes IGN] modélisation de la forêt [Termes IGN] peuplement mélangé [Termes IGN] peuplement pur [Termes IGN] production primaire brute [Termes IGN] productivité biologique [Vedettes matières IGN] Foresterie Résumé : (auteur) A growing body of research suggests mixed-species stands are generally more productive than pure stands. However, this effect of mixture depends on species assemblages and environmental conditions and forest managers often lack tools to assess the potential benefit of shifting from pure to mixed stands. Here we present Salem, a simulator filling this gap. Salem predicts the dynamics of pure and mixed even-aged stands and makes it possible to simulate management operations. Its purpose is to be a decision support tool for forest managers and stakeholders as well as for policy makers. It is also designed to conduct virtual experiments and help answer research questions. In Salem, we parameterised the growth in pure stand of 12 common tree species of Europe and we assessed the effect of mixture on species growth for 24 species pairs (made up of the 12 species mentioned above). Thus, Salem makes it possible to compare the productivity of 36 different pure and mixed stands depending on environmental conditions and user-defined management strategies. Salem is essentially based on the analysis of National Forest Inventory data. A major outcome of this analysis is that we found species mixture most often increases species growth, in particular at the poorest sites. Independently from the simulator, foresters and researchers can also consider using the species-specific models that constitute Salem: the growth models including or excluding mixture effect, the bark models, the diameter distribution models, the circumference-height relationship models, as well as the volume equations for the 12 parameterised species. Salem runs on Windows, Linux, or Mac. Its user-friendly graphical user interface makes it easy to use for non-modellers. Finally, it is distributed under a LGPL license and is therefore free and open source. Numéro de notice : A2021-507 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.12688/openreseurope.13671.1 Date de publication en ligne : 04/06/2021 En ligne : https://doi.org/10.12688/openreseurope.13671.1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98152 [article]

Pure and even-aged forestry of fast growing conifers under climate change: on the need of a silvicultural paradigm shift / Clémentine Ols in Environmental Research Letters, vol 16 n° 2 (February 2021)    

Public [article]  inEnvironmental Research Letters > vol 16 n° 2 (February 2021) . - n° 024030 Titre : Pure and even-aged forestry of fast growing conifers under climate change: on the need of a silvicultural paradigm shift Type de document : Article/Communication Auteurs : Clémentine Ols , Auteur ; Jean-Daniel Bontemps , Auteur Année de publication : 2021 Projets : ARBRE/RESFORCLIM / Article en page(s) : n° 024030 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] changement climatique [Termes IGN] croissance végétale [Termes IGN] inventaire forestier national (données France) [Termes IGN] Picea abies [Termes IGN] Pinophyta [Termes IGN] Pinus sylvestris [Termes IGN] plantation forestière [Termes IGN] politique forestière [Termes IGN] Préalpes (Europe) [Termes IGN] production primaire brute [Termes IGN] Pseudotsuga menziesii [Termes IGN] résilience écologique [Termes IGN] sylviculture [Termes IGN] Union Européenne [Vedettes matières IGN] Economie forestière Résumé : (auteur) Pure and even-aged (PEA) forests of fast growing conifer species have for long been key providers of industrial raw material. Despite recent concern regarding their greater sensitivity to major natural disturbances, their impacts onto biodiversity and their funding efficiency, PEA conifer forests could remain a major economic target given the ongoing European strategy for bioeconomy. These forests are encountered across contrasted climates and in both native and introduced contexts across Europe giving rise to high uncertainties regarding their growth responses to current climate change. Using the French national forest inventory data, we inquired the radial growth of eight major conifer species in European forestry across 16 regional native and introduced PEA forest systems (n > 10,000 trees). Growth trends over the 2006-2016 period exhibited a negative association with absolute growth level in 2006, with strongest negative trends found for emblematic PEA forestry species (e.g. Norway spruce and Douglas-fir), and strongest positive trends for pine species (e.g. Scots pine). While the greater growth rate advantage of some species may shorten rotation and lower risk exposures for future decades, recent lowered productivity may affect the forest sector in the long run. The prevalence of PEA forests across European forest landscapes and their increasingly reported lower resilience to climate change compared to more complex forest systems call for the establishment of a long-term European forest policy strategy. Maintaining the environmental, social and economic benefits of forests should remain a priority in the European agenda, regardless of the financial costs at stake. Numéro de notice : A2021-060 Affiliation des auteurs : LIF (2020- ) Autre URL associée : vers HAL Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1088/1748-9326/abd6a7 Date de publication en ligne : 24/12/2020 En ligne : https://doi.org/10.1088/1748-9326/abd6a7 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96732 [article]

Documents numériques

peut être téléchargé Pure and even-aged forestry ... - postprint Adobe Acrobat PDF

An infrastructure perspective for enhancing multi-functionality of forests: A conceptual modeling approach / Mojtaba Houballah in Earth' future, vol 9 n° 1 (January 2021)  

Permalink

State of Europe's forests 2020 / Forest Europe (2021)  

Permalink

Good things take time : Diversity effects on tree growth shift from negative to positive during stand development in boreal forests / Tommaso Jucker in Journal of ecology, vol 108 n° 6 (November 2020)  

Permalink

CO2 fertilization, transpiration deficit and vegetation period drive the response of mixed broadleaved forests to a changing climate in Wallonia / Louis de Wergifosse in Annals of Forest Science [en ligne], vol 77 n° 3 (September 2020)  

Permalink

Using spectral indices to estimate water content and GPP in sphagnum moss and other peatland vegetation / Kirsten J. Lees in IEEE Transactions on geoscience and remote sensing, vol 58 n° 7 (July 2020)  

Permalink

Impact of precipitation, air temperature and abiotic emissions on gross primary production in Mediterranean ecosystems in Europe / S. Bartsch in European Journal of Forest Research, vol 139 n° 1 (February 2020)  

Permalink

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)  

Permalink

Estimating net biomass production and loss from repeated measurements of trees in forests and woodlands: Formulae, biases and recommendations / Takashi S. Kohyama in Forest ecology and management, vol 433 (15 February 2019)  

Permalink

A new algorithm predicting the end of growth at five evergreen conifer forests based on nighttime temperature and the enhanced vegetation index / Huanhuan Yuan in ISPRS Journal of photogrammetry and remote sensing, vol 144 (October 2018)  

Permalink

Seasonal time-course of the above ground biomass production efficiency in beech trees (Fagus sylvatica L.) / Laura Heid in Annals of Forest Science [en ligne], vol 75 n° 1 (March 2018)  

Permalink