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Climate and ungulate browsing impair regeneration dynamics in spruce-fir-beech forests in the French Alps / Mithila Unkule in Annals of Forest Science [en ligne], vol 79 n° 1 (2022)  

Public [article]  inAnnals of Forest Science [en ligne] > vol 79 n° 1 (2022) . - n° 11 Titre : Climate and ungulate browsing impair regeneration dynamics in spruce-fir-beech forests in the French Alps Type de document : Article/Communication Auteurs : Mithila Unkule, Auteur ; Christian Piedallu, Auteur ; Philippe Balandier, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : n° 11 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Abies alba [Termes IGN] Alpes (France) [Termes IGN] Cervidae [Termes IGN] Fagus sylvatica [Termes IGN] faune locale [Termes IGN] hauteur des arbres [Termes IGN] humidité du sol [Termes IGN] Jura, massif du [Termes IGN] Picea abies [Termes IGN] placette d'échantillonnage [Termes IGN] régénération (sylviculture) [Termes IGN] sécheresse [Vedettes matières IGN] Végétation et changement climatique Résumé : (auteur) Key message: Different components of water balance and temperature reduce density and height growth of saplings of Picea abies (L.) H. Karst (Norway spruce), Abies alba Mill. (silver fir) and Fagus sylvatica L. (European beech) in mixed uneven-aged forests in the French Alps and Jura mountains. Ungulate browsing is an additional pressure on fir and beech that could jeopardise the renewal of these species in the future. Context: The uncertainty in tree recruitment rates raises questions about the factors affecting regeneration processes in forests. Factors such as climate, light, competition and ungulate browsing pressure may play an important role in determining regeneration, forest structures and thus future forest composition. Aims: The objective of this study was to quantify sapling densities and height increments of spruce, fir and beech and to identify dominant environmental variables influencing them in mixed uneven-aged forests in the French Alps and Jura mountains. Methods: Sapling height increment and density were recorded in 152 plots, and non-linear mixed models were obtained to establish relations between them and environmental factors known to affect regeneration, namely altitude, slope, aspect, canopy openness, soil characteristics, temperature, precipitation and ungulate browsing. Results: Regeneration density, varying from 0 to 7 saplings per m 2, decreased with sapling height and was also negatively affected for spruce by PET, but positively for fir by precipitation and for beech by mean annual soil water content. Height increment reached up to 50 cm annually, increasing with sapling height and canopy openness and decreasing under high maximum summer temperatures for spruce and beech. The statistical effect of different environmental variables varied slightly among species but trends were quite similar. Additionally, ungulate browsing was high, with fir being the most intensely browsed, followed closely by beech, while spruce was rarely browsed. Conclusions: All these results suggest that more temperature warming and a decrease in water availability could negatively impact sapling growth and density in the three species, with possible reduction of forest renewal fluxes. The observed increase of ungulate populations leading to increased browsing could be particularly detrimental to fir saplings. Numéro de notice : A2022-509 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1186/s13595-022-01126-y Date de publication en ligne : 23/03/2022 En ligne : https://doi.org/10.1186/s13595-022-01126-y Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101045 [article]

Effect of riparian soil moisture on bacterial, fungal and plant communities and microbial decomposition rates in boreal stream-side forests / M.J. Annala in Forest ecology and management, vol 519 (1 September 2022)  

Public [article]  inForest ecology and management > vol 519 (1 September 2022) . - n° 120344 Titre : Effect of riparian soil moisture on bacterial, fungal and plant communities and microbial decomposition rates in boreal stream-side forests Type de document : Article/Communication Auteurs : M.J. Annala, Auteur ; K. Lehosmaa, Auteur ; S.H.K. Ahonen, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : n° 120344 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] cours d'eau [Termes IGN] écosystème forestier [Termes IGN] Finlande [Termes IGN] forêt boréale [Termes IGN] forêt ripicole [Termes IGN] Fungi [Termes IGN] humidité du sol [Termes IGN] micro-organisme [Termes IGN] plante ripicole [Termes IGN] taxinomie [Termes IGN] zone tampon [Vedettes matières IGN] Ecologie forestière Résumé : (auteur) Riparian habitats of boreal forests are considered as hotspots for biochemical processes and biodiversity, and varying width riparian buffers have been proposed to protect species diversity of the riparian forests. However, evidence of the role of soil moisture variation in shaping riparian biodiversity and ecosystem functioning remain scarce particularly regarding belowground diversity. We studied how distance from the stream and soil moisture of the riparian zone affected species richness and community composition of plants, bacteria, and fungi as well as microbial decomposition rates. Using a split-plot design with a plant survey and amplicon sequencing for microorganisms we identified taxa associated with different categories of moisture and distance from the stream along six headwater stream-sides in middle boreal forests in Northern Finland. Tea-bag Index was used to assess the decomposition rates. PERMANOVA and linear mixed-effect models were used to analyze the data. Variation in riparian soil moisture influenced species composition and richness of plants and bacteria. Plant communities also changed from herbaceous dominated to shrub dominated with increasing distance from the stream. Fungal communities, however, did not respond to soil moisture or distance from the stream, and there were only slight differences in fungal trophic guilds among moisture and distance categories. Decomposition of organic material by microorganisms was faster adjacent to the stream than further away, and moist riparian areas had higher decomposition rates than drier ones. Decomposition rates were positively related to pH, Ca, Mg and NH4 and soil temperature. Synthesis and applications We show that above- and belowground diversity and microbial decomposition are associated to soil moisture at riparian sites supporting the idea of leaving wider unmanaged buffers in moist habitats to safeguard the overall forest diversity. Our findings further emphasize the need to consider soil moisture when planning the measures for riparian protection as changes in riparian soil moisture could lead to deterioration of organic matter decomposition. Different responses of the examined plant and microbial communities to riparian soil conditions clearly imply that overall riparian diversity cannot be explained based on a single community type, and that different organisms may respond differently to human-induced changes in stream riparian zone. Numéro de notice : A2022-485 Affiliation des auteurs : non IGN Thématique : BIODIVERSITE/FORET Nature : Article DOI : 10.1016/j.foreco.2022.120344 Date de publication en ligne : 04/06/2022 En ligne : https://doi.org/10.1016/j.foreco.2022.120344 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100923 [article]

GIS and machine learning for analysing influencing factors of bushfires using 40-year spatio-temporal bushfire data / Wanqin He in ISPRS International journal of geo-information, vol 11 n° 6 (June 2022)  

Public [article]  inISPRS International journal of geo-information > vol 11 n° 6 (June 2022) . - n° 336 Titre : GIS and machine learning for analysing influencing factors of bushfires using 40-year spatio-temporal bushfire data Type de document : Article/Communication Auteurs : Wanqin He, Auteur ; Sara Shirowzhan, Auteur ; Christopher Pettit, Auteur Année de publication : 2022 Article en page(s) : n° 336 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications SIG [Termes IGN] analyse diachronique [Termes IGN] apprentissage automatique [Termes IGN] brousse [Termes IGN] classification par forêts d'arbres décisionnels [Termes IGN] coefficient de corrélation [Termes IGN] données météorologiques [Termes IGN] données spatiotemporelles [Termes IGN] humidité du sol [Termes IGN] incendie [Termes IGN] indice de végétation [Termes IGN] Nouvelle-Galles du Sud [Termes IGN] prévention des risques [Termes IGN] régression linéaire [Termes IGN] Spark [Termes IGN] système d'information géographique [Termes IGN] température de l'air Résumé : (auteur) The causes of bushfires are extremely complex, and their scale of burning and probability of occurrence are influenced by the interaction of a variety of factors such as meteorological factors, topography, human activity and vegetation type. An in-depth understanding of the combined mechanisms of factors affecting the occurrence and spread of bushfires is needed to support the development of effective fire prevention plans and fire suppression measures and aid planning for geographic, ecological maintenance and urban emergency management. This study aimed to explore how bushfires, meteorological variability and other natural factors have interacted over the past 40 years in NSW Australia and how these influencing factors synergistically drive bushfires. The CSIRO’s Spark toolkit has been used to simulate bushfire burning spread over 24 h. The study uses NSW wildfire data from 1981–2020, combined with meteorological factors (temperature, precipitation, wind speed), vegetation data (NDVI data, vegetation type) and topography (slope, soil moisture) data to analyse the relationship between bushfires and influencing factors quantitatively. Machine learning-random forest regression was then used to determine the differences in the influence of bushfire factors on the incidence and burn scale of bushfires. Finally, the data on each influence factor was imported into Spark, and the results of the random forest model were used to set different influence weights in Spark to visualise the spread of bushfires burning over 24 h in four hotspot regions of bushfire in NSW. Wind speed, air temperature and soil moisture were found to have the most significant influence on the spread of bushfires, with the combined contribution of these three factors exceeding 60%, determining the spread of bushfires and the scale of burning. Precipitation and vegetation showed a greater influence on the annual frequency of bushfires. In addition, burn simulations show that wind direction influences the main direction of fire spread, whereas the shape of the flame front is mainly due to the influence of land classification. Besides, the simulation results from Spark could predict the temporal and spatial spread of fire, which is a potential decision aid for fireproofing agencies. The results of this study can inform how fire agencies can better understand fire occurrence mechanisms and use bushfire prediction and simulation techniques to support both their operational (short-term) and strategic (long-term) fire management responses and policies. Numéro de notice : A2022-481 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/ijgi11060336 Date de publication en ligne : 05/06/2022 En ligne : https://doi.org/10.3390/ijgi11060336 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100894 [article]

Forest floor alteration by canopy trees and soil wetness drive regeneration of a spruce-beech forest / Pavel Daněk in Forest ecology and management, vol 504 (15 January 2022)  

Public [article]  inForest ecology and management > vol 504 (15 January 2022) . - n° 119802 Titre : Forest floor alteration by canopy trees and soil wetness drive regeneration of a spruce-beech forest Type de document : Article/Communication Auteurs : Pavel Daněk, Auteur ; Pavel Šamonil, Auteur ; Libor Hort, Auteur Année de publication : 2022 Article en page(s) : n° 119802 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] bois mort [Termes IGN] canopée [Termes IGN] Fagus sylvatica [Termes IGN] humidité du sol [Termes IGN] litière [Termes IGN] peuplement mélangé [Termes IGN] Picea abies [Termes IGN] régénération (sylviculture) [Termes IGN] République Tchèque [Termes IGN] semis (sylviculture) [Termes IGN] sol forestier [Vedettes matières IGN] Foresterie Résumé : (auteur) Natural regeneration of European beech (Fagus sylvatica) and Norway spruce (Picea abies) plays a crucial role in the future of many European mountain forests. It is affected by various soil and stand-related factors whose relative importance, especially in mixed stands, is still not known. In this study, we assessed the importance of stand composition, soil wetness, disturbances and different microsites and seedbeds for regeneration of beech and spruce in a mixed old-growth mountain forest. We also focused on how the effects of these factors change as regeneration gets older. We sampled all regeneration in 563 plots from different microsite types (deadwood, intact soil, treethrow pits and mounds), distinguishing three seedbeds (mosses, beech litter, bare substrate) for seedlings. We used soil survey and tree census data with generalized linear mixed models and variance partitioning to identify the main factors driving tree regeneration and their relative importance. Although beech was slightly less abundant in the canopy than spruce, it strongly outnumbered spruce in regeneration. Beech regeneration showed an affinity for beech litter-rich microsites and drier soils, while spruce was more common on deadwood and moister soils and its response to the seedbed was microsite-specific. The regeneration of both species was positively related to the proportion of their own species in the canopy, but more so in seedlings than in older regeneration cohorts, where soil wetness was more important. The overall pattern of tree regeneration thus resulted from a complex interplay between site conditions and their alterations by current and former generations of canopy trees through the creation of new microsites (deadwood, uprooting mounds) or litter production. Where beech regeneration is not suppressed by excess soil wetness, it is much more successful than spruce due to its shade tolerance and ability to be established in the beech litter that dominates the forest floor. On the other hand, spruce regeneration is mostly restricted to elevated microsites with lower litter accumulation, such as deadwood and treethrow mounds. Our results indicate that both species exhibit an ability to modify their environment in favor of their own regeneration, but under current conditions, beech is more successful than spruce and can be expected to increase its dominance in the future. Numéro de notice : A2022-022 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1016/j.foreco.2021.119802 Date de publication en ligne : 04/11/2021 En ligne : https://doi.org/10.1016/j.foreco.2021.119802 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99214 [article]

Non-linear GNSS signal processing applied to land observation with high-rate airborne reflectometry / Hamza Issa (2022)  

Public Titre : Non-linear GNSS signal processing applied to land observation with high-rate airborne reflectometry Type de document : Thèse/HDR Auteurs : Hamza Issa, Auteur ; Serge Reboul, Directeur de thèse ; Ghaleb Faour, Directeur de thèse Editeur : Dunkerque : Université du Littoral-Côte-d'Opale Année de publication : 2022 Importance : 213 p. Format : 21 x 30 cm Note générale : Bibliographie Thèse en vue de l'obtention du grade de Docteur de l’Université du Littoral Côte d’Opale Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement du signal [Termes IGN] bande L [Termes IGN] données radar [Termes IGN] humidité du sol [Termes IGN] modèle statistique [Termes IGN] observation de la Terre [Termes IGN] précision métrique [Termes IGN] réflectométrie par GNSS [Termes IGN] signal GNSS [Termes IGN] zone humide Index. décimale : THESE Thèses et HDR Résumé : (Auteur) Soil moisture remote sensing has been an active area of research over the past few decades due to its essential role in agriculture and in the prediction of some natural disasters. GNSS-Reflectometry (GNSS-R) is an emerging bistatic remote sensing technique that uses the L-band GNSS signals as sources of opportunity to characterize Earth surface. In this passive radar system, the amplitudes of the GNSS signal reflected by soil and the GNSS signal received directly from the GNSS satellites can be used to derive measurements of reflectivity from which the soil moisture content of the surface is determined.The study of soil moisture content using reflectivity measurements can also be applied for the detection of in-land water body surfaces. In this dissertation, we propose in the first step a non-linear estimate of the GNSS signal amplitude. This estimate is based on a statistical model that we develop for the coherent detection of a GNSS signal quantized on 1 bit. We show with experimentations on synthetic and real data that the proposed estimator is more accurate than reference approaches and provide measurements of the Signal-to-Noise Ratio (SNR) at a higher rate. When the reflected GNSS signal is obtained in an airborne experiment, its evolution as a function of time is piecewise stationary. The different stationary parts are associatedto different kinds of reflecting surfaces. We propose in a second step a change point detector that takes into account the radar signal characteristics in order to segment the signal. We show on synthetic data that the proposed change point detector can detect and localize changes more accurately than reference approaches present in the literature. This work is applied to airborne GNSSR observation of Earth. We propose in the third step, a new GNSS-R sensor with its implementation on a lightweight airborne carrier. We also propose a new front-end receiver architecture, a software radio implementation of thereceiver, and the complete instrumentation of the airborne carrier. A real flight experimentation has taken place in the North of France obtaining reflections from different landforms. We show using the airborne GNSS measurements obtained, that the proposed radar technique detects different surfaces along the flight trajectory, and in particular in-land water bodies, with high temporal and spatial resolution. We also show that we can localize the edges of the detected water body surfaces at meter accuracy. Note de contenu : General Introduction 1. Remote Sensing of Soil Moisture 1.1 Introduction 1.2 L-band emissions of land covers 1.3 Soil moisture remote sensing techniques 1.4 Remote sensing using GNSS-R 1.5 Conclusion 2. Carrier-to-Noise Estimation : Application to Soil Moisture Retrieval using GNSS-R 2.1 Introduction 2.2 Signal and system model 2.3 C/N0 estimators 2.4 Soil moisture retrieval from GNSS-R 2.5 Conclusion 3. A Probabilistic Model for On-line Estimation of the GNSS Carrier?to-Noise Ratio 3.1 Introduction 3.2 1-bit coherent detection principle 3.3 GNSS front end 3.4 Estimation of the GNSS signal amplitude 3.5 Experimentation 3.6 Conclusion 4. Segmentation of the GNSS Signal Amplitudes 4.1 Introduction 4.2 Change point detection principle 4.3 On-line/Off-line change detection system 4.4 Experimentation 4.5 Conclusion 5. Airborne GNSS Reflectometry for Water Body Detection 5.1 Introduction 5.2 Airborne GNSS system 5.3 Airborne experimental setup 5.4 GNSS-R software receiver 5.5 Flight Experimentation 5.6 Data analysis 5.7 Conclusion General Conclusion Numéro de notice : 26837 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Thèse française Note de thèse : Thèse de Doctorat : Traitement du signal et des images : Université du Littoral Côte d’Opale : 2022 Organisme de stage : Laboratoire d'Informatique Signal et Image de la Côte d'Opale LISIC nature-HAL : Thèse DOI : sans Date de publication en ligne : 03/06/2022 En ligne : https://tel.archives-ouvertes.fr/tel-03687353/document Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101094

Python software to transform GPS SNR wave phases to volumetric water content / Angel Martín in GPS solutions, vol 26 n° 1 (January 2022)  

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Improving soil moisture retrieval from GNSS-interferometric reflectometry: parameters optimization and data fusion via neural network / Yajie Shi in International Journal of Remote Sensing IJRS, vol 42 n° 23 (1-10 December 2021)  

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Estimating regional soil moisture with synergistic use of AMSR2 and MODIS images / Majid Rahimzadegan in Photogrammetric Engineering & Remote Sensing, PERS, vol 87 n° 9 (September 2021)  

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Sentinel-1 sensitivity to soil moisture at high incidence angle and the impact on retrieval over seasonal crops / Davide Palmisano in IEEE Transactions on geoscience and remote sensing, Vol 59 n° 9 (September 2021)  

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Using electrical resistivity tomography to detect wetwood and estimate moisture content in silver fir (Abies alba Mill.) / Ludovic Martin in Annals of Forest Science [en ligne], vol 78 n° 3 (September 2021)  

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Random forests with bagging and genetic algorithms coupled with least trimmed squares regression for soil moisture deficit using SMOS satellite soil moisture / Pashrant K. Srivastava in ISPRS International journal of geo-information, vol 10 n° 8 (August 2021)  

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An integrated methodology for surface soil moisture estimating using remote sensing data approach / Rida Khellouk in Geocarto international, vol 36 n° 13 ([15/07/2021])  

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Characterization of mixed and monospecific stands of Scots pine and Maritime pine: soil profile, physiography, climate and vegetation cover data / Daphne Lopez-Marcos in Annals of Forest Science [en ligne], vol 78 n° 2 (June 2021)  

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A combined drought monitoring index based on multi-sensor remote sensing data and machine learning / Hongzhu Han in Geocarto international, vol 36 n° 10 ([01/06/2021])  

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Temporal mosaicking approaches of Sentinel-2 images for extending topsoil organic carbon content mapping in croplands / Emmanuelle Vaudour in International journal of applied Earth observation and geoinformation, vol 96 (April 2021)  

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