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Auteur Christian Piedallu
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LERFOB – AgroParisTech-ENGREF - Nancy.
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Affiner la recherche Interroger des sources externesClimate and ungulate browsing impair regeneration dynamics in spruce-fir-beech forests in the French Alps / Mithila Unkule in Annals of Forest Science, vol 79 n° 1 (2022)
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 climatiqueRésumé : (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
in Annals of Forest Science > vol 79 n° 1 (2022) . - n° 11[article]
Titre : Climate change-induced background tree mortality is exacerbated towards the warm limits of the species ranges Type de document : Article/Communication Auteurs : Adrien Taccoen, Auteur ; Christian Piedallu, Auteur ; Ingrid Seynave, Auteur ; Anne Gégout-Petit, Auteur ; Jean-Claude Gégout, Auteur Année de publication : 2022 Article en page(s) : n° 23 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] arbre mort
[Termes IGN] changement climatique
[Termes IGN] espèce végétale
[Termes IGN] inventaire forestier national (données France)
[Termes IGN] mortalité
[Termes IGN] stress hydrique
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) Key message : An influence of the recent changes in temperature or rainfall was demonstrated, increasing background tree mortality rates for 2/3 of the 12 studied tree species. Climate change-induced tree mortality was exacerbated towards the warm or dry limits of the species ranges, suggesting in these areas a progressive replacement by more xeric species.
Context : Despite the identification of climate change effects on tree mortality in various biomes, the characterization of species-specific areas of vulnerability remains poorly understood.
Aims : We sought to assess if the effects of temperature and rainfall changes on background tree mortality rates, which did not result from abrupt disturbances, were linked to climate change intensity only, or if they also depended on the tree’s location along climatic gradients.
Methods : We modelled background mortality for 12 of the most common European tree species using 265,056 trees including 4384 dead trees from the French national forest inventory. To explain mortality, we considered variables linked to tree characteristics, stand attributes, logging intensity and site environmental characteristics, and climate change effects.
Results : We found an influence of temperature and rainfall changes on 9 species out of 12. For 8 of them, climate change-induced tree mortality was exacerbated towards the warm or dry limits of the species ranges.
Conclusion : These results highlight that tree mortality varies according to the climate change intensity and the tree location along temperature and rainfall gradients. They strengthen the poleward and upward shifts of trees forecasted from climate envelope models for a large number of European tree species.Numéro de notice : A2022-440 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1186/s13595-022-01142-y Date de publication en ligne : 30/05/2022 En ligne : http://dx.doi.org/10.1186/s13595-022-01142-y Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100773
in Annals of Forest Science > vol 79 n° 1 (2022) . - n° 23[article]
Titre : Multisource forest inventories: A model-based approach using k-NN to reconcile forest attributes statistics and map products Type de document : Article/Communication Auteurs : Ankit Sagar Année de publication : 2022 Projets : LUE / Université de Lorraine, ARBRE / AgroParisTech (2007 -), DEEPSURF / Pironon, Jacques Article en page(s) : pp 175 - 188 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] classification barycentrique
[Termes IGN] données allométriques
[Termes IGN] données lidar
[Termes IGN] image Landsat-8
[Termes IGN] inventaire forestier national (données France)
[Vedettes matières IGN] Inventaire forestierRésumé : (auteur) Forest map products are widely used and have taken benefit from progresses in the multisource forest inventory approaches, which are meant to improve the precision of forest inventory estimates at high spatial resolution. However, estimating errors of pixel-wise predictions remains difficult, and reconciling statistical outcomes with map products is still an open and important question. We address this problem using an original approach relying on a model-based inference framework and k-nearest neighbours (k-NN) models to produce pixel-wise estimations and related quality assessment. Our approach takes advantage of the resampling properties of a model-based estimator and combines it with geometrical convex-hull models to measure respectively the precision and accuracy of pixel predictions. A measure of pixel reliability was obtained by combining precision and accuracy. The study was carried out over a 7,694 km2 area dominated by structurally complex broadleaved forests in centre of France. The targeted forest attributes were growing stock volume, basal area and growing stock volume increment. A total of 819 national forest inventory plots were combined with auxiliary data extracted from a forest map, Landsat 8 images, and 3D point clouds from both airborne laser scanning and digital aerial photogrammetry. k-NN models were built independently for both 3D data sources. Both selected models included 5 auxiliary variables, and were generated using 5 neighbours, and most similar neighbours distance measure. The models showed relative root mean square error ranging from 35.7% (basal area, digital aerial photogrammetry) in calibration to 63.4% (growing stock volume increment, airborne laser scanning) in the validation set. At pixel level, we found that a minimum of 86.4% of the predictions were of high precision as their bootstrapped coefficient of variation fall below calibration’s relative root mean square error. The amount of extrapolation varied from 4.3% (digital aerial photogrammetry) to 6.3% (airborne laser scanning). A relationship was found between extrapolation and k-NN distance, opening new opportunities to correct extrapolation errors. At the population level, airborne laser scanning and digital aerial photogrammetry performed similarly, offering the possibility to use digital aerial photogrammetry for monitoring purposes. The proposed method provided consistent estimates of forest attributes and maps, and also provided spatially explicit information about pixel predictions in terms of precision, accuracy and reliability. The method therefore produced high resolution outputs, significant for either decision making or forest management purposes. Numéro de notice : A2022-629 Affiliation des auteurs : LIF+Ext (2020- ) Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2022.08.016 En ligne : https://doi.org/10.1016/j.isprsjprs.2022.08.016 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101495
in ISPRS Journal of photogrammetry and remote sensing > vol 192 (October 2022) . - pp 175 - 188[article]
Titre : Optimal resolution of soil properties maps varies according to their geographical extent and location Type de document : Article/Communication Auteurs : Christian Piedallu, Auteur ; Eloïse Pedersoli, Auteur ; Emeline Chaste, Auteur ; François Morneau Année de publication : 2022 Projets : 3-projet - voir note / Pironon, Jacques Article en page(s) : n° 115723 Note générale : bibliographie
This study was funded through the Rescale project by the Regional Council of Grand-Est (“Region Grand-Est”) and the “Direction de l’Agriculture et de la Forêt (DRAF) “Grand-Est.Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Cartographie thématique
[Termes IGN] azote
[Termes IGN] carbone
[Termes IGN] carte pédologique
[Termes IGN] échelle cartographique
[Termes IGN] Grand Est (région 2016)
[Termes IGN] inventaire forestier national (données France)
[Termes IGN] pédologie locale
[Termes IGN] potentiel hydrogène
[Termes IGN] précision cartographiqueRésumé : (auteur) The important development of digital soil mapping (DSM) these last decades has led to a large number of maps of soil properties with increasingly finer raster size. Map resolution is mostly determined by expert knowledge or by matching with the resolution of existing data, while scale is recognized as a major issue. Using the pH and the C/N ratio describing the surface horizon of forest soils and estimated by bioindication, we evaluated the effect of resolution changes on model and map performance for different geographical extents. Using 40,663 plots from the national forest inventory and 25 environmental variables calculated at eight different spatial resolution levels (50, 100, 250, 500, 1000, 8000, 16,000, and 50,000 m), we modeled and mapped pH and C/N over a vast and diversified area of 91,000 km2 in the north-east of France. The models highlighted the importance of geology in pH and C/N spatial variations, and to a lesser extent the importance of stand type, climate and topography, with a slight influence of data resolution on predictor selection. On the contrary, the accuracy of model or map performance decreased significantly above 1000 m resolution. Significant performance differences were observed according to the location and the size of the geographical extent. Globally, the more heterogeneous environmental characteristics and the smaller the geographical extent, the better fine spatial resolution performed. In addition, the aggregation of fine-resolution pH or C/N maps at a coarser cell size improved map performance as compared to the direct use of the coarse-resolution predictors. The impact of resolution changes on map accuracy varies according to the mapping procedure, the local environment, and the geographical extent, and should be evaluated in DSM studies to optimize map accuracy. Numéro de notice : A2022-141 Affiliation des auteurs : IGN+Ext (2020- ) Autre URL associée : vers HAL Thématique : FORET/GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.geoderma.2022.115723 Date de publication en ligne : 01/02/2022 En ligne : https://doi.org/10.1016/j.geoderma.2022.115723 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99953
in Geoderma > vol 412 (15 April 2022) . - n° 115723[article]
Titre : Assessment of habitat vulnerability for a better adaptation of forests to climate change Type de document : Article/Communication Auteurs : Ceridwen Dupont-Doaré, Auteur ; Thomas Brusten, Auteur ; Christian Piedallu, Auteur ; Ingrid Bonhême Editeur : Nancy, Metz : Université de Lorraine Année de publication : 2022 Conférence : SFE² GfÖ EEF 2022, joint meeting, international conference on ecological sciences, Ecology and evolution: new perspectives and societal challenges 21/11/2022 25/11/2022 Metz France OA Abstracts only Langues : Anglais (eng) Résumé : (auteur) Effects of climate change over temperate forest ecosystems are increasingly visible. Most of the tools developed to evaluate the risks associated to climate change mainly focus on individual tree species (phenology, productivity, overmortality, distribution, etc.), without an integrative outlook of ecosystems’ vulnerability. To meet the urgent need of adaptation, it is imperative to determine the climatic vulnerability of forest habitats in order to better support them in current upheavals. We put forward a methodology to evaluate forest habitats vulnerability to climate change that can be used either for a territorial or for a stand scale of study. It is based on an index approach, with indexes related to the different components of vulnerability -exposure, sensitivity and adaptive capacity-. Exposure indexes study how the climate evolves inside the habitat’s range of distribution, and how the habitat is exposed to pests or pathogenic fungi for its main tree species. Sensitivity indexes include habitat, tree and floristic species distribution modelling and projection under several scenarios of climate change. Sensitivity also relies on dieback measurements. Finally, adaptive capacity considers information about i) the potential extension of the habitat’s distribution range, ii) habitat successional stage, iii) traits of the main tree species composing the habitat, field data related to iv) stand structural diversity, v) tree species richness, vi) historical and geographical context. Once the indexes are determined, they are combined to characterise the vulnerability status of the habitat. According to the estimated level of vulnerability, management recommendations falling within the concept of adaptive silviculture are suggested in order to anticipate and mitigate the effects of climate change. Management recommendations draw on experiments and practices already implemented in the study area, as well as discussion with local stakeholders, so that they best respond to the issues of the territory. In addition, test parcels can be set-up to try adaptive silviculture techniques based on scientific literature. Numéro de notice : C2022-046 Affiliation des auteurs : IGN+Ext (2020- ) Thématique : FORET Nature : Poster nature-HAL : Poster-avec-CL DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102435 Documents numériques
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