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Regeneration in European beech forests after drought: the effects of microclimate, deadwood and browsing / Dominik Thom in European Journal of Forest Research, vol 142 n° 2 (April 2023)
[article]
Titre : Regeneration in European beech forests after drought: the effects of microclimate, deadwood and browsing Type de document : Article/Communication Auteurs : Dominik Thom, Auteur ; Christian Ammer, Auteur ; Peter Annighöfer, Auteur ; et al., Auteur Année de publication : 2023 Article en page(s) : pp 259 - 27 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Allemagne
[Termes IGN] bois mort
[Termes IGN] Fagus sylvatica
[Termes IGN] rayonnement lumineux
[Termes IGN] régénération (sylviculture)
[Termes IGN] sécheresse
[Termes IGN] sous-étage
[Termes IGN] température de l'air
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) With progressing climate change, increasing weather extremes will endanger tree regeneration. Canopy openings provide light for tree establishment, but also reduce the microclimatic buffering effect of forests. Thus, disturbances can have both positive and negative impacts on tree regeneration. In 2015, three years before an extreme drought episode hit Central Europe, we established a manipulation experiment with a factorial block design in European beech (Fagus sylvatica L.)-dominated forests. At five sites located in southeastern Germany, we conducted three censuses of tree regeneration after implementing two different canopy disturbances (aggregated and distributed canopy openings), and four deadwood treatments (retaining downed, standing, downed + standing deadwood and removing all deadwood), as well as in one untreated control plot. In addition, we measured understory light levels and recorded local air temperature and humidity over five years. We (i) tested the effects of experimental disturbance and deadwood treatments on regeneration and (ii) identified the drivers of regeneration density as well as seedling species and structural diversity. Regeneration density increased over time. Aggregated canopy openings supported species and structural diversity, but reduced regeneration density. Tree regeneration was positively associated with understory light levels, while maximum vapor pressure deficit influenced tree regeneration negatively. Deadwood and browsing impacts on regeneration varied and were inconclusive. Our study indicates that despite the drought episode regeneration in beech-dominated forests persisted under moderately disturbed canopies. However, the positive effect of increased light availability on tree regeneration might have been offset by harsher microclimate after canopies have been disturbed. Numéro de notice : A2023-197 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1007/s10342-022-01520-1 Date de publication en ligne : 24/11/2022 En ligne : https://doi.org/10.1007/s10342-022-01520-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=103084
in European Journal of Forest Research > vol 142 n° 2 (April 2023) . - pp 259 - 27[article]Resource-based growth models reveal opportunities to mitigate climate change effects on beech regeneration by silvicultural measures / Jan F. Wilkens in Forest ecology and management, vol 532 (March-15 2023)
[article]
Titre : Resource-based growth models reveal opportunities to mitigate climate change effects on beech regeneration by silvicultural measures Type de document : Article/Communication Auteurs : Jan F. Wilkens, Auteur ; Robert Schlicht, Auteur ; Sven Wagner, Auteur Année de publication : 2023 Article en page(s) : n° 120815 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Europe (géographie politique)
[Termes IGN] Fagus sylvatica
[Termes IGN] gestion forestière
[Termes IGN] modèle de croissance végétale
[Termes IGN] rayonnement solaire
[Termes IGN] régénération (sylviculture)
[Termes IGN] semis (sylviculture)
[Termes IGN] sylviculture
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) Successful European beech (Fagus sylvatica L.) regeneration is both of great ecological and economical importance in European forest ecosystems and severely threatened by climate change impacts. To increase our knowledge of beech regeneration dynamics under climate change and the potential for controlling it through forest management, we studied interactive effects of solar radiation (PHAR), water and nutrient availability on the height growth of artificially (AR) and naturally regenerated (NR) beech seedlings. The study was conducted in the framework of experimental canopy gaps, under the influence of the 2018/19 drought and heatwaves. We measured PHAR by means of hemispherical photography, approximated water availability based on the inverse of modeled fine root density distributions of overstorey beech (BGRB) and oak (BGRO) and approximated nutrient availability based on soil fertility (SF), derived from forest site mapping. Results indicate that seedling resource availability and resulting growth responses increase with canopy gap size and vary among locations within the gap. Multiplicative non-linear mixed models suggest that AR and NR relative height growth (RI) was best explained by interactive effects of PHAR, BGRB, BGRO and SF, which reflect complementary resource use patterns of beech seedlings. At optimal resource availability, AR reached a potential RI of 174%, which is about 20% higher compared to NR. While the low light growth responses of AR and NR both reflect saturation at 5 to 15% PHAR, depending on individual size and the availability of the remaining resources, NR showed a higher RI than AR at intermediate and high PHAR levels in cases of limited BGR and SF. In contrast to AR, NR growth was affected to a lesser extent by SF and BGRB and not significantly affected by BGRO. These results suggest that overstorey oaks have a lower effect on water availability of beech seedlings than overstorey beeches. Additionally, NR showed higher tolerance to water and nutrient limitation than AR, probably due to better root system development. In conclusion, site-specific potential for mitigating the effects of climate change on beech regeneration through forest management lies in the adaptation of silvicultural systems, i.e., the creation of canopy gaps larger than 200 m2, thus significantly exceeding the average gap size of the natural disturbance regime, and the choice of the regeneration method. Numéro de notice : A2023-164 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1016/j.foreco.2023.120815 Date de publication en ligne : 26/01/2023 En ligne : https://doi.org/10.1016/j.foreco.2023.120815 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102869
in Forest ecology and management > vol 532 (March-15 2023) . - n° 120815[article]Multi-sensor airborne lidar requires intercalibration for consistent estimation of light attenuation and plant area density / Grégoire Vincent in Remote sensing of environment, vol 286 (March 2023)
[article]
Titre : Multi-sensor airborne lidar requires intercalibration for consistent estimation of light attenuation and plant area density Type de document : Article/Communication Auteurs : Grégoire Vincent, Auteur ; Philippe Verley, Auteur ; Benjamin Brede, Auteur ; et al., Auteur Année de publication : 2023 Article en page(s) : n° 113442 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] canopée
[Termes IGN] densité de la végétation
[Termes IGN] données lidar
[Termes IGN] forêt tropicale
[Termes IGN] Guyane (département français)
[Termes IGN] image captée par drone
[Termes IGN] plan de vol
[Termes IGN] rayonnement lumineux
[Termes IGN] réflectance végétale
[Termes IGN] semis de points
[Termes IGN] zone d'intérêtRésumé : (auteur) Leaf area is a key structural characteristic of forest canopies because of the role of leaves in controlling many biological and physical processes occurring at the biosphere-atmosphere transition. High pulse density Airborne Laser Scanning (ALS) holds promise to provide spatially resolved and accurate estimates of plant area density (PAD) in forested landscapes, a key step in understanding forest functioning: phenology, carbon uptake, transpiration, radiative balance etc. Inconsistencies between different ALS sensors is a barrier to generating globally harmonised PAD estimates. The basic assumption on which PAD estimation is based is that light attenuation is proportional to vegetation area density. This study shows that the recorded extinction strongly depends on target detectability which is influenced by laser characteristics (power, sensitivity, wavelength). Three different airborne laser scanners were flown over a wet tropical forest at the Paracou research station in French Guiana. Different sensors, flight heights and transmitted power levels were compared. Light attenuation was retrieved with an open source ray-tracing code (http://amapvox.org). Direct comparison revealed marked differences (up-to 25% difference in profile-averaged light attenuation rate and 50% difference at particular heights) that could only be explained by differences in scanner characteristics. We show how bias which may occur under various acquisition conditions can generally be mitigated by a sensor intercalibration. Alignment of light weight lidar attenuation profiles to ALS reference attenuation profiles is not always satisfactory and we discuss what are the likely sources of discrepancies. Neglecting the dependency of apparent light attenuation on scanner properties may lead to biases in estimated vegetation density commensurate to those affecting light attenuation estimates. Applying intercalibration procedures supports estimation of plant area density independent of acquisition characteristics. Numéro de notice : A2023-169 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.1016/j.rse.2022.113442 Date de publication en ligne : 06/01/2023 En ligne : https://doi.org/10.1016/j.rse.2022.113442 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102928
in Remote sensing of environment > vol 286 (March 2023) . - n° 113442[article]Point cloud data processing optimization in spectral and spatial dimensions based on multispectral Lidar for urban single-wood extraction / Shuo Shi in ISPRS International journal of geo-information, vol 12 n° 3 (March 2023)
[article]
Titre : Point cloud data processing optimization in spectral and spatial dimensions based on multispectral Lidar for urban single-wood extraction Type de document : Article/Communication Auteurs : Shuo Shi, Auteur ; Xingtao Tang, Auteur ; Bowen Chen, Auteur ; et al., Auteur Année de publication : 2023 Article en page(s) : n° 90 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] analyse spectrale
[Termes IGN] arbre urbain
[Termes IGN] détection d'objet
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] Houston (Texas)
[Termes IGN] interpolation
[Termes IGN] réflectance spectrale
[Termes IGN] segmentation
[Termes IGN] semis de pointsRésumé : (auteur) Lidar can effectively obtain three-dimensional information on ground objects. In recent years, lidar has developed rapidly from single-wavelength to multispectral hyperspectral imaging. The multispectral airborne lidar Optech Titan is the first commercial system that can collect point cloud data on 1550, 1064, and 532 nm channels. This study proposes a method of point cloud segmentation in the preprocessed intensity interpolation process to solve the problem of inaccurate intensity at the boundary during point cloud interpolation. The entire experiment consists of three steps. First, a multispectral lidar point cloud is obtained using point cloud segmentation and intensity interpolation; the spatial dimension advantage of the multispectral point cloud is used to improve the accuracy of spectral information interpolation. Second, point clouds are divided into eight categories by constructing geometric information, spectral reflectance information, and spectral characteristics. Accuracy evaluation and contribution analysis are also conducted through point cloud truth value and classification results. Lastly, the spatial dimension information is enhanced by point cloud drop sampling, the method is used to solve the error caused by airborne scanning and single-tree extraction of urban trees. Classification results showed that point cloud segmentation before intensity interpolation can effectively improve the interpolation and classification accuracies. The total classification accuracy of the data is improved by 3.7%. Compared with the extraction result (377) of single wood without subsampling treatment, the result of the urban tree extraction proved the effectiveness of the proposed method with a subsampling algorithm in improving the accuracy. Accordingly, the problem of over-segmentation is solved, and the final single-wood extraction result (329) is markedly consistent with the real situation of the region. Numéro de notice : A2023-159 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/ijgi12030090 Date de publication en ligne : 23/02/2023 En ligne : https://doi.org/10.3390/ijgi12030090 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102852
in ISPRS International journal of geo-information > vol 12 n° 3 (March 2023) . - n° 90[article]Resilience of Pyrenean forests after recurrent historical deforestations / Valenti Rull in Forests, vol 14 n° 3 (March 2023)
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Titre : Resilience of Pyrenean forests after recurrent historical deforestations Type de document : Article/Communication Auteurs : Valenti Rull, Auteur ; Teresa Vegas-Vilarrúbia, Auteur Année de publication : 2023 Article en page(s) : n° 567 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] déboisement
[Termes IGN] forêt méditerranéenne
[Termes IGN] histoire
[Termes IGN] historique des données
[Termes IGN] régénération (sylviculture)
[Termes IGN] résilience écologique
[Vedettes matières IGN] Ecologie forestièreRésumé : (auteur) The long-term resilience of Pyrenean forests in the face of historical anthropogenic clearing remains largely unknown. In this paper, a high-resolution (decadal to subdecadal) paleoecological study of mid-elevation Pyrenean forests is presented that encompasses the last two millennia. This long-term record was obtained after sediment coring, dating (varve counting) and pollen analysis of annually laminated (varved) sediments from Lake Montcortès, situated at 1027 m elevation, in the transition between the Mediterranean and montane forest belts. This allowed the definition of three major deforestation/recovery cycles during the Roman, Medieval and Modern times. Each DR cycle is characterized considering three different levels: overall forest trends, forest type and individual taxa. Overall, the studied forests exhibited high resilience, as they recovered almost completely after each deforestation event (bulk resilience). The critical point of no return (tipping point) beyond which forests would have irreversibly disappeared from the region was never reached, even after deforestation magnitudes above 60%. The different forest types identified (conifer, sclerophyll and deciduous) persisted over time, showing similar heterogeneous patterns with minor spatial reorganizations (mosaic resilience). Individually, the main forest taxa underwent minor variations in their relative abundances, always within the same attraction domains (community resilience). The high levels of resilience documented in these Pyrenean forests are attributed to the action of metapopulation and metacommunity processes and mechanisms in a highly dynamic patchy environment. Conservation actions should be focused on the maintenance of these spatial patterns and the associated ecological dynamics. Numéro de notice : A2023-166 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.3390/f14030567 Date de publication en ligne : 13/03/2023 En ligne : https://doi.org/10.3390/f14030567 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102903
in Forests > vol 14 n° 3 (March 2023) . - n° 567[article]Species distribution modelling under climate change scenarios for maritime pine (Pinus pinaster Aiton) in Portugal / Cristina Alegria in Forests, vol 14 n° 3 (March 2023)PermalinkUne sylviculture dynamique des chênaies sessiliflores favorise la résilience des arbres après une forte sécheresse / Anna Schmitt in Revue forestière française, vol 74 n° 1 (2023)PermalinkThe potential of combining satellite and airborne remote sensing data for habitat classification and monitoring in forest landscapes / Anna Iglseder in International journal of applied Earth observation and geoinformation, vol 117 (March 2023)PermalinkTree species growth response to climate in mixtures of Quercus robur/Quercus petraea and Pinus sylvestris across Europe - a dynamic, sensitive equilibrium / Sonja Vospernik in Forest ecology and management, vol 530 (February-15 2023)PermalinkCan mixed forests sequester more CO2 than pure forests in future climate scenarios? A case study of Pinus sylvestris combinations in Spain / Diego Rodríguez de Prado in European Journal of Forest Research, vol 142 n° 1 (February 2023)PermalinkEvaluation of growth models for mixed forests used in Swedish and Finnish decision support systems / Jorge Aldea in Forest ecology and management, vol 529 (February-1 2023)PermalinkForest structure and fine root biomass influence soil CO2 efflux in temperate forests under drought / Antonios Apostolakis in Forests, vol 14 n° 2 (February 2023)PermalinkNonparametric upscaling of bark beetle infestations and management from plot to landscape level by combining individual-based with Markov chain models / Bruno Walter Pietzsch in European Journal of Forest Research, vol 142 n° 1 (February 2023)PermalinkSpecies-specific deadwood density, its controlling factors and its role in the estimation of deadwood C stock of a Virgin European Beech-Silver Fir Mixed Forest in the Southern Carpathians / Ion Catalin Petritan in SSRN [preprint electronic journal], vol 2023 ([01/02/2023])PermalinkStochastic multicriteria acceptability analysis as a forest management priority mapping approach based on airborne laser scanning and field inventory data / Parvez Rana in Landscape and Urban Planning, vol 230 (February 2023)Permalink