Détail de l'auteur
Auteur Georg von Arx |
Documents disponibles écrits par cet auteur (3)
Ajouter le résultat dans votre panier Affiner la recherche Interroger des sources externesXylem anatomy of Robinia pseudoacacia L. and Quercus robur L. is differently affected by climate in a temperate alluvial forest / Paola Nola in Annals of Forest Science, Vol 77 n° 1 (March 2020)
Titre : Xylem anatomy of Robinia pseudoacacia L. and Quercus robur L. is differently affected by climate in a temperate alluvial forest Type de document : Article/Communication Auteurs : Paola Nola, Auteur ; Francesco Bracco, Auteur ; Silvia Assini, Auteur ; Georg von Arx, Auteur ; Daniele Catagneri, Auteur Année de publication : 2020 Article en page(s) : 16 p. Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] cerne
[Termes IGN] dendrochronologie
[Termes IGN] espèce exotique envahissante
[Termes IGN] espèce pionnière
[Termes IGN] forêt ripicole
[Termes IGN] gestion forestière
[Termes IGN] orthoptère
[Termes IGN] Quercus pedunculata
[Termes IGN] Robinia pseudoacacia
[Termes IGN] sécheresse
[Termes IGN] variation saisonnière
[Termes IGN] xylème
[Termes IGN] zone tempérée
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) Key message: Xylem hydraulic traits of native Quercus robur are more sensitive to previous-summer drought than those of alien Robinia pseudoacacia. The latter modulates vessel traits and ring porosity to cope with inter-annual climate variability, and is less affected by extreme events. This suggests that R. pseudoacacia might be more competitive under future drier conditions. Context: Forest management strategies require knowledge on how co-occurring native and alien species respond to unprecedented climate conditions, which can severely affect xylem conductivity and tree performance. Aims: We aimed at quantitatively comparing xylem anatomical traits of co-occurring native Quercus robur and alien Robinia pseudoacacia and assessing similarities and differences in their response to climate variability. Methods: We analyzed tree-ring anatomy and built chronologies of several parameters related to vessel number, size, and theoretical conductivity. Mean chronologies for each parameter were correlated to monthly temperature and precipitation data for the period 1954–2005 and within 30-year moving windows. We also assessed responses to extreme conditions in 2003. Results: Quercus robur showed typical ring-porous vessel distribution, while R. pseudoacacia modulated vessel size and number year by year, frequently showing semi-ring porous appearance. Previous rainy summers increased size of large vessels in Q. robur, and number of large vessels in R. pseudoacacia. In winter, R. pseudoacacia was sensitive to water excess. High temperature in March increased vessel size in Q. robur, but reduced it in R. pseudoacacia. The 2003 summer heatwave strongly reduced vessel size and number in the following year in Q. robur, but had much less effect on R. pseudoacacia. Conclusion: Quercus robur xylem traits are more influenced by both inter-annual climate variability and extreme events than those of R. pseudoacacia. Lower performance under dry conditions might reduce competitiveness of Q. robur in the future, slowing down the natural replacement of the invasive pioneer R. pseudoacacia by later-stage Q. robur. Numéro de notice : A2020-068 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s13595-019-0906-z Date de publication en ligne : 10/01/2020 En ligne : https://doi.org/10.1007/s13595-019-0906-z Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94581
in Annals of Forest Science > Vol 77 n° 1 (March 2020) . - 16 p.[article]
Titre : Couplings in cell differentiation kinetics mitigate air temperature influence on conifer wood anatomy Type de document : Article/Communication Auteurs : Henri E. Cuny Année de publication : 2019 Projets : 3-projet - voir note / Article en page(s) : pp 1222 - 1232 Note générale : bibliographie
The authors acknowledge the Swiss National Science Foundation SNF (projects CLIMWOOD‐160077 and LOTFOR‐150205). G. v. A. was supported by a grant from the Swiss State Secretariat for Education, Research and Innovation SERI (SBFI C14.0104). This research also benefited from the support of the FPS COST Action STReESS (FP1106).Langues : Anglais (eng) Descripteur : [Termes IGN] anatomie du bois
[Termes IGN] cerne
[Termes IGN] Europe centrale
[Termes IGN] Larix decidua
[Termes IGN] Picea abies
[Termes IGN] Pinophyta
[Termes IGN] température de l'air
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) Conifer trees possess a typical anatomical tree‐ring structure characterized by a transition from large and thin‐walled earlywood tracheids to narrow and thick‐walled latewood tracheids. However, little is known on how this characteristic structure is maintained across contrasting environmental conditions, due to its crucial role to ensure sap ascent and mechanical support. In this study, we monitored weekly wood cell formation for up to 7 years in two temperate conifer species (i.e., Picea abies (L.) Karst and Larix decidua Mill.) across an 8°C thermal gradient from 800 to 2,200 m a.s.l. in central Europe to investigate the impact of air temperature on rate and duration of wood cell formation. Results indicated that towards colder sites, forming tracheids compensate a decreased rate of differentiation (cell enlarging and wall thickening) by an extended duration, except for the last cells of the latewood in the wall‐thickening phase. This compensation allows conifer trees to mitigate the influence of air temperature on the final tree‐ring structure, with important implications for the functioning and resilience of the xylem to varying environmental conditions. The disappearing compensation in the thickening latewood cells might also explain the higher climatic sensitivity usually found in maximum latewood density. Numéro de notice : A2019-272 Affiliation des auteurs : IGN+Ext (2012-2019) Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/pce.13464 Date de publication en ligne : 16/10/2018 En ligne : https://doi.org/10.1111/pce.13464 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95323
in Plant, cell & environment > vol 42 n° 4 (April 2019) . - pp 1222 - 1232[article]
Titre : RAPTOR: Row and position tracheid organizer in R [technical note] Type de document : Article/Communication Auteurs : Richard L. Peters, Auteur ; Daniel Balanzategui, Auteur ; Alexander G. Hurley, Auteur ; Georg von Arx, Auteur ; Angela Luisa Prendin, Auteur ; Henri E. Cuny Année de publication : 2018 Projets : 3-projet - voir note / Article en page(s) : pp 10 - 16 Note générale : bbliographie
This work was funded by the Swiss National Science Foundation (Project LOTFOR no. 150205). DB used infra-structure of the Terrestrial Environmental Observatory (TERENO) of the Helmholtz Association and was supported by the Deutsche Forschungsgemeinschaft, DFG, project number HE 7220/1-1.Langues : Anglais (eng) Descripteur : [Termes IGN] fonctionnalité
[Termes IGN] R (langage)Résumé : (auteur) Mechanistic understanding of tree-ring formation and its modelling requires a cellular-based and spatially organized characterization of a tree ring, moving from whole rings, to intra-annual growth zones and individual cells. A tracheidogram is a radial profile of conifer anatomical features, such as lumen area and cell wall thickness, of sequentially- and positionally-ranked tracheids. However, its construction is tedious and time-consuming since image-analysis-based measurements do not recognize the position of cells within a radial file, and present-day tracheidograms must be constructed manually.
Here we present the R-package RAPTOR that complements tracheid anatomical data obtained from quantitative wood anatomy software (e.g., ROXAS, WinCELL, ImageJ), with the specific positional information necessary for the automated construction of tracheidograms. The package includes functions to read and visualize tracheid anatomical data, and uses local search algorithms to ascribe a ranked position to each tracheid in identified radial files. The package also provides functions to ensure that tracheids are adequately aligned for identifying the first tracheid in each radial file, and obtaining the correct ranking of tracheids along each radial file. Additional functions allow automating the analyses for multiple samples and rings (batch mode) and exporting data and plots for quality control.
RAPTOR allows tracheidogram users to take advantage of the latest generation of cell anatomical measuring systems. With this R-package we aim to facilitate the construction of more robust and versatile tracheidograms for the benefit of the research community.Numéro de notice : A2018-666 Affiliation des auteurs : IGN+Ext (2012-2019) Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.dendro.2017.10.003 Date de publication en ligne : 15/11/2017 En ligne : https://doi.org/10.1016/j.dendro.2017.10.003 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94257
in Dendrochronologia > vol 47 (February 2018) . - pp 10 - 16[article]
