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Chouteau S, Stafford L, Granier A, Goullet A, Richard-Plouet M. Handling Nanoparticle Content in Nanocomposite Thin Films Deposited by Misty Plasma Processes through Controlled Flash Boiling Atomization. Langmuir 2024. [PMID: 38310517 DOI: 10.1021/acs.langmuir.3c03176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2024]
Abstract
Misty plasma processes based on colloidal solutions sprayed into low-pressure plasmas have recently shown great potential for multifunctional thin film deposition. In such processes, nanoparticle accumulation in ring-shaped structures remains the main obstacle to the synthesis of high-quality coatings containing abundant, small-scale, and evenly dispersed nanoparticles. These local buildups appear after a colloidal droplet evaporates from a substrate. Accordingly, controlling the droplets' size in the spray is of key importance to ensure a uniform nanoparticle content in the plasma-deposited nanocomposite film. In this work, it is shown that the use of more volatile solvents produces finer droplets on the substrate, thereby improving nanoparticle dispersion in the matrix. A one-dimensional evaporation model is further developed and used to show that, contrary to what one might expect, this result cannot be attributed to faster evaporation during droplet transport in the low-pressure plasma. Instead, a so-called "flash" boiling atomization mechanism is discussed to support the experimental findings.
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Affiliation(s)
- S Chouteau
- Nantes Université, CNRS, Institut des Matériaux de Nantes Jean Rouxel, IMN, F-44000 Nantes, France
- Département de physique, Université de Montréal, 1375 Ave. Thérèse-Lavoie-Roux, Montréal, Québec H2V 0B3, Canada
| | - L Stafford
- Département de physique, Université de Montréal, 1375 Ave. Thérèse-Lavoie-Roux, Montréal, Québec H2V 0B3, Canada
| | - A Granier
- Nantes Université, CNRS, Institut des Matériaux de Nantes Jean Rouxel, IMN, F-44000 Nantes, France
| | - A Goullet
- Nantes Université, CNRS, Institut des Matériaux de Nantes Jean Rouxel, IMN, F-44000 Nantes, France
| | - M Richard-Plouet
- Nantes Université, CNRS, Institut des Matériaux de Nantes Jean Rouxel, IMN, F-44000 Nantes, France
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Dey B, Bulou S, Gaulain T, Ravisy W, Richard-Plouet M, Goullet A, Granier A, Choquet P. Anatase TiO 2 deposited at low temperature by pulsing an electron cyclotron wave resonance plasma source. Sci Rep 2020; 10:21952. [PMID: 33319806 PMCID: PMC7738520 DOI: 10.1038/s41598-020-78956-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Accepted: 11/27/2020] [Indexed: 01/26/2023] Open
Abstract
Photocatalytic surfaces have the potentiality to respond to many of nowadays societal concerns such as clean H2 generation, CO2 conversion, organic pollutant removal or virus inactivation. Despite its numerous superior properties, the wide development of TiO2 photocatalytic surfaces suffers from important drawbacks. Hence, the high temperature usually required (> 450 °C) for the synthesis of anatase TiO2 is still a challenge to outreach. In this article, we report the development and optimisation of an ECWR-PECVD process enabling the deposition of anatase TiO2 thin films at low substrate temperature. Scanning of experimental parameters such as RF power and deposition time was achieved in order to maximise photocatalytic activity. The careful selection of the deposition parameters (RF power, deposition time and plasma gas composition) enabled the synthesis of coatings exhibiting photocatalytic activity comparable to industrial references such as P25 Degussa and Pilkington Activ at a substrate temperature below 200 °C. In addition, to further decrease the substrate temperature, the interest of pulsing the plasma RF source was investigated. Using a duty cycle of 50%, it is thus possible to synthesise photocatalytic anatase TiO2 thin films at a substrate temperature below 115 °C with a deposition rate around 10 nm/min.
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Affiliation(s)
- B Dey
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology, 5 Avenue des Hauts-Fourneaux, 4362, Esch-sur-Alzette, Luxembourg
| | - S Bulou
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology, 5 Avenue des Hauts-Fourneaux, 4362, Esch-sur-Alzette, Luxembourg.
| | - T Gaulain
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology, 5 Avenue des Hauts-Fourneaux, 4362, Esch-sur-Alzette, Luxembourg
| | - W Ravisy
- Institut Des Matériaux Jean Rouxel (IMN), Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229 44322, Nantes, France
| | - M Richard-Plouet
- Institut Des Matériaux Jean Rouxel (IMN), Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229 44322, Nantes, France
| | - A Goullet
- Institut Des Matériaux Jean Rouxel (IMN), Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229 44322, Nantes, France
| | - A Granier
- Institut Des Matériaux Jean Rouxel (IMN), Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229 44322, Nantes, France
| | - P Choquet
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology, 5 Avenue des Hauts-Fourneaux, 4362, Esch-sur-Alzette, Luxembourg
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3
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Forner A, Valladares F, Bonal D, Granier A, Grossiord C, Aranda I. Extreme droughts affecting Mediterranean tree species' growth and water-use efficiency: the importance of timing. Tree Physiol 2018; 38:1127-1137. [PMID: 29554342 DOI: 10.1093/treephys/tpy022] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Accepted: 02/09/2018] [Indexed: 06/08/2023]
Abstract
It has been known for a long time that drought intensity is a critical variable in determining water stress of Mediterranean tree species. However, not as much attention has been paid to other drought characteristics, for example the timing of the dry periods. We investigated the impact of the timing and intensity of extreme droughts on growing season length, growth and water-use efficiency of three tree species, Pinus nigra ssp. Salzmannii J.F. Arnold, Quercus ilex ssp. ballota (Desf.) Samp. and Quercus faginea Lam. coexisting in a continental Mediterranean ecosystem. Over the study period (2009-13), intense droughts were observed at annual and seasonal scales, particularly during 2011 and 2012. In 2012, an atypically dry winter and spring was followed by an intense summer drought. Quercus faginea growth was affected more by drought timing than by drought intensity, probably because of its winter-deciduous leaf habit. Pinus nigra showed a lower decrease in secondary growth than observed in the two Quercus species in extremely dry years. Resilience to extreme droughts was different among species, with Q. faginea showing poorer recovery of growth after very dry years. The highest intra- and inter-annual plasticity in water-use efficiency was observed in P. nigra, which maintained a more water-saving strategy. Our results revealed that the timing of extreme drought events can affect tree function to a larger extent than drought intensity, especially in deciduous species. Legacy effects of drought over months and years significantly strengthened the impact of drought timing and intensity on tree function.
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Affiliation(s)
- Alicia Forner
- Laboratorio Internacional de Cambio Global (LINCGlobal), Departamento de Biogeografía y Cambio Global, Museo Nacional de Ciencias Naturales, MNCN, CSIC, Serrano 115 dpdo, Madrid, Spain
| | - Fernando Valladares
- Laboratorio Internacional de Cambio Global (LINCGlobal), Departamento de Biogeografía y Cambio Global, Museo Nacional de Ciencias Naturales, MNCN, CSIC, Serrano 115 dpdo, Madrid, Spain
- Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnológicas, Universidad Rey Juan Carlos, c/ Tulipán s/n, Móstoles, Spain
| | - Damien Bonal
- INRA, Université de Lorraine, UMR 1137 Ecologie et Ecophysiologie Forestières, Champenoux, France
| | - André Granier
- INRA, Université de Lorraine, UMR 1137 Ecologie et Ecophysiologie Forestières, Champenoux, France
| | - Charlotte Grossiord
- Earth and Environmental Sciences, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Ismael Aranda
- Department of Forest Ecology and Genetics, INIA, Forest Research Centre, Avda. A Coruña km 7.5, Madrid, Spain
- INAGEA, Instituto de Investigaciones Agroambientales y de Economía del Agua, Palma de Mallorca, Islas Baleares, Spain
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4
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van der Plas F, Ratcliffe S, Ruiz-Benito P, Scherer-Lorenzen M, Verheyen K, Wirth C, Zavala MA, Ampoorter E, Baeten L, Barbaro L, Bastias CC, Bauhus J, Benavides R, Benneter A, Bonal D, Bouriaud O, Bruelheide H, Bussotti F, Carnol M, Castagneyrol B, Charbonnier Y, Cornelissen JHC, Dahlgren J, Checko E, Coppi A, Dawud SM, Deconchat M, De Smedt P, De Wandeler H, Domisch T, Finér L, Fotelli M, Gessler A, Granier A, Grossiord C, Guyot V, Haase J, Hättenschwiler S, Jactel H, Jaroszewicz B, Joly FX, Jucker T, Kambach S, Kaendler G, Kattge J, Koricheva J, Kunstler G, Lehtonen A, Liebergesell M, Manning P, Milligan H, Müller S, Muys B, Nguyen D, Nock C, Ohse B, Paquette A, Peñuelas J, Pollastrini M, Radoglou K, Raulund-Rasmussen K, Roger F, Seidl R, Selvi F, Stenlid J, Valladares F, van Keer J, Vesterdal L, Fischer M, Gamfeldt L, Allan E. Continental mapping of forest ecosystem functions reveals a high but unrealised potential for forest multifunctionality. Ecol Lett 2017; 21:31-42. [PMID: 29143494 DOI: 10.1111/ele.12868] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 08/07/2017] [Accepted: 09/30/2017] [Indexed: 02/04/2023]
Abstract
Humans require multiple services from ecosystems, but it is largely unknown whether trade-offs between ecosystem functions prevent the realisation of high ecosystem multifunctionality across spatial scales. Here, we combined a comprehensive dataset (28 ecosystem functions measured on 209 forest plots) with a forest inventory dataset (105,316 plots) to extrapolate and map relationships between various ecosystem multifunctionality measures across Europe. These multifunctionality measures reflected different management objectives, related to timber production, climate regulation and biodiversity conservation/recreation. We found that trade-offs among them were rare across Europe, at both local and continental scales. This suggests a high potential for 'win-win' forest management strategies, where overall multifunctionality is maximised. However, across sites, multifunctionality was on average 45.8-49.8% below maximum levels and not necessarily highest in protected areas. Therefore, using one of the most comprehensive assessments so far, our study suggests a high but largely unrealised potential for management to promote multifunctional forests.
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Affiliation(s)
- Fons van der Plas
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013, Bern, Switzerland.,Senckenberg Gesellschaft für Naturforschung, Biodiversity and Climate Research Centre, Senckenberganlage 25, 60325, Frankfurt, Germany.,Department of Systematic Botany and Functional Biodiversity, University of Leipzig, Johannisallee 21-23, 04103, Leipzig, Germany
| | - Sophia Ratcliffe
- Department of Systematic Botany and Functional Biodiversity, University of Leipzig, Johannisallee 21-23, 04103, Leipzig, Germany
| | - Paloma Ruiz-Benito
- Biological and Environmental Sciences, School of Natural Sciences, University of Stirling, FK9 4LA, Stirling, UK.,Grupo de Ecología y Restauración Forestal, Departamento de Ciencias de la Vida, Universidad de Alcalá, Edificio de Ciencias, Campus Universitario, 28805, Alcalá de Henares, Madrid, Spain
| | | | - Kris Verheyen
- Forest & Nature Lab, Ghent University, Geraardsbergsesteenweg 267, B-9090, Melle-Gontrode, Belgium
| | - Christian Wirth
- Department of Systematic Botany and Functional Biodiversity, University of Leipzig, Johannisallee 21-23, 04103, Leipzig, Germany.,German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5E, 04103, Leipzig, Germany
| | - Miguel A Zavala
- Grupo de Ecología y Restauración Forestal, Departamento de Ciencias de la Vida, Universidad de Alcalá, Edificio de Ciencias, Campus Universitario, 28805, Alcalá de Henares, Madrid, Spain
| | - Evy Ampoorter
- Forest & Nature Lab, Ghent University, Geraardsbergsesteenweg 267, B-9090, Melle-Gontrode, Belgium
| | - Lander Baeten
- Forest & Nature Lab, Ghent University, Geraardsbergsesteenweg 267, B-9090, Melle-Gontrode, Belgium
| | - Luc Barbaro
- BIOGECO, INRA, Univ. Bordeaux, 33610, Cestas, France.,Dynafor, INPT-EI Purpan, INRA, Univ. Toulouse, 31320, Auzeville, France
| | | | - Jürgen Bauhus
- Faculty of Environment and Natural Resources, Chair of Silviculture, University of Freiburg, Fahnenbergplatz, 79085, Freiburg, Germany
| | - Raquel Benavides
- Faculty of Biology, Geobotany, University of Freiburg, Schänzlestr. 1, 79104, Freiburg, Germany
| | - Adam Benneter
- Faculty of Environment and Natural Resources, Chair of Silviculture, University of Freiburg, Fahnenbergplatz, 79085, Freiburg, Germany
| | | | - Olivier Bouriaud
- Faculty of Forestry, Stefan cel Mare University of Suceava, Universitatii Street 13, Suceava, 720229, Romania
| | - Helge Bruelheide
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5E, 04103, Leipzig, Germany.,Institute of Biology/Geobotany and Botanical Garden, Martin Luther University Halle-Wittenberg, Am Kirchtor, 1, 06108, Halle (Saale), Germany
| | - Filippo Bussotti
- Department of Agrifood Production and Environmental Sciences, Laboratory of Applied and Environmental Botany, University of Firenze, P.le Cascine 28, 50144, Firenze, Italy
| | - Monique Carnol
- Laboratory of Plant and Microbial Ecology, University of Liege, Botany B22, Chemin de la Vallee 4, 4000, Liege, Belgium
| | | | | | - Johannes H C Cornelissen
- Systems Ecology, Department of Ecological Science, Faculty of Earth and Life Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands
| | - Jonas Dahlgren
- Swedish University of Agricultural Sciences, Skogsmarksgränd, 90183, Umeå, Sweden
| | - Ewa Checko
- Bialowieza Geobotanical Station, Faculty of Biology, University of Warsaw, 17-230, Białowieża, Poland
| | - Andrea Coppi
- Department of Biology, Botanical Laboratories, University of Firenze, Via G. La Pira 4, 50121, Firenze, Italy
| | - Seid Muhie Dawud
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, 1958, Frederiksberg C, Denmark
| | - Marc Deconchat
- BIOGECO, INRA, Univ. Bordeaux, 33610, Cestas, France.,Dynafor, INPT-EI Purpan, INRA, Univ. Toulouse, 31320, Auzeville, France
| | - Pallieter De Smedt
- Forest & Nature Lab, Ghent University, Geraardsbergsesteenweg 267, B-9090, Melle-Gontrode, Belgium
| | - Hans De Wandeler
- Department of Earth and Environmental Sciences, KU Leuven, University of Leuven, Celestijnenlaan 200E Box 2411, BE-3001, Leuven, Belgium
| | - Timo Domisch
- Natural Resources Institute Finland (Luke), Yliopistokatu 6, FI-80100, Joensuu, Finland
| | - Leena Finér
- Natural Resources Institute Finland (Luke), Yliopistokatu 6, FI-80100, Joensuu, Finland
| | - Mariangela Fotelli
- Forest Research Institute of Thessaloniki, Greek Agricultural Organization-Dimitra, 57006, Vassilika, Thessaloniki, Greece
| | - Arthur Gessler
- Swiss Federal Research Institute WSL, Research Unit Forest Dynamics, Zuercherstr, 111, 8903, Birmensdorf, Switzerland
| | | | - Charlotte Grossiord
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Virginie Guyot
- BIOGECO, INRA, Univ. Bordeaux, 33610, Cestas, France.,Dynafor, INPT-EI Purpan, INRA, Univ. Toulouse, 31320, Auzeville, France
| | - Josephine Haase
- Faculty of Biology, Geobotany, University of Freiburg, Schänzlestr. 1, 79104, Freiburg, Germany.,Institute for Terrestrial Ecosystems, Department of Environmental Systems Science, ETH Zurich, Universitaetsstrasse 16, 8092, Zurich, Switzerland
| | - Stephan Hättenschwiler
- Centre of Evolutionary and Functional Ecology (CEFE UMR 5175, CNRS - University of Montpellier - University Paul-Valery Montpellier - EPHE), 1919 route de Mende, 34293, Montpellier, France
| | - Hervé Jactel
- BIOGECO, INRA, Univ. Bordeaux, 33610, Cestas, France
| | - Bogdan Jaroszewicz
- Bialowieza Geobotanical Station, Faculty of Biology, University of Warsaw, 17-230, Białowieża, Poland
| | - François-Xavier Joly
- Centre of Evolutionary and Functional Ecology (CEFE UMR 5175, CNRS - University of Montpellier - University Paul-Valery Montpellier - EPHE), 1919 route de Mende, 34293, Montpellier, France
| | - Tommaso Jucker
- Forest Ecology and Conservation, Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
| | - Stephan Kambach
- Institute of Biology/Geobotany and Botanical Garden, Martin Luther University Halle-Wittenberg, Am Kirchtor, 1, 06108, Halle (Saale), Germany.,Department Community Ecology, UFZ - Helmholtz Centre for Environmental Research, 06120, Halle (Saale), Germany
| | - Gerald Kaendler
- Forest Research Institute Baden-Wurttemberg, Wonnhaldestrase 4, 79100, Freiburg, Germany
| | - Jens Kattge
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5E, 04103, Leipzig, Germany.,Max Planck Institute for Biogeochemistry, Hans-Knöll-Straβe 10, 07745, Jena, Germany
| | - Julia Koricheva
- School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK
| | - Georges Kunstler
- Univ. Grenoble Alpes, Irstea, UR EMGR, Centre de Grenoble, 2 rue de la Papeterie-BP 76, F-38402, Saint-Martin-d'Hères, France
| | - Aleksi Lehtonen
- Natural Resources Institute Finland (Luke), Jokiniemenkuja 1, FI-01370, Vantaa, Finland
| | - Mario Liebergesell
- Department of Systematic Botany and Functional Biodiversity, University of Leipzig, Johannisallee 21-23, 04103, Leipzig, Germany.,German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5E, 04103, Leipzig, Germany
| | - Peter Manning
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013, Bern, Switzerland.,Senckenberg Gesellschaft für Naturforschung, Biodiversity and Climate Research Centre, Senckenberganlage 25, 60325, Frankfurt, Germany
| | - Harriet Milligan
- School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK
| | - Sandra Müller
- Faculty of Biology, Geobotany, University of Freiburg, Schänzlestr. 1, 79104, Freiburg, Germany
| | - Bart Muys
- Department of Earth and Environmental Sciences, KU Leuven, University of Leuven, Celestijnenlaan 200E Box 2411, BE-3001, Leuven, Belgium
| | - Diem Nguyen
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, PO Box 7026, SE-750 07, Uppsala, Sweden
| | - Charles Nock
- Faculty of Biology, Geobotany, University of Freiburg, Schänzlestr. 1, 79104, Freiburg, Germany
| | - Bettina Ohse
- Department of Systematic Botany and Functional Biodiversity, University of Leipzig, Johannisallee 21-23, 04103, Leipzig, Germany
| | - Alain Paquette
- Centre for Forest Research (CFR), Université du Québec à Montréal, Montréal, Québec, Canada
| | - Josep Peñuelas
- CREAF, Cerdanyola del Vallès, 08913, Catalonia, Spain.,CSIC, Global Ecology Unit, CREAF-CSIC-UB-UAB, Bellaterra, 08913, Catalonia, Spain
| | - Martina Pollastrini
- Department of Agrifood Production and Environmental Sciences, Laboratory of Applied and Environmental Botany, University of Firenze, P.le Cascine 28, 50144, Firenze, Italy
| | - Kalliopi Radoglou
- Democritus University of Thrace (DUTH), Department of Forestry and Management of the Environment and Natural Resources, Pantazidou 193, 68200, Nea Orestiada, Greece
| | - Karsten Raulund-Rasmussen
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, 1958, Frederiksberg C, Denmark
| | - Fabian Roger
- Department of Marine Sciences, University of Gothenburg, Carl Skottsbergs gata 22B, 41319, Göteborg, Sweden
| | - Rupert Seidl
- University of Natural Resources and Life Sciences (BOKU), Institute of Silviculture, Vienna, Austria
| | - Federico Selvi
- Department of Agrifood Production and Environmental Sciences, Laboratory of Applied and Environmental Botany, University of Firenze, P.le Cascine 28, 50144, Firenze, Italy
| | - Jan Stenlid
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, PO Box 7026, SE-750 07, Uppsala, Sweden
| | | | | | - Lars Vesterdal
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, 1958, Frederiksberg C, Denmark
| | - Markus Fischer
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013, Bern, Switzerland.,Senckenberg Gesellschaft für Naturforschung, Biodiversity and Climate Research Centre, Senckenberganlage 25, 60325, Frankfurt, Germany
| | - Lars Gamfeldt
- Department of Marine Sciences, University of Gothenburg, Carl Skottsbergs gata 22B, 41319, Göteborg, Sweden
| | - Eric Allan
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013, Bern, Switzerland
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Ratcliffe S, Wirth C, Jucker T, van der Plas F, Scherer-Lorenzen M, Verheyen K, Allan E, Benavides R, Bruelheide H, Ohse B, Paquette A, Ampoorter E, Bastias CC, Bauhus J, Bonal D, Bouriaud O, Bussotti F, Carnol M, Castagneyrol B, Chećko E, Dawud SM, Wandeler HD, Domisch T, Finér L, Fischer M, Fotelli M, Gessler A, Granier A, Grossiord C, Guyot V, Haase J, Hättenschwiler S, Jactel H, Jaroszewicz B, Joly FX, Kambach S, Kolb S, Koricheva J, Liebersgesell M, Milligan H, Müller S, Muys B, Nguyen D, Nock C, Pollastrini M, Purschke O, Radoglou K, Raulund-Rasmussen K, Roger F, Ruiz-Benito P, Seidl R, Selvi F, Seiferling I, Stenlid J, Valladares F, Vesterdal L, Baeten L. Biodiversity and ecosystem functioning relations in European forests depend on environmental context. Ecol Lett 2017; 20:1414-1426. [DOI: 10.1111/ele.12849] [Citation(s) in RCA: 183] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 06/30/2017] [Accepted: 08/13/2017] [Indexed: 01/02/2023]
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6
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Tuzet A, Granier A, Betsch P, Peiffer M, Perrier A. Modelling hydraulic functioning of an adult beech stand under non-limiting soil water and severe drought condition. Ecol Modell 2017. [DOI: 10.1016/j.ecolmodel.2017.01.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Musavi T, Migliavacca M, van de Weg MJ, Kattge J, Wohlfahrt G, van Bodegom PM, Reichstein M, Bahn M, Carrara A, Domingues TF, Gavazzi M, Gianelle D, Gimeno C, Granier A, Gruening C, Havránková K, Herbst M, Hrynkiw C, Kalhori A, Kaminski T, Klumpp K, Kolari P, Longdoz B, Minerbi S, Montagnani L, Moors E, Oechel WC, Reich PB, Rohatyn S, Rossi A, Rotenberg E, Varlagin A, Wilkinson M, Wirth C, Mahecha MD. Potential and limitations of inferring ecosystem photosynthetic capacity from leaf functional traits. Ecol Evol 2016; 6:7352-7366. [PMID: 28725403 PMCID: PMC5513259 DOI: 10.1002/ece3.2479] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 08/13/2016] [Accepted: 08/24/2016] [Indexed: 01/22/2023] Open
Abstract
The aim of this study was to systematically analyze the potential and limitations of using plant functional trait observations from global databases versus in situ data to improve our understanding of vegetation impacts on ecosystem functional properties (EFPs). Using ecosystem photosynthetic capacity as an example, we first provide an objective approach to derive robust EFP estimates from gross primary productivity (GPP) obtained from eddy covariance flux measurements. Second, we investigate the impact of synchronizing EFPs and plant functional traits in time and space to evaluate their relationships, and the extent to which we can benefit from global plant trait databases to explain the variability of ecosystem photosynthetic capacity. Finally, we identify a set of plant functional traits controlling ecosystem photosynthetic capacity at selected sites. Suitable estimates of the ecosystem photosynthetic capacity can be derived from light response curve of GPP responding to radiation (photosynthetically active radiation or absorbed photosynthetically active radiation). Although the effect of climate is minimized in these calculations, the estimates indicate substantial interannual variation of the photosynthetic capacity, even after removing site-years with confounding factors like disturbance such as fire events. The relationships between foliar nitrogen concentration and ecosystem photosynthetic capacity are tighter when both of the measurements are synchronized in space and time. When using multiple plant traits simultaneously as predictors for ecosystem photosynthetic capacity variation, the combination of leaf carbon to nitrogen ratio with leaf phosphorus content explains the variance of ecosystem photosynthetic capacity best (adjusted R2 = 0.55). Overall, this study provides an objective approach to identify links between leaf level traits and canopy level processes and highlights the relevance of the dynamic nature of ecosystems. Synchronizing measurements of eddy covariance fluxes and plant traits in time and space is shown to be highly relevant to better understand the importance of intra- and interspecific trait variation on ecosystem functioning.
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Forrester DI, Bonal D, Dawud S, Gessler A, Granier A, Pollastrini M, Grossiord C. Drought responses by individual tree species are not often correlated with tree species diversity in European forests. J Appl Ecol 2016. [DOI: 10.1111/1365-2664.12745] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- David I. Forrester
- Chair of Silviculture; Faculty of Environment and Natural Resources; Freiburg University; Tennenbacherstr. 4 79108 Freiburg Germany
| | - Damien Bonal
- INRA; UMR EEF INRA-Université de Lorraine; 54280 Champenoux France
| | - Seid Dawud
- Department of Forestry; College of Agriculture; Wollo University; P.O. Box 1145 Dessie Ethiopia
| | - Arthur Gessler
- Swiss Federal Institute for Forest, Snow and Landscape Research; 8903 Birmensdorf Switzerland
- Berlin-Brandenburg Institute of Advanced Biodiversity Research; 14195 Berlin Germany
| | - André Granier
- INRA; UMR EEF INRA-Université de Lorraine; 54280 Champenoux France
| | - Martina Pollastrini
- Department of Agri-Food Production and Environmental Science; University of Florence; Piazzale delle Cascine 28 50144 Florence Italy
| | - Charlotte Grossiord
- Earth and Environmental Sciences Division; Los Alamos National Laboratory; Los Alamos NM 87545 USA
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Martin L, Granier A, Lemoine R, Dauba A, Vermeersch S, Aubert-Jacquin C, Baron C, Lebranchu Y, Hoarau C, Velge-Roussel F. Bifidobacteria BbC50 Fermentation Products Induce Human Cd4 + Regulatory T Cells with Antigen-Specific Activation and Bystander Suppression. EUR J INFLAMM 2014. [DOI: 10.1177/1721727x1401200116] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Probiotic bacteria have been shown to have health benefits in various situations (inflammation, allergy, infection). We previously showed that a bacteria-free fermentation product of Bifidobacterium breve C50 (BbC50sn) induced high IL-10 secretion by human dendritic cells. As IL-10 is a regulatory cytokine, the aim of the present study was to examine whether DCs cultured in the presence of BbC50sn could induce regulatory T cells in an allogeneic context. Purified CD4+CD25− human T cells were co-cultured with allogeneic BbC50sn-treated dendritic cells for 4 weeks. The T cell population (BbC50sn-T) was analysed both at phenotypical and functional [ability to inhibit a mixed lymphocyte reaction (MLR)] levels. We showed that T lymphocytes acquired phenotype characteristics of regulatory T cells after 4 weeks of co-culture with BbC50sn-DCs, and inhibited in vitro T lymphocyte proliferation and IFN-γ production in an MLR. Transwell experiments demonstrated that this suppressive activity was not T cell contact-dependent but probably mediated by a soluble factor. Although BbC50sn-T cells secreted significant amounts of IL-10 and TGF-β, their suppressive effect is most likely not mediated through these cytokines. This is, to our knowledge, the first demonstration of in vitro regulatory T cell induction by a bacteria-free fermentation product in an allogeneic context.
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Affiliation(s)
- L. Martin
- EA 4245 «Cellules Dendritiques, Immunomodulation et Greffes», UFR de Médecine, Université François-Rabelais de Tours, Tours, France
| | - A. Granier
- EA 4245 «Cellules Dendritiques, Immunomodulation et Greffes», UFR de Médecine, Université François-Rabelais de Tours, Tours, France
| | - R. Lemoine
- EA 4245 «Cellules Dendritiques, Immunomodulation et Greffes», UFR de Médecine, Université François-Rabelais de Tours, Tours, France
| | - A. Dauba
- EA 4245 «Cellules Dendritiques, Immunomodulation et Greffes», UFR de Médecine, Université François-Rabelais de Tours, Tours, France
| | - S. Vermeersch
- EA 4245 «Cellules Dendritiques, Immunomodulation et Greffes», UFR de Médecine, Université François-Rabelais de Tours, Tours, France
| | | | - C. Baron
- EA 4245 «Cellules Dendritiques, Immunomodulation et Greffes», UFR de Médecine, Université François-Rabelais de Tours, Tours, France
- Service de Néphrologie et d'Immunologie Clinique, CHRU de Tours, Tours, France
| | - Y. Lebranchu
- EA 4245 «Cellules Dendritiques, Immunomodulation et Greffes», UFR de Médecine, Université François-Rabelais de Tours, Tours, France
- Service de Néphrologie et d'Immunologie Clinique, CHRU de Tours, Tours, France
| | - C. Hoarau
- EA 4245 «Cellules Dendritiques, Immunomodulation et Greffes», UFR de Médecine, Université François-Rabelais de Tours, Tours, France
| | - F. Velge-Roussel
- EA 4245 «Cellules Dendritiques, Immunomodulation et Greffes», UFR de Médecine, Université François-Rabelais de Tours, Tours, France
- UFR des Sciences Pharmaceutiques, Tours, France
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10
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Grossiord C, Granier A, Gessler A, Jucker T, Bonal D. Does Drought Influence the Relationship Between Biodiversity and Ecosystem Functioning in Boreal Forests? Ecosystems 2013. [DOI: 10.1007/s10021-013-9729-1] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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11
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Gessler A, Brandes E, Keitel C, Boda S, Kayler ZE, Granier A, Barbour M, Farquhar GD, Treydte K. The oxygen isotope enrichment of leaf-exported assimilates--does it always reflect lamina leaf water enrichment? New Phytol 2013; 200:144-157. [PMID: 23763637 PMCID: PMC3902987 DOI: 10.1111/nph.12359] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Accepted: 05/09/2013] [Indexed: 05/12/2023]
Abstract
The oxygen stable isotope composition of plant organic matter (OM) (particularly of wood and cellulose in the tree ring archive) is valuable in studies of plant-climate interaction, but there is a lack of information on the transfer of the isotope signal from the leaf to heterotrophic tissues. We studied the oxygen isotopic composition and its enrichment above source water of leaf water over diel courses in five tree species covering a broad range of life forms. We tracked the transfer of the isotopic signal to leaf water-soluble OM and further to phloem-transported OM. Observed leaf water evaporative enrichment was consistent with values predicted from mechanistic models taking into account nonsteady-state conditions. While leaf water-soluble OM showed the expected (18)O enrichment in all species, phloem sugars were less enriched than expected from leaf water enrichment in Scots pine (Pinus sylvestris), European larch (Larix decidua) and Alpine ash (Eucalyptus delegatensis). Oxygen atom exchange with nonenriched water during phloem loading and transport, as well as a significant contribution of assimilates from bark photosynthesis, can explain these phloem (18)O enrichment patterns. Our results indicate species-specific uncoupling between the leaf water and the OM oxygen isotope signal, which is important for the interpretation of tree ring data.
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Affiliation(s)
- Arthur Gessler
- Leibniz Centre for Agricultural Landscape Research, Institute for Landscape BiogeochemistryEberswalderstr. 84, 15374, Müncheberg, Germany
- INRA, UMR 1137 Ecologie et Ecophysiologie Forestières INRA/Université de Lorraine54280, Champenoux, France
- Research School of Biology, Australian National UniversityBuilding 46, Acton, ACT, 0200, Autralia
| | - Elke Brandes
- INRA, UMR 1137 Ecologie et Ecophysiologie Forestières INRA/Université de Lorraine54280, Champenoux, France
| | - Claudia Keitel
- Research School of Biology, Australian National UniversityBuilding 46, Acton, ACT, 0200, Autralia
- Faculty of Agriculture and Environment, University of SydneyPrivate Bag 4011, Narellan, NSW, 2567, Australia
| | - Sonja Boda
- Swiss Federal Research Institute WSL, Research Unit Landscape DynamicsZürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
| | - Zachary E Kayler
- Leibniz Centre for Agricultural Landscape Research, Institute for Landscape BiogeochemistryEberswalderstr. 84, 15374, Müncheberg, Germany
| | - André Granier
- INRA, UMR 1137 Ecologie et Ecophysiologie Forestières INRA/Université de Lorraine54280, Champenoux, France
| | - Margaret Barbour
- Faculty of Agriculture and Environment, University of SydneyPrivate Bag 4011, Narellan, NSW, 2567, Australia
| | - Graham D Farquhar
- Research School of Biology, Australian National UniversityBuilding 46, Acton, ACT, 0200, Autralia
| | - Kerstin Treydte
- Swiss Federal Research Institute WSL, Research Unit Landscape DynamicsZürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
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12
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Grossiord C, Granier A, Gessler A, Scherer-Lorenzen M, Pollastrini M, Bonal D. Application of Loreau & Hector's (2001) partitioning method to complex functional traits. Methods Ecol Evol 2013. [DOI: 10.1111/2041-210x.12090] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Charlotte Grossiord
- INRA; UMR 1137 Ecologie et Ecophysiologie Forestières; 54280; Champenoux; France
| | - André Granier
- INRA; UMR 1137 Ecologie et Ecophysiologie Forestières; 54280; Champenoux; France
| | - Arthur Gessler
- Leibniz Centre for Agricultural Landscape Research (ZALF); Institute for Landscape Biogeochemistry; Eberswalderstr. 84 15374; Müncheberg; Germany
| | - Michael Scherer-Lorenzen
- Faculty of Biology/Geobotany; Universität Freiburg; Schänzlestrasse 1; D-79104; Freiburg; Germany
| | - Martina Pollastrini
- Department of Plant Biology; University of Florence; Piazzale delle Cascine 28; 50144; Firenze; Italy
| | - Damien Bonal
- INRA; UMR 1137 Ecologie et Ecophysiologie Forestières; 54280; Champenoux; France
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13
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Abstract
E-cadherins are homophilic adhesion molecules the expression of which is tightly linked to the invasiveness and the differentiated state of the cells. E-cadherin expression seems also inversely related to the expression of vimentin, an intermediate filament implicated in the metastatic potential of some cells. In breast tumor cells MCF-7, we have previously shown that calcium influences cell growth and promotes cell differentiation. In view of the importance of cell adhesion mechanisms in cell growth and invasion, we sought to determine whether calcium affects the regulation of E-cadherin expression and modifies the relationship between E-cadherin and vimentin expression. To address this question, cells were grown at low (0.04 mM) or high (2.5 mM) concentration of calcium and cadherin and vimentin expression was assessed by flow cytometry analyses. Our results show that calcium enhances cadherin expression in cadherin positive cells and decreases vimentin expression in these cells; in cadherin negative cells, calcium only decreases the expression of vimentin. The modifications of E-cadherin and/or vimentin expression suggests that drugs that can modify intracellular calcium may contribute to overcoming the progression of breast tumor cells toward increasingly malignant phenotypes.
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Affiliation(s)
- B Vandewalle
- CTR OSCAR LAMBRET,HEMATOL LAB,F-59020 LILLE,FRANCE
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14
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Vicca S, Gilgen AK, Camino Serrano M, Dreesen FE, Dukes JS, Estiarte M, Gray SB, Guidolotti G, Hoeppner SS, Leakey ADB, Ogaya R, Ort DR, Ostrogovic MZ, Rambal S, Sardans J, Schmitt M, Siebers M, van der Linden L, van Straaten O, Granier A. Urgent need for a common metric to make precipitation manipulation experiments comparable. New Phytol 2012; 195:518-522. [PMID: 22734795 DOI: 10.1111/j.1469-8137.2012.04224.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Affiliation(s)
- S Vicca
- Research Group of Plant and Vegetation Ecology, Department of Biology, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium
- (Author for correspondence: tel +32 3 265 22 82; email )
| | - A K Gilgen
- Institute of Agricultural Sciences, ETH Zurich, Universitätstrasse 2, 8092 Zurich, Switzerland
- Institute of Plant Sciences and Oeschger Centre for Climate Change Research, University of Bern, Altenbergrain 21, 3013 Bern, Switzerland
| | - M Camino Serrano
- Research Group of Plant and Vegetation Ecology, Department of Biology, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium
| | - F E Dreesen
- Research Group of Plant and Vegetation Ecology, Department of Biology, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium
| | - J S Dukes
- Department of Forestry and Natural Resources, Purdue University, 715 West State Street, West Lafayette, IN 47907-2061, USA
- Department of Biology, University of Massachusetts, Boston, MA 02125, USA
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - M Estiarte
- CREAF, Cerdanyola del Vallés 08193, Spain
- CSIC, Global Ecology Unit CREAF-CEAB-UAB, Cerdanyola del Vallés 08193, Spain
| | - S B Gray
- Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - G Guidolotti
- Department for Innovation in Biological, Agro-food and Forest Systems, University of Tuscia, Viterbo, Italy
| | - S S Hoeppner
- Department of Forestry and Natural Resources, Purdue University, 715 West State Street, West Lafayette, IN 47907-2061, USA
| | - A D B Leakey
- Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - R Ogaya
- CREAF, Cerdanyola del Vallés 08193, Spain
| | - D R Ort
- Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- USDA Agricultural Research Service, Urbana, IL 61801, USA
| | - M Z Ostrogovic
- Croatian Forest Research Institute, Cvjetno naselje 41, 10450 Jastrebarsko
| | - S Rambal
- CEFE-CNRS, 1919 route de Mende, 34000 Montpellier, France
| | - J Sardans
- CREAF, Cerdanyola del Vallés 08193, Spain
| | - M Schmitt
- Institute of Ecology, University of Innsbruck, Sternwartestr. 15, 6020 Innsbruck, Austria
| | - M Siebers
- Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - L van der Linden
- Australian Water Quality Centre, 250 Victoria Square, Adelaide SA 5000, Australia
| | - O van Straaten
- Buesgen Institute, Soil Science of Tropical and Subtropical Ecosystems, Georg-August-University of Goettingen, Buesgenweg 2, 37077, Goettingen, Germany
| | - A Granier
- INRA, UMR 1137 EEF, 54280 Champenoux, France
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15
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El Mel AA, Gautron E, Angleraud B, Granier A, Xu W, Choi CH, Briston KJ, Inkson BJ, Tessier PY. Fabrication of a nickel nanowire mesh electrode suspended on polymer substrate. Nanotechnology 2012; 23:275603. [PMID: 22706790 DOI: 10.1088/0957-4484/23/27/275603] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We report on an efficient strategy for the fabrication of an ultra-long suspended nanowire mesh suitable for nanodevice architectures on a polymer surface. First, nickel nanowires are synthesized directly on a template substrate by magnetron sputtering. Laser interference lithography followed by deep reactive ion etching is used to create the nanograted template substrate constituted of one-dimensional line pattern arrays of 240 nm in periodicity. Ordered alignment of ultra-long nanowires (∼180 nm in diameter) with high fidelity to the template pattern is observed by scanning electron microscopy. The transfer of the pre-defined parallel nanowire array from the template surface to a target polymer substrate for electrical characterization of the system is demonstrated. The electrical behaviour of the nanowire mesh, suspended between two electrodes, was found to be linear, stable, and reproducible. This result suggests that this nanofabrication process will open an efficient way to the design and construction of novel nanodevices.
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Affiliation(s)
- A A El Mel
- Université de Nantes, CNRS, Institut des Matériaux Jean Rouxel, UMR 6502, 2 rue de la Houssinière BP 32229-44322 Nantes cedex 3, France
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16
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El Mel AA, Achour A, Xu W, Choi CH, Gautron E, Angleraud B, Granier A, Le Brizoual L, Djouadi MA, Tessier PY. Hierarchical carbon nanostructure design: ultra-long carbon nanofibers decorated with carbon nanotubes. Nanotechnology 2011; 22:435302. [PMID: 21971265 DOI: 10.1088/0957-4484/22/43/435302] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Hierarchical carbon nanostructures based on ultra-long carbon nanofibers (CNF) decorated with carbon nanotubes (CNT) have been prepared using plasma processes. The nickel/carbon composite nanofibers, used as a support for the growth of CNT, were deposited on nanopatterned silicon substrate by a hybrid plasma process, combining magnetron sputtering and plasma-enhanced chemical vapor deposition (PECVD). Transmission electron microscopy revealed the presence of spherical nanoparticles randomly dispersed within the carbon nanofibers. The nickel nanoparticles have been used as a catalyst to initiate the growth of CNT by PECVD at 600°C. After the growth of CNT onto the ultra-long CNF, SEM imaging revealed the formation of hierarchical carbon nanostructures which consist of CNF sheathed with CNTs. Furthermore, we demonstrate that reducing the growth temperature of CNT to less than 500°C leads to the formation of carbon nanowalls on the CNF instead of CNT. This simple fabrication method allows an easy preparation of hierarchical carbon nanostructures over a large surface area, as well as a simple manipulation of such material in order to integrate it into nanodevices.
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Affiliation(s)
- A A El Mel
- Université de Nantes, CNRS, Institut des Matériaux Jean Rouxel, UMR 6502, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3, France
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17
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18
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Luais E, Thobie-Gautier C, Tailleur A, Djouadi MA, Granier A, Tessier P, Debarnot D, Poncin-Epaillard F, Boujtita M. Preparation and modification of carbon nanotubes electrodes by cold plasmas processes toward the preparation of amperometric biosensors. Electrochim Acta 2010. [DOI: 10.1016/j.electacta.2010.02.070] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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El Mel AA, Gautron E, Choi CH, Angleraud B, Granier A, Tessier PY. Titanium carbide/carbon composite nanofibers prepared by a plasma process. Nanotechnology 2010; 21:435603. [PMID: 20890019 DOI: 10.1088/0957-4484/21/43/435603] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The incorporation of metal or metal carbide nanoparticles into carbon nanofibers modifies their properties and enlarges their field of application. The purpose of this work is to report a new non-catalytic and easy method to prepare organized metal carbide-carbon composite nanofibers on nanopatterned silicon substrates prepared by laser interference lithography coupled with deep reactive ion etching. Titanium carbide-carbon composite nanofibers were grown on the top of the silicon lines parallel to the substrate by a hybrid plasma process combining physical vapor deposition and plasma enhanced chemical vapor deposition. The prepared nanofibers were analyzed by scanning electron microscopy, x-ray photoelectron spectroscopy, Raman spectroscopy and transmission electron microscopy. We demonstrate that the shape, microstructure and the chemical composition of the as-grown nanofibers can be tuned by changing the plasma conditions.
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Affiliation(s)
- A A El Mel
- Université de Nantes, CNRS, Institut des Matériaux Jean Rouxel, UMR 6502, Nantes, France
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20
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le Maire G, Delpierre N, Jung M, Ciais P, Reichstein M, Viovy N, Granier A, Ibrom A, Kolari P, Longdoz B, Moors EJ, Pilegaard K, Rambal S, Richardson AD, Vesala T. Detecting the critical periods that underpin interannual fluctuations in the carbon balance of European forests. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009jg001244] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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21
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Jouvet JC, Thomson V, Granier A, Perpoint T, Berthezène Y. [Answer to march e-quid. Association between balisar and brain involvement: it may be a tuberculosis]. J Radiol 2009; 90:520-522. [PMID: 19503038 DOI: 10.1016/s0221-0363(09)74016-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Affiliation(s)
- J C Jouvet
- Service de Radiologie Hôpital de la Croix Rousse, Lyon
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22
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Montpied P, Granier A, Dreyer E. Seasonal time-course of gradients of photosynthetic capacity and mesophyll conductance to CO2 across a beech (Fagus sylvatica L.) canopy. J Exp Bot 2009; 60:2407-18. [PMID: 19457983 DOI: 10.1093/jxb/erp093] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Leaf photosynthesis is known to acclimate to the actual irradiance received by the different layers of a canopy. This acclimation is usually described in terms of changes in leaf structure, and in photosynthetic capacity. Photosynthetic capacity is likely to be affected by mesophyll conductance to CO(2) which has seldom been assessed in tree species, and whose plasticity in response to local irradiance is still poorly known. Structural [N and chlorophyll content, leaf mass to area ratio (LMA)] and functional leaf traits [maximum carboxylation rate (V(cmax)), maximum light-driven electron flux (J(max)), and mesophyll conductance (g(i))] were assessed by measuring leaf response curves of net CO(2) assimilation versus intercellular CO(2) partial pressure, along a vertical profile across a beech canopy, and by fitting a version of the Farquhar model including g(i). The measurements were repeated five times during a growth season to catch potential seasonal variation. Irradiance gradients resulted in large decreasing gradients of LMA, g(i), V(cmax), and J(max). Relative allocation of leaf N to the different photosynthetic processes was only slightly affected by local irradiance. Seasonal changes after leaf expansion and before induction of leaf senescence were only minor. Structural equation modelling confirmed that LMA was the main driving force for changes in photosynthetic traits, with only a minor contribution of leaf Nitrogen content. In conclusion, mesophyll conductance to CO(2) displays a large plasticity that scales with photosynthetic capacity across a tree canopy, and that it is only moderately (if at all) affected by seasonal changes in the absence of significant soil water depletion.
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Affiliation(s)
- Pierre Montpied
- INRA, UMR, Ecologie et Ecophysiologie Forestières, Champenoux, France.
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23
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Luais E, Boujtita M, Gohier A, Tailleur A, Casimirius S, Djouadi MA, Granier A, Tessier PY. Integration of a carbon nanotube based electrode in silicon microtechnology to fabricate electrochemical transducers. Nanotechnology 2008; 19:435502. [PMID: 21832696 DOI: 10.1088/0957-4484/19/43/435502] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
An original approach was developed and validated for the fabrication of a carbon nanotube (CNT) electrode synthesized directly onto a carbon buffer thin film deposited on a highly doped monocrystalline silicon surface. The buffer layer of amorphous carbon thin film was deposited by physical vapour deposition on the silicon substrate before CNT synthesis. For this purpose, nickel was deposited on the carbon buffer layer by an electrochemical procedure and used as a catalyst for the CNT growth. The CNT synthesis was achieved by plasma enhanced chemical vapour deposition (PECVD) in an electron cyclotron resonance (ECR) plasma chamber using a C(2)H(2)/NH(3) gas mixture. In order to evaluate the electrochemical behaviour of the CNT-based electrode, the carbon layer and the silicon/carbon interface were studied. The resulting buffer layer enhanced the electronic transport from the doped silicon to the CNTs. The electrode surface was studied by XPS and characterized by both SEM and TEM. The electrochemical response exhibited by the resulting electrodes modified with CNTs was also examined by cyclic voltammetry. The whole process was found to be compatible with silicon microtechnology and could be envisaged for the direct integration of microsensors on silicon chips.
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Affiliation(s)
- E Luais
- Institut des Matériaux Jean Rouxel, IMN, Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes cedex 3, France. CEISAM, Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes cedex 3, France
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Do FC, Rocheteau A, Diagne AL, Goudiaby V, Granier A, Lhomme JP. Stable annual pattern of water use by Acacia tortilis in Sahelian Africa. Tree Physiol 2008; 28:95-104. [PMID: 17938118 DOI: 10.1093/treephys/28.1.95] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Water use by mature trees of Acacia tortilis (Forsk.) Hayne ssp. raddiana (Savi) Brenan var. raddiana growing in the northern Sahel was continuously recorded over 4 years. Water use was estimated from xylem sap flow measured by transient heat dissipation. Concurrently, cambial growth, canopy phenology, leaf water potential, climatic conditions and soil water availability (SWA) were monitored. In addition to the variation attributable to interannual variation in rainfall, SWA was increased by irrigation during one wet season. The wet season lasted from July to September, and annual rainfall ranged between 146 and 367 mm. The annual amount and pattern of tree water use were stable from year-to-year despite interannual and seasonal variations in SWA in the upper soil layers. Acacia tortilis transpired readily throughout the year, except for one month during the dry season when defoliation was at a maximum. Maximum water use of about 23 l (dm sapwood area)(-2) day(-1) was recorded at the end of the wet season. While trees retained foliage in the dry season, the decline in water use was modest at around 30%. Variation in predawn leaf water potential indicated that the trees were subject to soil water constraint. The rapid depletion of water in the uppermost soil layers after the wet season implies that there was extensive use of water from deep soil layers. The deep soil profile revealed (1) the existence of living roots at 25 m and (2) that the availability of soil water was low (-1.6 MPa) down to the water table at a depth of 31 m. However, transpiration was recorded at a predawn leaf water potential of -2.0 MPa, indicating that the trees used water from both intermediary soil layers and the water table. During the full canopy stage, mean values of whole-tree hydraulic conductance were similar in the wet and dry seasons. We propose that the stability of water use at the seasonal and annual scales resulted from a combination of features, including an extensive rooting habit related to deep water availability and an effective regulation of canopy conductance. Despite a limited effect on tree water use, irrigation during the wet season sharply increased predawn leaf water potential and cambial growth of trunks and branches.
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Affiliation(s)
- Frederic C Do
- Agronomy Section (IRD), Faculty of Agriculture, Khon kaen University, Khon Kaen, 40002 Thailand.
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Gohier A, Djouadi MA, Dubosc M, Granier A, Minea TM, Sirghi L, Rossi F, Paredez P, Alvarez F. Single- and few-walled carbon nanotubes grown at temperatures as low as 450 degrees c: electrical and field emission characterization. J Nanosci Nanotechnol 2007; 7:3350-3353. [PMID: 18019175 DOI: 10.1166/jnn.2007.883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Single-wall (SW-) and few-walled (FW-) carbon nanotubes (CNTs) were synthesized on aluminum/ cobalt coated silicon at temperatures as low as 450 degrees C by plasma enhanced chemical vapor deposition technique (PECVD). The SWCNTs and FWCNTs grow vertically oriented and well separated from each other. The cold field emission studies of as-grown SWCNTs and FWCNTs showed low turn-on field emission threshold voltages, strongly dependent of the nanotubes morphology. Current-voltage curves of individual CNTs, measured by conductive atomic force microscopy (CAFM), showed an electrical resistance of about 90 Komega, that is attributed mainly to the resistance of the contact between the CNTs and the conductive CAFM tip (Au and Pt).
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Affiliation(s)
- A Gohier
- Institut des Matériaux Jean Rouxel, IMN, Université de Nantes, UMR CNRS 6502, 2 rue de la Houssinière, 44322 Nantes, France
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Poyatos R, Martínez-Vilalta J, Cermák J, Ceulemans R, Granier A, Irvine J, Köstner B, Lagergren F, Meiresonne L, Nadezhdina N, Zimmermann R, Llorens P, Mencuccini M. Plasticity in hydraulic architecture of Scots pine across Eurasia. Oecologia 2007; 153:245-59. [PMID: 17453248 DOI: 10.1007/s00442-007-0740-0] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2006] [Accepted: 03/21/2007] [Indexed: 10/23/2022]
Abstract
Widespread tree species must show physiological and structural plasticity to deal with contrasting water balance conditions. To investigate these plasticity mechanisms, a meta-analysis of Pinus sylvestris L. sap flow and its response to environmental variables was conducted using datasets from across its whole geographical range. For each site, a Jarvis-type, multiplicative model was used to fit the relationship between sap flow and photosynthetically active radiation, vapour pressure deficit (D) and soil moisture deficit (SMD); and a logarithmic function was used to characterize the response of stomatal conductance (G(s)) to D. The fitted parameters of those models were regressed against climatic variables to study the acclimation of Scots pine to dry/warm conditions. The absolute value of sap flow and its sensitivity to D and SMD increased with the average summer evaporative demand. However, relative sensitivity of G(s) to D (m/G (s,ref), where m is the slope and G(s,ref) is reference G(s) at D = 1 kPa) did not increase with evaporative demand across populations, and transpiration per unit leaf area at a given D increased accordingly in drier/warmer climates. This physiological plasticity was linked to the previously reported climate- and size-related structural acclimation of leaf to sapwood area ratios. G (s,ref), and its absolute sensitivity to D(m), tended to decrease with age/height of the trees as previously reported for other pine species. It is unclear why Scots pines have higher transpiration rates at drier/warmer sites, at the expense of lower water-use efficiency. In any case, our results suggest that these structural adjustments may not be enough to prevent lower xylem tensions at the driest sites.
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Affiliation(s)
- R Poyatos
- Institute of Earth Sciences Jaume Almera, ICTJA-CSIC, Lluís Solé i Sabarís, s/n, 08028 Barcelona, Spain.
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Cotton F, Pellet O, Gilly FN, Granier A, Sournac L, Glehen O. MRI evaluation of bulky tumor masses in the mesentery and bladder involvement in peritoneal carcinomatosis. Eur J Surg Oncol 2006; 32:1212-6. [PMID: 16762527 DOI: 10.1016/j.ejso.2006.04.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2006] [Accepted: 04/20/2006] [Indexed: 11/28/2022] Open
Abstract
AIM Peritonectomy procedures with intraperitoneal chemohyperthermia are an effective but costly treatment for peritoneal carcinomatosis (PC). Consequently a proper selection of patients is necessary. We evaluated the benefit of MRI prior to surgery, in the detection of two of the main surgery contraindications: bulky mesenteric tumors and bladder implants. METHODS Three experts retrospectively reviewed abdominal and pelvic MRI from 19 cases of surgically proved PC (ovary: 7; colorectal: 7; gastric: 2; pseudomyxoma peritonei: 2; appendix: 1). RESULTS Mesenteric tumors were always identified as hypersignal masses on axial and coronal fat suppression gadolinium-enhanced T1 images (n=3). Three out of five bladder implants were detected. The two cases of bladder implants that were not detected on MRI were missed because the bladder was not filled. The best sequence for the detection of bladder involvement was axial T2-weighted images with bladder filling. CONCLUSIONS Evaluating the preoperative resectability of PC is crucial for patient management. MRI seems to reliably detect bulky mesenteric tumors and bladder implants on condition the bladder is filled and appropriate sequences are used.
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Affiliation(s)
- F Cotton
- Service de Radiologie, MRI Center, Centre Hospitalier Lyon Sud, 69495 Pierre Bénite Cedex, France.
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Ciais P, Reichstein M, Viovy N, Granier A, Ogée J, Allard V, Aubinet M, Buchmann N, Bernhofer C, Carrara A, Chevallier F, De Noblet N, Friend AD, Friedlingstein P, Grünwald T, Heinesch B, Keronen P, Knohl A, Krinner G, Loustau D, Manca G, Matteucci G, Miglietta F, Ourcival JM, Papale D, Pilegaard K, Rambal S, Seufert G, Soussana JF, Sanz MJ, Schulze ED, Vesala T, Valentini R. Europe-wide reduction in primary productivity caused by the heat and drought in 2003. Nature 2005; 437:529-33. [PMID: 16177786 DOI: 10.1038/nature03972] [Citation(s) in RCA: 1045] [Impact Index Per Article: 55.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2005] [Accepted: 06/23/2005] [Indexed: 11/09/2022]
Abstract
Future climate warming is expected to enhance plant growth in temperate ecosystems and to increase carbon sequestration. But although severe regional heatwaves may become more frequent in a changing climate, their impact on terrestrial carbon cycling is unclear. Here we report measurements of ecosystem carbon dioxide fluxes, remotely sensed radiation absorbed by plants, and country-level crop yields taken during the European heatwave in 2003. We use a terrestrial biosphere simulation model to assess continental-scale changes in primary productivity during 2003, and their consequences for the net carbon balance. We estimate a 30 per cent reduction in gross primary productivity over Europe, which resulted in a strong anomalous net source of carbon dioxide (0.5 Pg C yr(-1)) to the atmosphere and reversed the effect of four years of net ecosystem carbon sequestration. Our results suggest that productivity reduction in eastern and western Europe can be explained by rainfall deficit and extreme summer heat, respectively. We also find that ecosystem respiration decreased together with gross primary productivity, rather than accelerating with the temperature rise. Model results, corroborated by historical records of crop yields, suggest that such a reduction in Europe's primary productivity is unprecedented during the last century. An increase in future drought events could turn temperate ecosystems into carbon sources, contributing to positive carbon-climate feedbacks already anticipated in the tropics and at high latitudes.
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Affiliation(s)
- Ph Ciais
- Laboratoire des Sciences du Climat et de l'Environnement, LSCE, F-91191, Gif sur Yvette, France.
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Loustau D, Bosc A, Colin A, Ogée J, Davi H, François C, Dufrêne E, Déqué M, Cloppet E, Arrouays D, Le Bas C, Saby N, Pignard G, Hamza N, Granier A, Bréda N, Ciais P, Viovy N, Delage F. Modeling climate change effects on the potential production of French plains forests at the sub-regional level. Tree Physiol 2005; 25:813-23. [PMID: 15870051 DOI: 10.1093/treephys/25.7.813] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
We modeled the effects of climate change and two forest management scenarios on wood production and forest carbon balance in French forests using process-based models of forest growth. We combined data from the national forest inventory and soil network survey, which were aggregated over a 50 x 50-km grid, i.e., the spatial resolution of the climate scenario data. We predicted and analyzed the climate impact on potential forest production over the period 1960-2100. All models predicted a slight increase in potential forest yield until 2030-2050, followed by a plateau or a decline around 2070-2100, with overall, a greater increase in yield in northern France than in the south. Gross and net primary productivities were more negatively affected by soil water and atmospheric water vapor saturation deficits in western France because of a more pronounced shift in seasonal rainfall from summer to winter. The rotation-averaged values of carbon flux and production for different forest management options were estimated during four years (1980, 2015, 2045 and 2080). Predictions were made using a two-dimensional matrix covering the range of local soil and climate conditions. The changes in ecosystem fluxes and forest production were explained by the counterbalancing effect of rising CO2 concentration and increasing water deficit. The effect of climate change decreased with rotation length from short rotations with high production rates and low standing biomasses to long rotations with low productivities and greater standing biomasses. Climate effects on productivity, both negative and positive, were greatest on high fertility sites. Forest productivity in northern France was enhanced by climate change, increasingly from west to east, whereas in the southwestern Atlantic region, productivity was reduced by climate change to an increasing degree from west to east.
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Affiliation(s)
- Denis Loustau
- INRA-EPHYSE 69 route d'Arcachon, 33612 Gazinet Cédex, France.
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Baldocchi DD, Black TA, Curtis PS, Falge E, Fuentes JD, Granier A, Gu L, Knohl A, Pilegaard K, Schmid HP, Valentini R, Wilson K, Wofsy S, Xu L, Yamamoto S. Predicting the onset of net carbon uptake by deciduous forests with soil temperature and climate data: a synthesis of FLUXNET data. Int J Biometeorol 2005; 49:377-387. [PMID: 15688192 DOI: 10.1007/s00484-005-0256-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2004] [Revised: 10/21/2004] [Accepted: 12/30/2004] [Indexed: 05/24/2023]
Abstract
We tested the hypothesis that the date of the onset of net carbon uptake by temperate deciduous forest canopies corresponds with the time when the mean daily soil temperature equals the mean annual air temperature. The hypothesis was tested using over 30 site-years of data from 12 field sites where CO(2) exchange is being measured continuously with the eddy covariance method. The sites spanned the geographic range of Europe, North America and Asia and spanned a climate space of 16 degrees C in mean annual temperature. The tested phenology rule was robust and worked well over a 75 day range of the initiation of carbon uptake, starting as early as day 88 near Ione, California to as late as day 147 near Takayama, Japan. Overall, we observed that 64% of variance in the timing when net carbon uptake started was explained by the date when soil temperature matched the mean annual air temperature. We also observed a strong correlation between mean annual air temperature and the day that a deciduous forest starts to be a carbon sink. Consequently we are able to provide a simple phenological rule that can be implemented in regional carbon balance models and be assessed with soil and temperature outputs produced by climate and weather models.
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Affiliation(s)
- Dennis D Baldocchi
- Ecosystem Science Division, Department of Environmental Science, Policy and Management, University of California, 151 Hilgard Hall, Berkeley, CA 94720, USA.
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31
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Abstract
We investigated the radial variation of sap flow within sapwood below the live crown in relation to tree size in 10-, 32-, 54- and 91-year-old maritime pine stands (Pinus pinaster Ait.). Radial variations were determined with two thermal dissipation sensors; one measured sap flux in the outer 20 mm of the xylem (Jref), whereas the other was moved radially across the sapwood in 20-mm increments to measure sap flux at multiple depths (Jref). For all tree sizes, sap flow ratios (Ri = JiJref (-1)) declined with increasing sapwood depth, but the decrease was steeper in trees with large diameters. Correction factors (C) were calculated to extrapolate Jref for an estimate of whole-tree sap flux. A negative linear relationship was established between stem diameter and C, the latter ranging from 0.6 to 1.0. We found that neglecting these radial corrections in 10-, 32-, 54- and 91-year-old trees would lead to overestimation of stand transpiration by 4, 14, 26 and 47%, respectively. Therefore, it is necessary to account for the differential radial profiles of sap flow in relation to tree size when comparing tree transpiration and hydraulic properties among trees differing in size.
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Affiliation(s)
- Sylvain Delzon
- Unité-EPHYSE, INRA, 69 route d'Arcachon, 33612 GAZINET Cedex, France.
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Sarangi D, Godon C, Granier A, Goullet A, Turban G, Chauvet O. Growth mechanisms of carbon nanotubes converted from diamond-like carbon films. Chem Phys Lett 2004. [DOI: 10.1016/j.cplett.2004.09.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Roupsard O, Ferhi A, Granier A, Pallo F, Depommier D, Mallet B, Joly HI, Dreyer E. Reverse phenology and dry‐season water uptake byFaidherbia albida(Del.) A. Chev. in an agroforestry parkland of Sudanese west Africa. Funct Ecol 2002. [DOI: 10.1046/j.1365-2435.1999.00345.x] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- O. Roupsard
- CIRAD‐Forêt, Campus International de Baillarguet, BP 5035, F‐34032 Montpellier Cedex 01, France,,
- INERA‐Productions Forestières, 03 BP 7047 03, Ouagadougou, Burkina Faso,,
- INRA‐Nancy, UR Ecophysiologie Forestière, Equipe Bioclimatologie et Ecophysiologie Forestière, F‐54280 Champenoux, France
| | - A. Ferhi
- Centre de Recherches Géodynamiques, Université de Paris VI, F‐74203 Thonon‐les‐Bains, France and,
| | - A. Granier
- INRA‐Nancy, UR Ecophysiologie Forestière, Equipe Bioclimatologie et Ecophysiologie Forestière, F‐54280 Champenoux, France
| | - F. Pallo
- INERA‐Productions Forestières, 03 BP 7047 03, Ouagadougou, Burkina Faso,,
| | - D. Depommier
- CIRAD‐Forêt, Campus International de Baillarguet, BP 5035, F‐34032 Montpellier Cedex 01, France,,
- INERA‐Productions Forestières, 03 BP 7047 03, Ouagadougou, Burkina Faso,,
| | - B. Mallet
- CIRAD‐Forêt, Campus International de Baillarguet, BP 5035, F‐34032 Montpellier Cedex 01, France,,
| | - H. I. Joly
- CIRAD‐Forêt, Campus International de Baillarguet, BP 5035, F‐34032 Montpellier Cedex 01, France,,
| | - E. Dreyer
- INRA‐Nancy, UR Ecophysiologie Forestière, Equipe Bioclimatologie et Ecophysiologie Forestière, F‐54280 Champenoux, France
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35
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Granier A, Ceschia E, Damesin C, Dufrêne E, Epron D, Gross P, Lebaube S, Le Dantec V, Le Goff N, Lemoine D, Lucot E, Ottorini JM, Pontailler JY, Saugier B. The carbon balance of a young Beech forest. Funct Ecol 2001. [DOI: 10.1046/j.1365-2435.2000.00434.x] [Citation(s) in RCA: 220] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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36
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Epron D, Le Dantec V, Dufrene E, Granier A. Seasonal dynamics of soil carbon dioxide efflux and simulated rhizosphere respiration in a beech forest. Tree Physiol 2001; 21:145-52. [PMID: 11303645 DOI: 10.1093/treephys/21.2-3.145] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Respiration of the rhizosphere in a beech (Fagus sylvatica L.) forest was calculated by subtracting microbial respiration associated with organic matter decomposition from daily mean soil CO2 efflux. We used a semi-mechanistic soil organic matter model to simulate microbial respiration, which was validated against "no roots" data from trenched subplots. Rhizosphere respiration exhibited pronounced seasonal variation from 0.2 g C m(-2) day(-1) in January to 2.3 g C m(-2) day(-1) in July. Rhizosphere respiration accounted for 30 to 60% of total soil CO2 efflux, with an annual mean of 52%. The high Q10 (3.9) for in situ rhizosphere respiration was ascribed to the confounding effects of temperature and changes in root biomass and root and shoot activities. When data were normalized to the same soil temperature based on a physiologically relevant Q10 value of 2.2, the lowest values of temperature-normalized rhizosphere respiration were observed from January to March, whereas the highest value was observed in early July when fine root growth is thought to be maximal.
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Affiliation(s)
- D Epron
- Laboratoire de Biologie et Ecophysiologie, Institut des Sciences et des Techniques de l'Environnement, Université de Franche-Comté, Montbéliard, France
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Abstract
Hydraulic conductivity in the terminal branches of mature beech trees (Fagus sylvatica L.) decreased progressively during winter and recovered in the spring. The objective of this study was to determine the mechanisms involved in recovery. Two periods of recovery were identified. The first recovery of hydraulic conductivity occurred early in the spring, before bud break, and was correlated with the occurrence of positive xylem pressure at the base of the tree trunk. Active refilling of the embolized vessels caused the recovery. The second recovery of hydraulic conductivity occurred after bud break and was correlated with the onset of cambial activity. Formation of new functional vessels, leading to an increase in xylem diameter, was largely responsible for the increase in xylem conductivity. The two mechanisms were complementary: active refilling of embolized vessels occurred mostly in the root and the trunk, whereas formation of new functional vessels occurred mainly in young terminal shoots.
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Affiliation(s)
- H Cochard
- UMR-PIAF, INRA-UBP, Clermont-Ferrand, France
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Valentini R, Matteucci G, Dolman AJ, Schulze ED, Rebmann C, Moors EJ, Granier A, Gross P, Jensen NO, Pilegaard K, Lindroth A, Grelle A, Bernhofer C, Grünwald T, Aubinet M, Ceulemans R, Kowalski AS, Vesala T, Rannik U, Berbigier P, Loustau D, Gudmundsson J, Thorgeirsson H, Ibrom A, Morgenstern K, Clement R. Respiration as the main determinant of carbon balance in European forests. Nature 2000; 404:861-5. [PMID: 10786790 DOI: 10.1038/35009084] [Citation(s) in RCA: 1216] [Impact Index Per Article: 50.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Carbon exchange between the terrestrial biosphere and the atmosphere is one of the key processes that need to be assessed in the context of the Kyoto Protocol. Several studies suggest that the terrestrial biosphere is gaining carbon, but these estimates are obtained primarily by indirect methods, and the factors that control terrestrial carbon exchange, its magnitude and primary locations, are under debate. Here we present data of net ecosystem carbon exchange, collected between 1996 and 1998 from 15 European forests, which confirm that many European forest ecosystems act as carbon sinks. The annual carbon balances range from an uptake of 6.6 tonnes of carbon per hectare per year to a release of nearly 1 t C ha(-1) yr(-1), with a large variability between forests. The data show a significant increase of carbon uptake with decreasing latitude, whereas the gross primary production seems to be largely independent of latitude. Our observations indicate that, in general, ecosystem respiration determines net ecosystem carbon exchange. Also, for an accurate assessment of the carbon balance in a particular forest ecosystem, remote sensing of the normalized difference vegetation index or estimates based on forest inventories may not be sufficient.
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Affiliation(s)
- R Valentini
- University of Tuscia, Department of Forest Environment and Resources, Viterbo, Italy.
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Granier A. Prévention de la prématurité: mise à l'heure de « l'horloge placentaire. Arch Pediatr 1999. [DOI: 10.1016/s0929-693x(00)88490-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Granier A. Informations pour le praticien. Arch Pediatr 1999. [DOI: 10.1016/s0929-693x(99)80568-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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41
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Granier A, Bréda N, Biron P, Villette S. A lumped water balance model to evaluate duration and intensity of drought constraints in forest stands. Ecol Modell 1999. [DOI: 10.1016/s0304-3800(98)00205-1] [Citation(s) in RCA: 241] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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42
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Aubinet M, Grelle A, Ibrom A, Rannik Ü, Moncrieff J, Foken T, Kowalski A, Martin P, Berbigier P, Bernhofer C, Clement R, Elbers J, Granier A, Grünwald T, Morgenstern K, Pilegaard K, Rebmann C, Snijders W, Valentini R, Vesala T. Estimates of the Annual Net Carbon and Water Exchange of Forests: The EUROFLUX Methodology. ADV ECOL RES 1999. [DOI: 10.1016/s0065-2504(08)60018-5] [Citation(s) in RCA: 1366] [Impact Index Per Article: 54.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
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43
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Fort C, Muller F, Label P, Granier A, Dreyer E. Stomatal conductance, growth and root signaling in Betula pendula seedlings subjected to partial soil drying. Tree Physiol 1998; 18:769-776. [PMID: 12651411 DOI: 10.1093/treephys/18.11.769] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Seedlings of Betula pendula Roth were grown with their root systems separated between two soil compartments. Four treatments were imposed: (i) adequate irrigation in both compartments (WW, controls); (ii) adequate irrigation in one compartment and drought in the other compartment (WD); (iii) drought in both compartments (DD); and (iv) half of the root system severed and the remainder kept well-watered (root excision, RE). Predawn leaf water potential, stomatal conductance, soil-to-leaf specific hydraulic conductance, and root and leaf growth decreased in DD-treated seedlings, which also displayed severe leaf shedding (30% loss in leaf area). The DD treatment also resulted in increased concentrations of abscisic acid (ABA) and its glucose ester in the xylem sap of roots and shoots compared to concentrations in control seedlings (about 200 versus 20 nM). Despite the difference in xylem sap concentrations, total ABA flux to the shoots was similar in the two treatments (1-2 pmol ABA m(-2) leaf area s(-1)) as a result of reduced transpiration in the DD-treated seedlings. Compared with root growth in control plants, root growth increased in the RE-treated plants and decreased in the drying compartment of the WD treatment; however, the RE and WD treatments only slightly reduced leaf expansion, and had no detectable effects on shoot water relations or ABA concentrations of the root and shoot xylem sap. We conclude that short-term soil water depletion affecting only 50% of the root system does not cause a measurable stress response in birch shoots, despite root growth cessation in the fraction of drying soil.
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Affiliation(s)
- C. Fort
- Equipe Bioclimatologie et Ecophysiologie, Unité d'Ecophysiologie Forestière, INRA Nancy, F-54280 Champenoux, France
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Tenhunen JD, Valentini R, Köstner B, Zimmermann R, Granier A. Variation in forest gas exchange at landscape to continental scales. ACTA ACUST UNITED AC 1998. [DOI: 10.1051/forest:19980101] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Saugier B, Granier A, Pontailler JY, Dufrêne E, Baldocchi DD. Transpiration of a boreal pine forest measured by branch bag, sap flow and micrometeorological methods. Tree Physiol 1997; 17:511-519. [PMID: 14759824 DOI: 10.1093/treephys/17.8-9.511] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Three independent methods were used to evaluate transpiration of a boreal forest: the branch bag, sap flow and eddy covariance methods. The branch bag method encloses several thousand needles and gives a continuous record of branch transpiration. The sap flow method provides a continuous record of sap velocity and an estimate of tree transpiration. The eddy covariance method typically measures evaporation rates between a forest and the atmosphere. We deployed an extra eddy covariance system below the forest to estimate canopy transpiration by difference. The three systems detected small water vapor fluxes despite a plentiful supply of energy to drive evaporation. We also observed that transpiration rates were low even when the soil was well supplied with water. Low rates of transpiration were attributed to the canopy's low leaf area index and the marked reduction in stomatal conductance as vapor pressure deficits increased. Water vapor fluxes, derived from the sap flow method, lagged behind those derived by the branch bag method by 1 to 2 h. The sap flow method also suffered from sampling errors caused by the non-uniformity of flow across the sapwood and the spatial variability of sapwood cross section throughout the forest. Despite technical difficulties associated with hourly measurements, daily totals of transpiration agreed well with values derived from micrometeorological systems.
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Affiliation(s)
- B. Saugier
- Ecophysiologie Végétale, CNRS URA 2154, Bâtiment 362, Université Paris-Sud, 91405 Orsay cedex, France
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Fort C, Fauveau ML, Muller F, Label P, Granier A, Dreyer E. Stomatal conductance, growth and root signaling in young oak seedlings subjected to partial soil drying. Tree Physiol 1997; 17:281-9. [PMID: 14759851 DOI: 10.1093/treephys/17.5.281] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Leaf conductance, water relations, growth, and abscisic acid (ABA) concentrations in xylem sap, root apices and leaves were assessed in oak seedlings (Quercus robur L.) grown with a root system divided between two compartments and subjected to one of four treatments: (a) well watered, WW; (b) half of root system exposed to soil drying and half kept well watered, WD; (c) whole root system exposed to drought, DD; and (d) half of root system severed, RE. Sharp decreases in plant stomatal conductance, leaf water potential, hydraulic conductance and leaf growth were observed during DD treatment. No significant differences in plant leaf water potential and stomatal conductance were detected between the WW and WD treatments. Nevertheless, the WD treatment resulted in inhibition of leaf expansion and stimulation of root elongation only in the well-watered compartment. Abscisic acid concentrations did not change in leaves, root tips, or xylem sap of WD- compared to WW-treated plants. Increased concentrations of ABA were observed in xylem sap from DD-treated plant roots, but the total flux of ABA to shoots was reduced compared to that in WW-treated plants, because of decreases in transpiration flux. Similar plant responses to the WD and RE treatments indicate that the responses observed in the WD-treated plants were probably not triggered by a positive signal originating from drying roots.
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Affiliation(s)
- C Fort
- Equipe Bioclimatologie et Ecophysiologie, Unité d'Ecophysiologie Forestière, INRA Nancy, F-54280 Champenoux, France
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Lu P, Biron P, Granier A, Cochard H. Water relations of adult Norway spruce (Picea abies (L) Karst) under soil drought in the Vosges mountains: whole-tree hydraulic conductance, xylem embolism and water loss regulation. ACTA ACUST UNITED AC 1996. [DOI: 10.1051/forest:19960108] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Bréda N, Granier A. Intra- and interannual variations of transpiration, leaf area index and radial growth of a sessile oak stand (Quercus petraea). ACTA ACUST UNITED AC 1996. [DOI: 10.1051/forest:19960232] [Citation(s) in RCA: 136] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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