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Author (up) Bréchet, L.; Ponton, S.; Alméras, T.; Bonal, D.; Epron, D. url  openurl
  Title Does spatial distribution of tree size account for spatial variation in soil respiration in a tropical forest? Type Journal Article
  Year 2011 Publication Plant and Soil Abbreviated Journal Plant Soil  
  Volume 347 Issue 1 Pages 293-303  
  Keywords Forest structure; Litterfall; Root mass; Soil respiration; Spatial variation; Tropical forest; aboveground production; forest inventory; litterfall; range size; size distribution; soil respiration; spatial distribution; spatial variation; stand dynamics; tropical forest  
  Abstract We explored the relationship between soil processes, estimated through soil respiration (Rsoil), and the spatial variation in forest structure, assessed through the distribution of tree size, in order to understand the determinism of spatial variations in Rsoil in a tropical forest. The influence of tree size was examined using an index (Ic) calculated for each tree as a function of (1) the trunk cross section area and (2) the distance from the measurement point. We investigated the relationships between Ic and litterfall, root mass and Rsoil, respectively. Strong significant relationships were found between Ic and both litterfall and root mass. Rsoil showed a large range of variations over the 1-ha experimental plot, from 1. 5 to 12. 6 gC m-2 d-1. The best relationship between Ic and Rsoil only explained 17% of the spatial variation in Rsoil. These results support the assumption that local spatial patterns in litter production and root mass depend on tree distribution in tropical forests. Our study also emphasizes the modest contribution of tree size distribution-which is mainly influenced by the presence of the biggest trees (among the large range size of the inventoried trees greater than 10 cm diameter at 1. 30 m above ground level or at 0. 5 m above the buttresses)-in explaining spatial variations in Rsoil. © 2011 Springer Science+Business Media B.V.  
  Address Nancy Université, Université Henri Poincaré, UMR 1137, Ecologie et Ecophysiologie Forestières, Faculté des Sciences, 54500 Vandoeuvre les Nancy, France  
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  ISSN 0032079x (Issn) ISBN Medium  
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  Notes Export Date: 21 October 2011; Source: Scopus; Coden: Plsoa; doi: 10.1007/s11104-011-0848-1; Language of Original Document: English; Correspondence Address: Bréchet, L.; INRA, UMR Ecologie des Forêts de Guyane, Campus Agronomique, BP 709, 97387 Kourou cedex, French Guiana; email: laetitiabrechet@yahoo.fr Approved no  
  Call Number EcoFoG @ webmaster @ Serial 345  
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Author (up) Bréchet, Laëtitia M.; Daniel Warren; Stahl, Clément; Burban, Benoït; Goret, Jean-Yves; Salomon, Roberto L.; Janssens, Ivan A.o doi  openurl
  Title Simultaéneous tree stem and soil greenhouse gas (CO2, CH4, N2O) flux measurements: a novel design for continuous monitoring towards improving flux estimates and temporal resolution Type Journal Article
  Year 2021 Publication New Phytologist Abbreviated Journal  
  Volume 230 Issue 6 Pages 2487-2500  
  Keywords système de chambre automatisé ; efflux de dioxyde de carbone ; flux de méthane ; flux d'oxyde nitreux ; tige d'arbre ; forêt tropicale  
  Abstract Tree stems and soils can act as sources and sinks for the greenhouse gases (GHG) carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). Since both uptake and emission capacities can be large, especially in tropical rainforests, accurate assessments of the magnitudes and temporal variations of stem and soil GHG fluxes are required. We designed a new flexible stem chamber system for continuously measuring GHG fluxes in a French Guianese rainforest. Here, we describe this new system, which is connected to an automated soil GHG flux system, and discuss measurement uncertainty and potential error sources. In line with findings for soil GHG flux estimates, we demonstrated that lengthening the stem chamber closure time was required for accurate estimates of tree stem CH4 and N2O flux but not tree stem CO2 flux. The instrumented stem was a net source of CO2 and CH4 and a weak sink of N2O. Our experimental setup operated successfully in situ and provided continuous tree and soil GHG measurements at a high temporal resolution over an 11-month period. This automated system is a major step forward in the measurement of GHG fluxes in stems and the atmosphere concurrently with soil GHG fluxes in tropical forest ecosystems.  
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  Publisher New Phytologist Foundation Place of Publication Editor  
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  Call Number EcoFoG @ webmaster @ Serial 1004  
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Author (up) Brémaud, I.; El Kaïm, Y.; Guibal, D.; Minato, K.; Thibaut, B.; Gril, J. url  openurl
  Title Characterisation and categorisation of the diversity in viscoelastic vibrational properties between 98 wood types Type Journal Article
  Year 2012 Publication Annals of Forest Science Abbreviated Journal Ann. Forest Sci.  
  Volume 69 Issue 3 Pages 373-386  
  Keywords Damping coefficient; Dynamic mechanical properties; Specific dynamic modulus of elasticity; Specific gravity; Viscoelastic vibrational properties; Wood diversity  
  Abstract · Context Increased knowledge on diversity in wood properties would have implications both for fundamental research and for promoting a diversification of uses as material. · Aims The objective is to contribute to overcoming the critical lack of data on the diversity of wood dynamic mechanical/viscoelastic vibrational properties by testing lesser known species and categorising sources of variability. · Methods Air-dry axial specific dynamic modulus of elasticity (E′/γ) and damping coefficient (tand) were measured on a wide sampling (1,792 specimens) of 98 wood types from 79 species. An experimental device and protocol was designed for conducting systematic (i.e. rapid and reproducible) characterisations. · Results Diversity at the specimens' level corroborates the “standard” relationship between tanδ and E'/γ, which is discussed in terms of orientation of wood elements and of chemical composition. Diversity at the species level is expressed on the basis of results for normal heartwood, with specific gravity (γ) ranging from 0.2 to 1.3. Axial E'/γ ranges from 9 to 32 GPa and tand from 4×10 -3 to 19×10 -3. Properties distribution follows a continuum, but with group characteristics. The lowest values of tanδ are only found in certain tropical hardwoods. Results can also suggest alternative species for musical instruments making. · Conclusion The variations in specific gravity, in stiffness or in “viscosity” appear to be predominantly linked to different levels of diversity: between species or between wood types (reaction wood or taxonomy-related differences in heartwood extractives). © INRA/Springer-Verlag France 2011.  
  Address Wood Laboratory, EMPA, Überlandstrasse 129, 8600 Dübendorf, Switzerland  
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  ISSN 12864560 (Issn) ISBN Medium  
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  Notes Export Date: 20 June 2012; Source: Scopus; Coden: Afosf; doi: 10.1007/s13595-011-0166-z; Language of Original Document: English; Correspondence Address: Brémaud, I.; Wood Laboratory, EMPA, Überlandstrasse 129, 8600 Dübendorf, Switzerland; email: iris_bremaud@hotmail.com Approved no  
  Call Number EcoFoG @ webmaster @ Serial 403  
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Author (up) Brémaud, I.; Ruelle, J.; Thibaut, A.; Thibaut, B. doi  openurl
  Title Changes in viscoelastic vibrational properties between compression and normal wood: Roles of microfibril angle and of lignin Type Journal Article
  Year 2013 Publication Holzforschung Abbreviated Journal  
  Volume 67 Issue 1 Pages 75-85  
  Keywords Compression wood (CW); Damping coefficient; Ft-Ir; Internal friction; Lignin; Microfibril angle (MFA); Picea abies; Pinus pinaster; Pinus sylvestris; Specific dynamic modulus of elasticity; Viscoelastic vibrational properties  
  Abstract This study aims at better understanding the respective influences of specific gravity (γ ), microfibril angle (MFA), and cell wall matrix polymers on viscoelastic vibrational properties of wood in the axial direction. The wide variations of properties between normal wood (NW) and compression wood (CW) are in focus. Three young bent trees (Picea abies, Pinus sylvestris and Pinus pinaster ), which recovered verticality, were sampled. Several observed differences between NW and CW were highly significant in terms of anatomical, physical (γ, shrinkage, CIE Lab colorimetry), mechanical (compressive strength), and vibrational properties. The specific dynamic modulus of elasticity (E′/γ) decreases with increasing MFA, and Young's modulus (E′) can be satisfactorily explained by γ and MFA. Apparently, the type of the cell wall polymer matrix is not influential in this regard. The damping coefficient (tan δ) does not depend solely on the MFA of NW and CW. The tanδ-E′/γ relationship evidences that, at equivalent E′/γ, the tan δ of CW is approximately 34% lower than that of NW. This observation is ascribed to the more condensed nature of CW lignins, and this is discussed in the context of previous findings in other hygrothermal and time/frequency domains. It is proposed that the lignin structure and the amount and type of extractives, which are both different in various species, are partly responsible for taxonomy-related damping characteristics. Copyright © by Walter de Gruyter • Berlin • Boston.  
  Address Wood Laboratory, Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland  
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  Notes Export Date: 25 February 2013; Source: Scopus Approved no  
  Call Number EcoFoG @ webmaster @ Serial 471  
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Author (up) Brechet, L.; Ponton, S.; Roy, J.; Freycon, V.; Couteaux, M.M.; Bonal, D.; Epron, D. openurl 
  Title Do tree species characteristics influence soil respiration in tropical forests? A test based on 16 tree species planted in monospecific plots Type Journal Article
  Year 2009 Publication Plant and Soil Abbreviated Journal Plant Soil  
  Volume 319 Issue 1-2 Pages 235-246  
  Keywords Fine root; Litter quality; Nutrient cycling; Plant soil interactions; Soil respiration; Tropical plantations  
  Abstract The high spatial variability of soil respiration in tropical rainforests is well evaluated, but influences of biotic factors are not clearly understood. This study underlines the influence of tree species characteristics on soil respiration across a 16-monospecific plot design in a tropical plantation of French Guiana. A large variability of soil CO2 fluxes was observed among plots (i.e. 2.8 to 6.8 μmol m(-2) s(-1)) with the ranking being constant across seasons. There were no significant relationships between soil respiration and soil moisture or soil temperature, neither spatially, nor seasonally. The variability of soil respiration was mainly explained by quantitative factors such as leaf litterfall and basal area. Surprisingly, no significant relationship was observed between soil respiration and root biomass. However, the influence of substrate quality was revealed by a strong relationship between soil respiration and litterfall P (and litterfall N, to a lesser extent).  
  Address [Ponton, Stephane] Natl Inst Agr Res INRA Ctr Rech Nancy, Forest Ecol & Ecophysiol Unit, UMR EEF, F-54280 Seichamps, France, Email: ponton@nancy.inra.fr  
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  Publisher SPRINGER Place of Publication Editor  
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  Series Volume Series Issue Edition  
  ISSN 0032-079X ISBN Medium  
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  Notes ISI:000266143400020 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 110  
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Author (up) Bremaud, I.; Amusant, N.; Minato, K.; Gril, J.; Thibaut, B. openurl 
  Title Effect of extractives on vibrational properties of African Padauk (Pterocarpus soyauxii Taub.) Type Journal Article
  Year 2011 Publication Wood Science and Technology Abbreviated Journal Wood Sci. Technol.  
  Volume 45 Issue 3 Pages 461-472  
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  Abstract Extractives can affect the vibrational properties tan delta (damping coefficient) and E'/rho (specific Young's modulus), but this is highly dependent on species, compounds, and cellular locations. This paper investigates such effects for African Padauk (Pterocarpus soyauxii Taub.), a tropical hardwood with high extractives content and a preferred material for xylophones. Five groups of 26 heartwood specimens with large, yet comparable, ranges in vibrational properties were extracted in different solvents. Changes in vibrational properties were set against yields of extracts and evaluation of their cellular location. Methanol (ME) reached most of the compounds (13%), located about half in lumen and half in cell-wall. Water solubility was extremely low. tan delta and E'/rho were very strongly related (R (2) a parts per thousand yen 0.93), but native wood had abnormally low values of tan delta, while extraction shifted this relation towards higher tan delta values. ME extracted heartwood became in agreement with the average of many species, and close to sapwood. Extractions increased tan delta as much as 60%, irrespective of minute moisture changes or initial properties. Apparent E'/rho was barely changed (+2% to -4%) but, after correcting the mass contribution of extracts, it was in fact slightly reduced (down to -10% for high E'/rho), and increasingly so for specimens with low initial values of E'/rho.  
  Address [Bremaud, I; Minato, K] Kyoto Prefectural Univ, Lab Forest Resource Circulating Circles, Grad Sch Life & Environm Sci, Kyoto 6068522, Japan, Email: iris_bremaud@hotmail.com  
  Corporate Author Thesis  
  Publisher Springer Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0043-7719 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000292550700005 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 329  
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Author (up) Bremaud, I.; Cabrolier, P.; Gril, J.; Clair, B.; Gerard, J.; Minato, K.; Thibaut, B. openurl 
  Title Identification of anisotropic vibrational properties of Padauk wood with interlocked grain (vol 44, pg 335, 2010) Type Journal Article
  Year 2010 Publication Wood Science and Technology Abbreviated Journal Wood Sci. Technol.  
  Volume 44 Issue 4 Pages 705-705  
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  Abstract  
  Address [Bremaud, Iris; Minato, Kazuya] Kyoto Prefectural Univ, Grad Sch Life & Environm Sci, Lab Forest Resource Circulating Circles, Kyoto 6068522, Japan, Email: iris_bremaud@hotmail.com  
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  Series Volume Series Issue Edition  
  ISSN 0043-7719 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000283087900013 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 24  
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Author (up) Bremaud, I.; Cabrolier, P.; Gril, J.; Clair, B.; Gerard, J.; Minato, K.; Thibaut, B. openurl 
  Title Identification of anisotropic vibrational properties of Padauk wood with interlocked grain Type Journal Article
  Year 2010 Publication Wood Science and Technology Abbreviated Journal Wood Sci. Technol.  
  Volume 44 Issue 3 Pages 355-367  
  Keywords  
  Abstract Grain deviations and high extractives content are common features of many tropical woods. This study aimed at clarifying their respective impact on vibrational properties, referring to African Padauk (Pterocarpus soyauxii Taub.), a species selected for its interlocked grain, high extractives content and uses in xylophones. Specimens were cut parallel to the trunk axis (L), and local variations in grain angle (GA), microfibril angle (MFA), specific Young's modulus (E' (L) /rho, where rho stands for the density) and damping coefficient (tan delta(L)) were measured. GA dependence was analysed by a mechanical model which allowed to identify the specific Young's modulus (E'(3)/rho) and shear modulus (G'/rho) along the grain (3) as well as their corresponding damping coefficients (tan delta(3), tan delta(G)). This analysis was done for native and then for extracted wood. Interlocked grain resulted in 0-25A degrees GA and in variations of a factor 2 in E'(L)/rho and tan delta(L). Along the grain, Padauk wood was characterized, when compared to typical hardwoods, by a somewhat lower E'(3)/rho and elastic anisotropy (E'/G'), due to a wide microfibril angle plus a small weight effect of extracts, and a very low tan delta(3) and moderate damping anisotropy (tan delta(G)/tan delta(3)). Extraction affected mechanical parameters in the order: tan delta(3) a parts per thousand tan delta(G) > G'/rho > > E'(3)/rho. That is, extractives' effects were nearly isotropic on damping but clearly anisotropic on storage moduli.  
  Address [Bremaud, Iris; Minato, Kazuya] Kyoto Prefectural Univ, Grad Sch Life & Environm Sci, Lab Forest Resource Circulating Circles, Kyoto 6068522, Japan, Email: iris_bremaud@hotmail.com  
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  Publisher SPRINGER Place of Publication Editor  
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  ISSN 0043-7719 ISBN Medium  
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  Notes ISI:000280090400001 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 48  
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Author (up) Bremaud, I.; Gril, J.; Thibaut, B. openurl 
  Title Anisotropy of wood vibrational properties: dependence on grain angle and review of literature data Type Journal Article
  Year 2011 Publication Wood Science and Technology Abbreviated Journal Wood Sci. Technol.  
  Volume 45 Issue 4 Pages 735-754  
  Keywords  
  Abstract The anisotropy of vibrational properties influences the acoustic behaviour of wooden pieces and their dependence on grain angle (GA). As most pieces of wood include some GA, either for technological reasons or due to grain deviations inside trunks, predicting its repercussions would be useful. This paper aims at evaluating the variability in the anisotropy of wood vibrational properties and analysing resulting trends as a function of orientation. GA dependence is described by a model based on transformation formulas applied to complex compliances, and literature data on anisotropic vibrational properties are reviewed. Ranges of variability, as well as representative sets of viscoelastic anisotropic parameters, are defined for mean hardwoods and softwoods and for contrasted wood types. GA-dependence calculations are in close agreement with published experimental results and allow comparing the sensitivity of different woods to GA. Calculated trends in damping coefficient (tan delta) and in specific modulus of elasticity (E'/rho) allow reconstructing the general tan delta-E'/rho statistical relationships previously reported. Trends for woods with different mechanical parameters merge into a single curve if anisotropic ratios (both elastic and of damping) are correlated between them, and with axial properties, as is indicated by the collected data. On the other hand, varying damping coefficient independently results in parallel curves, which coincide with observations on chemically modified woods, either “artificially”, or by natural extractives.  
  Address [Bremaud, I; Gril, J] Univ Montpellier 2, Lab Mecan & Genie Civil, CNRS, CC048, F-34095 Montpellier 5, France, Email: iris_bremaud@hotmail.com  
  Corporate Author Thesis  
  Publisher Springer Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0043-7719 ISBN Medium  
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  Notes WOS:000296006000009 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 369  
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Author (up) Bremaud, I.; Minato, K.; Langbour, P.; Thibaut, B. openurl 
  Title Physico-chemical indicators of inter-specific variability in vibration damping of wood Type Journal Article
  Year 2010 Publication Annals of Forest Science Abbreviated Journal Ann. For. Sci.  
  Volume 67 Issue 7 Pages 707  
  Keywords damping coefficient; diversity of woods; extractives; physical properties; vibrational properties  
  Abstract The vibration damping coefficient (tan delta) of wood is an important property for acoustical uses, including musical instruments. Current difficulties in the availability of some of the preferred species call for diversification, but this comes up against the lack of systematic damping coefficient data. Keeping in mind the possible factors affecting tans, could we predict its variations between species, by using indicators that are either easily measured and/or readily available for many species? Vibrational properties, equilibrium moisture content and colorimetric parameters were assessed on 94 wood types belonging to 76 species. Experimental results were then related to data on chemical contents and physical properties from the CIRAD database. The “standard” relationship between tan delta and specific modulus of elasticity (E'/rho) explained only half of the variations. Deviations from this trend were correlated to extractives content, yet effects were not directly quantitative. Damping deviations were also correlated to colour and moisture-related properties, especially so with fibre saturation point. By taking into account a combination of moisture-related properties, colour – or extractives content, and the “standard” relationship between tans and E'/rho, we could propose simple predictive models which explain up to 89% of observed variations in tan delta between 48 species.  
  Address [Bremaud, Iris] Univ Montpellier 2, Lab Mecan & Genie Civil, CNRS, F-34095 Montpellier 5, France, Email: iris_bremaud@hotmail.com  
  Corporate Author Thesis  
  Publisher EDP SCIENCES S A Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1286-4560 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000283532000007 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 23  
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