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Author Coutand, C.; Chevolot, M.; Lacointe, A.; Rowe, N.; Scotti, I. openurl 
  Title (down) Mechanosensing of stem bending and its interspecific variability in five neotropical rainforest species Type Journal Article
  Year 2010 Publication Annals of Botany Abbreviated Journal Ann. Bot.  
  Volume 105 Issue 2 Pages 341-347  
  Keywords Mechanosensing; interspecific variability; trees; lianas; rain forest; neotropical species; bending; biomechanics; Bauhinia; Eperua; Symphonia; Tachigali  
  Abstract In rain forests, sapling survival is highly dependent on the regulation of trunk slenderness (height/diameter ratio): shade-intolerant species have to grow in height as fast as possible to reach the canopy but also have to withstand mechanical loadings (wind and their own weight) to avoid buckling. Recent studies suggest that mechanosensing is essential to control tree dimensions and stability-related morphogenesis. Differences in species slenderness have been observed among rainforest trees; the present study thus investigates whether species with different slenderness and growth habits exhibit differences in mechanosensitivity. Recent studies have led to a model of mechanosensing (sum-of-strains model) that predicts a quantitative relationship between the applied sum of longitudinal strains and the plant's responses in the case of a single bending. Saplings of five different neotropical species (Eperua falcata, E. grandiflora, Tachigali melinonii, Symphonia globulifera and Bauhinia guianensis) were subjected to a regimen of controlled mechanical loading phases (bending) alternating with still phases over a period of 2 months. Mechanical loading was controlled in terms of strains and the five species were subjected to the same range of sum of strains. The application of the sum-of-strain model led to a dose-response curve for each species. Dose-response curves were then compared between tested species. The model of mechanosensing (sum-of-strain model) applied in the case of multiple bending as long as the bending frequency was low. A comparison of dose-response curves for each species demonstrated differences in the stimulus threshold, suggesting two groups of responses among the species. Interestingly, the liana species B. guianensis exhibited a higher threshold than other Leguminosae species tested. This study provides a conceptual framework to study variability in plant mechanosensing and demonstrated interspecific variability in mechanosensing.  
  Address [Coutand, Catherine; Lacointe, Andre] Univ Clermont Ferrand, INRA, PIAF, UMR 547, F-63000 Clermont Ferrand, France, Email: coutand@clermont.inra.fr  
  Corporate Author Thesis  
  Publisher OXFORD UNIV PRESS Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0305-7364 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000274347000025 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 71  
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Author Grangier, J.; Dejean, A.; Male, P.J.G.; Solano, P.J.; Orivel, J. openurl 
  Title (down) Mechanisms driving the specificity of a myrmecophyte-ant association Type Journal Article
  Year 2009 Publication Biological Journal of the Linnean Society Abbreviated Journal Biol. J. Linnean Soc.  
  Volume 97 Issue 1 Pages 90-97  
  Keywords Allomerus decemarticulatus; exclusion filters; Hirtella physophora; horizontal transmission; host recognition; mutualism  
  Abstract In the understory of pristine Guianese forests, the myrmecophyte Hirtella physophora almost exclusively shelters colonies of the plant-ant Allomerus decemarticulatus in its leaf pouches. We experimentally tested three non-mutually exclusive hypotheses concerning phenomena that can determine the species specificity of this association throughout the foundation stage of the colonies: (1) interspecific competition results in the overwhelming presence of A. decemarticulatus queens or incipient colonies; (2) exclusion filters prevent other ant species from entering the leaf pouches; and (3) host-recognition influences the choice of founding queens, especially A. decemarticulatus. Neither interspecific competition, nor the purported exclusion filters that we examined play a major role in maintaining the specificity of this association. Unexpectedly, the plant trichomes lining the domatia appear to serve as construction material during claustral foundation rather than as a filter. Finally, A. decemarticulatus queens are able to identify their host plant from a distance through chemical and/or visual cues, which is rarely demonstrated in studies on obligatory ant-plant associations. We discuss the possibility that this specific host-recognition ability could participate in shaping a compartmentalized plant-ant community where direct competition between ant symbionts is limited. (C) 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 97, 90-97.  
  Address [Grangier, Julien; Male, Pierre-Jean G.; Orivel, Jerome] Univ Toulouse 3, Lab Evolut & Divers Biol, CNRS, UMR 5174, F-31062 Toulouse 9, France, Email: grangier@cict.fr  
  Corporate Author Thesis  
  Publisher WILEY-BLACKWELL PUBLISHING, INC Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0024-4066 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000265406800008 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 114  
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Author Lehnebach, R.; Doumerc, L.; Clair, B.; Alméras, T. url  doi
openurl 
  Title (down) Mechanical stress in the inner bark of 15 tropical tree species and the relationship with anatomical structure Type Journal Article
  Year 2020 Publication Botany Abbreviated Journal Bot.  
  Volume 98 Issue 1 Pages 1-8  
  Keywords Bark anatomical structure; Mechanical stress; Sclereids; Secondary phloem; Tree biomechanics; Tropical species  
  Abstract Recent studies have shown that the inner bark is implicated in the postural control of inclined tree stems through the interaction between wood radial growth and tangential expansion of a trellis fiber network in bark. Assessing the taxonomic extent of this mechanism requires a screening of the diversity in bark anatomy and mechanical stress. The mechanical state of bark was measured in 15 tropical tree species from various botanical families on vertical mature trees, and related to the anatomical structure of the bark. Significant tensile or compressive longitudinal stresses were observed in the stems of most species. Tensile longitudinal stress was observed in various botanical families and was always associated with fibers arranged in a trellis-like structure and strong dilatation of rays. The highest tensile stress was recorded in species with gelatinous fibers forming a treillis. Compressive stress was typically associated with a large amount of sclereids in the bark, supporting the differentiation of sclereids as a potential origin of the generation of longitudinal compressive stresses in bark. In species exhibiting both a fibrous trellis structure and a significant amount of sclereids, the sign of longitudinal stress may depend on the balance between these two mechanisms.  
  Address Faculty of Bioscience Engineering, Laboratory of Wood Technology, Woodlab, Coupure Links 653, Gent, B-9000, Belgium  
  Corporate Author Thesis  
  Publisher Canadian Science Publishing Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 19162804 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Cited By :1; Export Date: 20 January 2020; Correspondence Address: Lehnebach, R.; Laboratoire de Mécanique et Génie Civil (LMGC), Université de Montpellier, CNRS, 860 rue de St. Priest, France; email: lehnebach.romain@hotmail.fr Approved no  
  Call Number EcoFoG @ webmaster @ Serial 913  
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Author Coutand, C.; Dupraz, C.; Jaouen, G.; Ploquin, S.; Adam, B. openurl 
  Title (down) Mechanical stimuli regulate the allocation of biomass in trees: Demonstration with young Prunus avium trees Type Journal Article
  Year 2008 Publication Annals of Botany Abbreviated Journal Ann. Bot.  
  Volume 101 Issue 9 Pages 1421-1432  
  Keywords Prunus avium; growth; mechanical stress; bending; biomass; shoot/root ratio; wind; shelter  
  Abstract Background and Aims Plastic tree-shelters are increasingly used to protect tree seedlings against browsing animals and herbicide drifts. The biomass allocation in young seedlings of deciduous trees is highly disturbed by common plastic tree-shelters, resulting in poor root systems and reduced diameter growth of the trunk. The shelters have been improved by creating chimney-effect ventilation with holes drilled at the bottom, resulting in stimulated trunk diameter growth, but the root deficit has remained unchanged. An experiment was set up to elucidate the mechanisms behind the poor root growth of sheltered Prunus avium trees. Methods Tree seedlings were grown either in natural windy conditions or in tree-shelters. Mechanical wind stimuli were suppressed in ten unsheltered trees by staking. Mechanical stimuli (bending) of the stem were applied in ten sheltered trees using an original mechanical device. Key Results Sheltered trees suffered from poor root growth, but sheltered bent trees largely recovered, showing that mechano-sensing is an important mechanism governing C allocation and the shoot-root balance. The use of a few artificial mechanical stimuli increased the biomass allocation towards the roots, as did natural wind sway. It was demonstrated that there was an acclimation of plants to the imposed strain. Conclusions This study suggests that if mechanical stimuli are used to control plant growth, they should be applied at low frequency in order to be most effective. The impact on the functional equilibrium hypothesis that is used in many tree growth models is discussed. The consequence of the lack of mechanical stimuli should be incorporated in tree growth models when applied to environments protected from the wind (e.g. greenhouses, dense forests).  
  Address [Coutand, Catherine; Jaouen, Gaelle; Ploquin, Stephane; Adam, Boris] Univ Clermont Ferrand, INRA, UMR PIAF, F-63100 Clermont Ferrand, France, Email: coutand@clermont.inra.fr  
  Corporate Author Thesis  
  Publisher OXFORD UNIV PRESS Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0305-7364 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000255987500013 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 211  
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Author Clair, B.; Ghislain, B.; Prunier, J.; Lehnebach, R.; Beauchene, J.; Alméras, T. pdf  url
doi  openurl
  Title (down) Mechanical contribution of secondary phloem to postural control in trees: the bark side of the force Type Journal Article
  Year 2019 Publication New Phytologist Abbreviated Journal New Phytol  
  Volume 221 Issue 1 Pages 209-217  
  Keywords bark; Malvaceae; maturation stress; secondary phloem; tree biomechanics  
  Abstract Summary To grow straight, plants need a motor system that controls posture by generating forces to offset gravity. This motor function in trees was long thought to be only controlled by internal forces induced in wood. Here we provide evidence that bark is involved in the generation of mechanical stresses in several tree species. Saplings of nine tropical species were grown tilted and staked in a shadehouse and the change in curvature of the stem was measured after releasing from the pole and after removing the bark. This first experiment evidenced the contribution of bark in the up-righting movement of tree stems. Combined mechanical measurements of released strains on adult trees and microstructural observations in both transverse and longitudinal/tangential plane enabled us to identify the mechanism responsible for the development of asymmetric mechanical stress in the bark of stems of these species. This mechanism does not result from cell wall maturation like in wood, or from the direct action of turgor pressure like in unlignified organs, but is the consequence of the interaction between wood radial pressure and a smartly organized trellis structure in the inner bark.  
  Address  
  Corporate Author Thesis  
  Publisher John Wiley & Sons, Ltd (10.1111) Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0028-646x ISBN Medium  
  Area Expedition Conference  
  Notes doi: 10.1111/nph.15375 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 853  
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Author Clair, B.; Almeras, T.; Yamamoto, H.; Okuyama, T.; Sugiyama, J. openurl 
  Title (down) Mechanical behavior of cellulose microfibrils in tension wood, in relation with maturation stress generation Type Journal Article
  Year 2006 Publication Biophysical Journal Abbreviated Journal Biophys. J.  
  Volume 91 Issue 3 Pages 1128-1135  
  Keywords  
  Abstract A change in cellulose lattice spacing can be detected during the release of wood maturation stress by synchrotron x-ray diffraction experiment. The lattice strain was found to be the same order of magnitude as the macroscopic strain. The fiber repeat distance, 1.033 nm evaluated for tension wood after the release of maturation stress was equal to the conventional wood values, whereas the value before stress release was larger, corresponding to a fiber repeat of 1.035 nm, nearly equal to that of cotton and ramie. Interestingly, the fiber repeat varied from 1.033 nm for wood to 1.040 nm for algal cellulose, with an increasing order of lateral size of cellulose microfibrils so far reported. These lines of experiments demonstrate that, before the stress release, the cellulose was in a state of tension, which is, to our knowledge, the first experimental evidence supporting the assumption that tension is induced in cellulose microfibrils.  
  Address Kyoto Univ, Res Inst Sustainable Humanosphere, Uji, Kyoto, Japan, Email: sugiyama@rish.kyoto-u.ac.jp  
  Corporate Author Thesis  
  Publisher BIOPHYSICAL SOCIETY Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0006-3495 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000239086800039 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 224  
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Author Almeras, T. openurl 
  Title (down) Mechanical analysis of the strains generated by water tension in plant stems. Part II: strains in wood and bark and apparent compliance Type Journal Article
  Year 2008 Publication Tree Physiology Abbreviated Journal Tree Physiol.  
  Volume 28 Issue 10 Pages 1513-1523  
  Keywords biomechanics; calibration; diurnal strains; mechanical model; multilayer cylinder; water potential  
  Abstract Tree steins shrink in diameter during the day and swell during the night in response to changes in water tension in the xylem. Stein shrinkage can easily be measured in a nondestructive way, to derive continuous information about tree water status. The relationship between the strain and the change in water tension can be evaluated by empirical calibrations, or can be related to the structure of the plant. A mechanical analysis was performed to make this relationship explicit. The stem is modeled as a cylinder made of multiple layers of tissues, including heartwood, sapwood, and inner and outer bark. The effect of changes in water tension on the apparent strain at the surface of a tissue is quantified as a function of parameters defining stem anatomy and the mechanical properties of the tissues. Various possible applications in the context of tree physiology are suggested.  
  Address INRA UMR Ecofog, Kourou 97379, French Guiana, Email: t_almeras@hotmail.com  
  Corporate Author Thesis  
  Publisher HERON PUBLISHING Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0829-318X ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000260027200009 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 129  
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Author Almeras, T.; Gril, J. openurl 
  Title (down) Mechanical analysis of the strains generated by water tension in plant stems. Part 1: stress transmission from the water to the cell walls Type Journal Article
  Year 2007 Publication Tree Physiology Abbreviated Journal Tree Physiol.  
  Volume 27 Issue 11 Pages 1505-1516  
  Keywords biomechanics; cell mechanics; diurnal strains; mechanical model; multilayer cylinder; stress transtnissionjactor  
  Abstract Plant tissues shrink and swell in response to changes in water pressure. These strains can be easily measured, e.g., at the surface of tree stems, to obtain indirect information about plant water status and other physiological parameters. We developed a mechanical model to clarify how water pressure is transmitted to cell walls and causes shrinkage of plant tissues, particularly in the case of thick-walled cells such as wood fibers. Our analysis shows that the stress inside the fiber cell walls is lower than the water tension. The difference is accounted for by a stress transmission factor that depends on two main effects. The first effect is the dilution of the stress through the cell wall, because water acts at the lumen border and is transmitted to the cuter border of the cell, which has a larger circumference. The second effect is the partial conversion of radial stress into tangential stress. Both effects are quantified as functions of parameters of the cell wall structure and its mechanical properties.  
  Address INRA, UMR Ecofog, F-97379 Kourou, French Guiana, France, Email: t_almeras@hotmail.com  
  Corporate Author Thesis  
  Publisher HERON PUBLISHING Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0829-318X ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000250847000001 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 152  
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Author Buckland, S.T.; Yuan, Y.; Marcon, E. pdf  url
doi  openurl
  Title (down) Measuring temporal trends in biodiversity Type Journal Article
  Year 2017 Publication AStA Advances in Statistical Analysis Abbreviated Journal AStA Advances in Statistical Analysis  
  Volume 101 Issue 4 Pages 461-474  
  Keywords Biodiversity measures; Diversity profiles; Geometric mean; Species similarity; Turnover measures  
  Abstract In 2002, nearly 200 nations signed up to the 2010 target of the Convention for Biological Diversity, ‘to significantly reduce the rate of biodiversity loss by 2010’. To assess whether the target was met, it became necessary to quantify temporal trends in measures of diversity. This resulted in a marked shift in focus for biodiversity measurement. We explore the developments in measuring biodiversity that was prompted by the 2010 target. We consider measures based on species proportions, and also explain why a geometric mean of relative abundance estimates was preferred to such measures for assessing progress towards the target. We look at the use of diversity profiles, and consider how species similarity can be incorporated into diversity measures. We also discuss measures of turnover that can be used to quantify shifts in community composition arising, for example, from climate change. © 2017, The Author(s).  
  Address UMR EcoFoG, AgroParisTech, Campus Agronomique, BP 316, Kourou, French Guiana, France  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Cited By :1; Export Date: 2 November 2017 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 769  
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Author Marcon, E.; Puech, F. openurl 
  Title (down) Measures of the geographic concentration of industries: improving distance-based methods Type Journal Article
  Year 2010 Publication Journal of Economic Geography Abbreviated Journal J. Econ. Geogr.  
  Volume 10 Issue 5 Pages 745-762  
  Keywords Geographic concentration; distance-based methods; K-density function; Ripley's K function; M function; C40; C60; R12; L60  
  Abstract We discuss a property of distance-based measures that has not been addressed with regard to evaluating the geographic concentration of economic activities. The article focuses on the choice between a probability density function of point-pair distances or a cumulative function. We begin by introducing a new cumulative function, M, for evaluating the relative geographic concentration and the co-location of industries in a non-homogeneous spatial framework. Secondly, some rigorous comparisons are made with the leading probability density function of Duranton and Overman (2005), Kd. The merits of the simultaneous use of Kd and M is proved, underlining the complementary nature of the results they provide.  
  Address [Marcon, Eric] AgroParisTech ENGREF, UMR EcoFoG, Kourou 97310, French Guiana, Email: Florence.Puech@univ-lyon2.fr  
  Corporate Author Thesis  
  Publisher OXFORD UNIV PRESS Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1468-2702 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000281183300009 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 43  
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