toggle visibility Search & Display Options

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Rahali, H.; Ghanem, N.; Griffe, L.; Rahali, R.; Stien, D. openurl 
  Title A general approach to the quantification of resin-bound functional groups by NMR Type Journal Article
  Year 2004 Publication New Journal of Chemistry Abbreviated Journal New J. Chem.  
  Volume 28 Issue 11 Pages 1344-1346  
  Keywords  
  Abstract There has been a continuing need for sensitive, accurate and rapid methods to monitor functional loading of insoluble supports for solid phase synthesis. The present articles reports our findings regarding functional group loading quantification using H-1 NMR. Results obtained for supported amino, hydroxyl and NH-Fmoc groups are in agreement with those calculated using well-established methods and demonstrate that the strategy of looking, either at the excess reagent left in solution (NH2 and OH), or at the protecting group derivatives released from the polymer (Fmoc), is a viable approach to resin loading quanti. cation.  
  Address (down) Univ Montpellier 2, CNRS, UMR 5810, Lab Aminoacides Peptides & Prot, F-34095 Montpellier 05, France, Email: didier.stien@guyane.cnrs.fr  
  Corporate Author Thesis  
  Publisher ROYAL SOC CHEMISTRY Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1144-0546 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000224894700013 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 261  
Permanent link to this record
 

 
Author Clair, B.; Arinero, R.; Leveque, G.; Ramonda, M.; Thibaut, B. openurl 
  Title Imaging the mechanical properties of wood cell wall layers by atomic force modulation microscopy Type Journal Article
  Year 2003 Publication IAWA Journal Abbreviated Journal IAWA J.  
  Volume 24 Issue 3 Pages 223-230  
  Keywords wood; cell wall; mechanical properties; elastic modulus; tension wood  
  Abstract Atomic Force Microscopy in force modulation mode was used to study the elastic properties of the different fibre wall layers of the tension wood of holm oak and normal wood of boco. The method is based on the measurement of the resonance frequency of the microscope lever in contact with the sample. This frequency is related to the reduced Young modulus E* = E/(1-nu(2)) of the material, supposed to be isotropic. 'Elastic' images of the cell are obtained simultaneously with the topographic images, which allows the observation of the mechanical properties of the cells at a nanometric scale. Layers G, S-1, S-2 and ML can clearly be distinguished. By comparison with known materials an estimation of the absolute modulus is given in the range 5-20 GPa, but should be considered with caution, because the inherent anisotropy of the materials has not been taken into account.  
  Address (down) Univ Montpellier 2, CNRS, UMR 5508, Lab Mecan & Genie Civil, F-34095 Montpellier, France  
  Corporate Author Thesis  
  Publisher INT ASSOC WOOD ANATOMISTS Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0928-1541 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000185049700003 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 270  
Permanent link to this record
 

 
Author Baraloto, C.; Bonal, D.; Goldberg, D.E. openurl 
  Title Differential seedling growth response to soil resource availability among nine neotropical tree species Type Journal Article
  Year 2006 Publication Journal of Tropical Ecology Abbreviated Journal J. Trop. Ecol.  
  Volume 22 Issue Pages 487-497  
  Keywords biomass allocation; Dicorynia; drought stress; Eperua; French Guiana; Goupia; Jacaranda; plasticity; Qualea; Recordorylon; relative growth rate; Sextonia; soil phosphorus; specific leaf area; Virola  
  Abstract Although the potential contribution to tropical tree species coexistence of niche differentiation along light gradients has received much attention, the degree to which species perform differentially along soil resource gradients remains unclear. To examine differential growth response to soil resources, we grew seedlings of nine tropical tree species at 6.0% of full sun for 12 mo in a factorial design of two soil types (clay and white sand), two phosphate fertilization treatments (control and addition of 100 mg P kg(-1)) and two watering treatments (field capacity and water limitation to one-third field capacity). Species differed markedly in biomass growth rate, but this hierarchy was almost completely conserved across all eight treatments. All species grew more slowly in sand than clay soils. and no species grew faster with phosphate additions. Only Eperua grandiflora and E. falcata showed significant growth increases in the absence of water limitation. Faster-growing species were characterized by high specific leaf area, high leaf allocation and high net assimilation rate but not lower root allocation. Slower-growing species exhibited greater plasticity in net assimilation rate. suggesting that tolerance of edaphic stress in these species is related more to stomatal control than to whole-plant carbon allocation. Although relative growth rate for biomass was correlated with both its physiological and morphological components. interspecific differences were best explained by differences in net assimilation rate across six of the eight treatments. A suite of traits including high assimilation and high specific leaf area maintains rapid growth rate of faster-growing species across a wide gradient of soil resources, but the lack of plasticity they exhibit may compromise their survival in the poorest soil environments.  
  Address (down) Univ Michigan, Dept Ecol & Evolutionary Biol, Ann Arbor, MI 48109 USA, Email: baraloto.c@kourou.cirad.fr  
  Corporate Author Thesis  
  Publisher CAMBRIDGE UNIV PRESS Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0266-4674 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000239975200001 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 178  
Permanent link to this record
 

 
Author Baraloto, C.; Goldberg, D.E.; Bonal, D. openurl 
  Title Performance trade-offs among tropical tree seedlings in contrasting microhabitats Type Journal Article
  Year 2005 Publication Ecology Abbreviated Journal Ecology  
  Volume 86 Issue 9 Pages 2461-2472  
  Keywords canopy gaps; French Guiana; regeneration niche; relative growth rate; seed size; shade tolerance; soil moisture; tropical forest  
  Abstract We investigated performance trade-offs among seedlings of nine tropical tree species during a -five-year field experiment. Seedlings were grown in eight microhabitat types composed of paired gap and shaded understory sites in each of four soil types. We defined performance trade-offs relevant to coexistence as significant pairwise rank reversals for species performance between contrasting situations, of which we characterize three types: microhabitat, fitness component, and ontogenetic. Only 2 of 36 species pairs exhibited microhabitat trade-offs or reversed rankings for survival or relative growth rate (RGR) among microhabitats, and only one species pair reversed performance ranks among soil types. We found stronger evidence for rank reversals between fitness components (survival and RGR), particularly in gap vs. understory environments, suggesting a general trade-off between shade tolerance (survival in shade) and gap establishment (RGR in gaps). Third, the most frequent rank reversals between species pairs occurred between early and later ontogenetic stages, especially between fitness components in contrasting microhabitats. Overall, 15 of 36 pairs of potentially competing species exhibited some type of seedling performance trade-off, two species pairs never outperformed one another, and for 19 species pairs one species was a consistent better performer. We suggest that ontogenetic trade-offs, in concert with microhabitat and fitness component trade-offs, may contribute to species coexistence of long-lived organisms such as tropical trees.  
  Address (down) Univ Michigan, Dept Ecol & Evolutionary Biol, Ann Arbor, MI 48109 USA, Email: baraloto.c@kourou.cirad.fr  
  Corporate Author Thesis  
  Publisher ECOLOGICAL SOC AMER Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0012-9658 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000231373600021 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 252  
Permanent link to this record
 

 
Author Christensen-Dalsgaard, K.K.; Fournier, M.; Ennos, A.R.; Barfod, A.S. openurl 
  Title Changes in vessel anatomy in response to mechanical loading in six species of tropical trees Type Journal Article
  Year 2007 Publication New Phytologist Abbreviated Journal New Phytol.  
  Volume 176 Issue 3 Pages 610-622  
  Keywords hydraulic architecture; hydraulic-mechanical trade-off; mechanical adaptation; rooting morphology; tropical trees; vascular anatomy  
  Abstract It is well known that trees adapt their supportive tissues to changes in loading conditions, yet little is known about how the vascular anatomy is modified in this process. We investigated this by comparing more and less mechanically loaded sections in six species of tropical trees with two different rooting morphologies. We measured the strain, vessel size, frequency and area fraction and from this calculated the specific conductivity, then measured the conductivity, modulus of elasticity and yield stress. The smallest vessels and the lowest vessel frequency were found in the parts of the trees subjected to the greatest stresses or strains. The specific conductivity varied up to two orders of magnitude between mechanically loaded and mechanically unimportant parts of the root system. A trade-off between conductivity and stiffness or strength was revealed, which suggests that anatomical alterations occur in response to mechanical strain. By contrast, between-tree comparisons showed that average anatomical features for the whole tree seemed more closely related to their ecological strategy.  
  Address (down) Univ Manchester, Fac Life Sci, Manchester M60 1QD, Lancs, England, Email: karen@cd-mail.dk  
  Corporate Author Thesis  
  Publisher BLACKWELL PUBLISHING 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 ISI:000250275000013 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 156  
Permanent link to this record
 

 
Author Maron, P.A.; Schimann, H.; Ranjard, L.; Brothier, E.; Domenach, A.M.; Lensi, R.; Nazaret, S. openurl 
  Title Evaluation of quantitative and qualitative recovery of bacterial communities from different soil types by density gradient centrifugation Type Journal Article
  Year 2006 Publication European Journal of Soil Biology Abbreviated Journal Eur. J. Soil Biol.  
  Volume 42 Issue 2 Pages 65-73  
  Keywords bacterial community; soil; density gradient; DNA fingerprint  
  Abstract Extracting and purifying a representative fraction of bacteria from soil is necessary for the application of many techniques of microbial ecology. Here the influence of different soil types on the quantitative and qualitative recovery of bacteria by soil grinding and Nycodenz density gradient centrifugation was investigated. Three soils presenting contrasted physicochemical characteristics were used for this study. For each soil, the total (AODC: acridine orange direct count) and culturable (cfa: colony-forming units) bacterial densities were measured in three distinct fractions: (i) the primary soil, (ii) the soil pellet (soil remaining after centrifugation), and (iii) the extracted cells. The automated-ribosomal intergenic spacer analysis (A-RISA) was used to characterize the community structure directly from the DNA extracted from each fraction. The physicochemical characteristics of soils were found to influence both the efficiency of bacterial cell recovery and the representativeness of the extracted cells in term of community structures between the different fractions. Surprisingly, the most representative extracted cells were obtained from the soil exhibiting the lowest efficiency of cell recovery. Our results demonstrated that quantitative and qualitative cell recovery using Nycodenz density gradient centrifugation are not necessarily related and could be differentially biased according to soil type. (c) 2006 Elsevier SAS. All rights reserved.  
  Address (down) Univ Lyon 1, CNRS, UMR 5557, Ctr Microbial Ecol, F-69622 Villeurbanne, France, Email: nazaret@biomserv.univ-lyon1.fr  
  Corporate Author Thesis  
  Publisher ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1164-5563 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000238534500001 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 181  
Permanent link to this record
 

 
Author Herault, B.; Honnay, O. openurl 
  Title Using life-history traits to achieve a functional classification of habitats Type Journal Article
  Year 2007 Publication Applied Vegetation Science Abbreviated Journal Appl. Veg. Sci.  
  Volume 10 Issue 1 Pages 73-80  
  Keywords forest connectivity; functional group; habitat typology; land-use history; riverine forest; species functional unity  
  Abstract Question: To establish a habitat classification based on functional group co-occurrence that may help the drawing up of conservation plans. Location: Riverine forest fragments in the Grand-duche de Luxembourg, Europe. Methods: Forest fragments were surveyed for their abundance of vascular plants. These were clustered into emergent groups according to 14 life-traits related to plant dispersal, establishment and persistence. Forest fragments were classified according to similar distribution of the identified emergent groups. Environmental factors were related to the emergent group richness in each forest type using generalized linear models. Results: Contrary to former species centred classifications, only two groups of forests, each with clearly different emergent group composition and conservation requirements, were detected: (1) swamp forests characterized by anemogamous perennials, annuals and hydrochorous perennials and (2) moist forests characterized by barochorous perennials, small geophytes and zoochorous phanerophytes. From a conservation point of view, priority should be given to large swamp forest with intact flooding regimes. This is in accordance with the high wind and water dispersal capacities of their typical emergent groups. For the moist forests, conservation priorities should be high forest connectivity and historical continuity since dispersal and establishment of their characteristic emergent groups are highly limited. Conclusions: The described methodology, situated at an intermediate integration level between the individual species and whole community descriptors, takes advantage of both conservation plans built for single species and the synthetic power of broad ecological measures.  
  Address (down) Univ Liege, Dept Environm Sci & Management, B-6700 Arlon, Belgium, Email: bruno.herault@cirad.fr  
  Corporate Author Thesis  
  Publisher OPULUS PRESS UPPSALA AB Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1402-2001 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000245934700009 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 218  
Permanent link to this record
 

 
Author Hardy, O.J.; Maggia, L.; Bandou, E.; Breyne, P.; Caron, H.; Chevallier, M.H.; Doligez, A.; Dutech, C.; Kremer, A.; Latouche-Halle, C.; Troispoux, V.; Veron, V.; Degen, B. openurl 
  Title Fine-scale genetic structure and gene dispersal inferences in 10 Neotropical tree species Type Journal Article
  Year 2006 Publication Molecular Ecology Abbreviated Journal Mol. Ecol.  
  Volume 15 Issue 2 Pages 559-571  
  Keywords French Guiana; gene dispersal; seed dispersal; spatial genetic structure; tropical trees  
  Abstract The extent of gene dispersal is a fundamental factor of the population and evolutionary dynamics of tropical tree species, but directly monitoring seed and pollen movement is a difficult task. However, indirect estimates of historical gene dispersal can be obtained from the fine-scale spatial genetic structure of populations at drift-dispersal equilibrium. Using an approach that is based on the slope of the regression of pairwise kinship coefficients on spatial distance and estimates of the effective population density, we compare indirect gene dispersal estimates of sympatric populations of 10 tropical tree species. We re-analysed 26 data sets consisting of mapped allozyme, SSR (simple sequence repeat), RAPD (random amplified polymorphic DNA) or AFLP (amplified fragment length polymorphism) genotypes from two rainforest sites in French Guiana. Gene dispersal estimates were obtained for at least one marker in each species, although the estimation procedure failed under insufficient marker polymorphism, limited sample size, or inappropriate sampling area. Estimates generally suffered low precision and were affected by assumptions regarding the effective population density. Averaging estimates over data sets, the extent of gene dispersal ranged from 150 m to 1200 m according to species. Smaller gene dispersal estimates were obtained in species with heavy diaspores, which are presumably not well dispersed, and in populations with high local adult density. We suggest that limited seed dispersal could indirectly limit effective pollen dispersal by creating higher local tree densities, thereby increasing the positive correlation between pollen and seed dispersal distances. We discuss the potential and limitations of our indirect estimation procedure and suggest guidelines for future studies.  
  Address (down) Univ Libre Bruxelles, Serv Ecoethol Evolut, B-1050 Brussels, Belgium, Email: ohardy@ulb.ac.be  
  Corporate Author Thesis  
  Publisher BLACKWELL PUBLISHING Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0962-1083 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000235045500021 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 183  
Permanent link to this record
 

 
Author Ponton, S.; Flanagan, L.B.; Alstad, K.P.; Johnson, B.G.; Morgenstern, K.; Kljun, N.; Black, T.A.; Barr, A.G. openurl 
  Title Comparison of ecosystem water-use efficiency among Douglas-fir forest, aspen forest and grassland using eddy covariance and carbon isotope techniques Type Journal Article
  Year 2006 Publication Global Change Biology Abbreviated Journal Glob. Change Biol.  
  Volume 12 Issue 2 Pages 294-310  
  Keywords boreal forest; conifer forest; eddy covariance; grassland; stable isotopes  
  Abstract Comparisons were made among Douglas-fir forest, aspen (broad leaf deciduous) forest and wheatgrass (C-3) grassland for ecosystem-level water-use efficiency (WUE). WUE was defined as the ratio of photosynthetic CO2 assimilation rate and evapotranspiration (ET) rate. The ET data measured by eddy covariance were screened so that they overwhelmingly represented transpiration. The three sites used in this comparison spanned a range of vegetation (plant functional) types and environmental conditions within western Canada. When compared in the relative order Douglas-fir (located on Vancouver Island, BC), aspen (northern Saskatchewan), grassland (southern Alberta), the sites demonstrated a progressive decline in precipitation and a general increase in maximum air temperature and atmospheric saturation deficit (D-max) during the mid-summer. The average (+/- SD) WUE at the grassland site was 2.6 +/- 0.7 mmol mol(-1), which was much lower than the average values observed for the two other sites (aspen: 5.4 +/- 2.3, Douglas-fir: 8.1 +/- 2.4). The differences in WUE among sites were primarily because of variation in ET. The highest maximum ET rates were approximately 5, 3.2 and 2.7 mm day(-1) for the grassland, aspen and Douglas-fir sites, respectively. There was a strong negative correlation between WUE and D-max for all sites. We also made seasonal measurements of the carbon isotope ratio of ecosystem respired CO2 (delta(R)) in order to test for the expected correlation between shifts in environmental conditions and changes to the ecosystem-integrated ratio of leaf intercellular to ambient CO2 concentration (c(i)/c(a)). There was a consistent increase in delta(R) values in the grassland, aspen forest and Douglas-fir forest associated with a seasonal reduction in soil moisture. Comparisons were made between WUE measured using eddy covariance with that calculated based on D and delta(R) measurements. There was excellent agreement between WUE values calculated using the two techniques. Our delta(R) measurements indicated that c(i)/c(a) values were quite similar among the Douglas-fir, aspen and grassland sites, despite large variation in environmental conditions among sites. This implied that the shorter-lived grass species had relatively high c(i)/c(a) values for the D of their habitat. By contrast, the longer-lived Douglas-fir trees were more conservative in water-use with lower c(i)/c(a) values relative to their habitat D. This illustrates the interaction between biological and environmental characteristics influencing ecosystem-level WUE. The strong correlation we observed between the two independent measurements of WUE, indicates that the stable isotope composition of respired CO2 is a useful ecosystem-scale tool to help study constraints to photosynthesis and acclimation of ecosystems to environmental stress.  
  Address (down) Univ Lethbridge, Dept Biol Sci, Lethbridge, AB T1K 3M4, Canada, Email: larry.flanagan@uleth.ca  
  Corporate Author Thesis  
  Publisher BLACKWELL PUBLISHING Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1354-1013 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000234974900013 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 226  
Permanent link to this record
 

 
Author Koponen, P.; Nygren, P.; Domenach, A.M.; Le Roux, C.; Saur, E.; Roggy, J.C. openurl 
  Title Nodulation and dinitrogen fixation of legume trees in a tropical freshwater swamp forest in French Guiana Type Journal Article
  Year 2003 Publication Journal of Tropical Ecology Abbreviated Journal J. Trop. Ecol.  
  Volume 19 Issue Pages 655-666  
  Keywords acetylene reduction assay; Bradyrhizobium; flooding; microtopography; N-15 natural abundance method; 16S rDNA sequencing  
  Abstract Nodulated legume trees comprised 43% of the stand basal area in the low, most frequently flooded microsites, and 23% in higher, drier microsites in a tropical freshwater swamp forest in French Guiana. Dinitrogen fixation in Pterocarpus officinalis, Hydrochorea corymbosa and Inga pilosula was confirmed by acetylene reduction assay (ARA), presence of leghaemoglobin in nodules and the N-15 natural abundance method. The results for Zygia cataractae were inconclusive but suggested N-2 fixation in drier microsites. Nodulated Inga disticha had a N-15-to-N-14 ratio similar to non-N-2-fixing trees, but ARA indicated nitrogenase activity and leghaemoglobin was present in nodules. All bacterial strains were identified as Bradyrhizobium spp. according to the partial 16S rDNA sequences, and they were infective in vitro in the model species Macroptilium atropurpuretan. About 35-50% of N in the leaves of P. officinalis, H. corymbosa and I. pilosula was fixed from the atmosphere. Dinitrogen fixation was estimated to contribute at least 8-13% and 1728% to whole-canopy N in high and low microsites, respectively. Symbiotic N, fixation appears to provide both a competitive advantage to legume trees under N-limited, flooded conditions and an important N input to neotropical freshwater swamp forests.  
  Address (down) Univ Helsinki, Dept Forest Ecol, FIN-00014 Helsinki, Finland  
  Corporate Author Thesis  
  Publisher CAMBRIDGE UNIV PRESS Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0266-4674 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000186710800005 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 242  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations:
Export Records: