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Author Marcon, E.; Traissac, S.; Puech, F.; Lang, G. pdf  url
openurl 
  Title Tools to characterize point patterns: dbmss for R Type Journal Article
  Year 2015 Publication Journal of Statistical Software Abbreviated Journal Journal of Statistical Software  
  Volume 67 Issue Codesnippet3 Pages 1-15  
  Keywords Point patterns; R; Spatial structure  
  Abstract (up) The dbmss package for R provides an easy-to-use toolbox to characterize the spatial structure of point patterns. Our contribution presents the state of the art of distance-based methods employed in economic geography and which are also used in ecology. Topographic functions such as Ripley’s K, absolute functions such as Duranton and Overman’s Kd and relative functions such as Marcon and Puech’s M are implemented. Their confidence envelopes (including global ones) and tests against counterfactuals are included in the package. © 2015, American Statistical Association. All rights reserved.  
  Address AgroParisTech, INRA, UMR 518 Math. Info. Appli., 16 rue Claude Bernard, Paris, France  
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  Notes Export Date: 22 October 2015 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 635  
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Author Clair, B.; Fournier, M.; Prevost, M.F.; Beauchene, J.; Bardet, S. openurl 
  Title Biomechanics of buttressed trees: Bending strains and stresses Type Journal Article
  Year 2003 Publication American Journal of Botany Abbreviated Journal Am. J. Bot.  
  Volume 90 Issue 9 Pages 1349-1356  
  Keywords biomechanics; buttress; Eleaocarpaceae; French Guiana; Sloanea spp.; tropical trees; wood  
  Abstract (up) The different hypotheses about buttress function and formation mainly involve mechanical theory. Forces were applied to two trees of Sloanea spp.. a tropical genus that develops typical thin buttresses. and the three-dimensional strains were measured at different parts of the trunk base. Risks of failure were greater on the buttress sides, where shear and tangential stresses are greater, not on the ridges. in spite of high longitudinal (parallel to the grain) stresses. A simple beam model, computed from the second moment of area of digitized cross sections, is consistent with longitudinal strain variations but cannot predict accurately variations with height. Patterns of longitudinal strain variation along ridges are very different in the two individuals, owing to a pronounced lateral curvature in one specimen. The constant stress hypothesis is discussed based on these results. Without chronological data during the development of the tree. it cannot be proved that buttress formation is activated by stress or strain.  
  Address CIRAD ENGREF INRA, UMR Ecol Forets Guyane, F-97310 Kourou, Guyane Francais, France  
  Corporate Author Thesis  
  Publisher BOTANICAL SOC AMER INC Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0002-9122 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000185459000010 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 244  
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Author Malé, P.-J.G.; Ferdy, J.-B.; Leroy, C.; Roux, O.; Lauth, J.; Avilez, A.; Dejean, A.; Quilichini, A.; Orivel, J. url  openurl
  Title Retaliation in Response to Castration Promotes a Low Level of Virulence in an Ant-Plant Mutualism Type Journal Article
  Year 2014 Publication Evolutionary Biology Abbreviated Journal Evol. Biol.  
  Volume 41 Issue 1 Pages 22-28  
  Keywords Allomerus decemarticulatus; Cheater; Evolutionary conflict; Hirtella physophora; Mutualism breakdown; Overexploitation  
  Abstract (up) The diversion of a host's energy by a symbiont for its own benefit is a major source of instability in horizontally-transmitted mutualisms. This instability can be counter-balanced by the host's retaliation against exploiters. Such responses are crucial to the maintenance of the relationship. We focus on this issue in an obligate ant-plant mutualism in which the ants are known to partially castrate their host plant. We studied plant responses to various levels of castration in terms of (1) global vegetative investment and (2) investment in myrmecophytic traits. Castration led to a higher plant growth rate, signalling a novel case of gigantism induced by parasitic castration. On the other hand, completely castrated plants produced smaller nesting and food resources (i.e. leaf pouches and extra floral nectaries). Since the number of worker larvae is correlated to the volume of the leaf pouches, such a decrease in the investment in myrmecophytic traits demonstrates for the first time the existence of inducible retaliation mechanisms against too virulent castrating ants. Over time, this mechanism promotes an intermediate level of castration and enhances the stability of the mutualistic relationship by providing the ants with more living space while allowing the plant to reproduce. © 2013 Springer Science+Business Media New York.  
  Address Laboratoire Evolution and Diversité Biologique, Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex 9, France  
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  ISSN 00713260 (Issn) ISBN Medium  
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  Notes Export Date: 10 March 2014; Source: Scopus; Language of Original Document: English; Correspondence Address: Malé, P.-J. G.; Laboratoire Evolution and Diversité Biologique, Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex 9, France; email: pjg.male@gmail.com Approved no  
  Call Number EcoFoG @ webmaster @ Serial 533  
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Author Salas-Lopez, A.; Mickal, H.; Menzel, F.; Orivel, J. doi  openurl
  Title Ant-mediated ecosystem processes are driven by trophic community structure but mainly by the environment Type Journal Article
  Year 2017 Publication Oecologia Abbreviated Journal Oecologia  
  Volume 183 Issue 1 Pages 249-261  
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  Abstract (up) The diversity and functional identity of organisms are known to be relevant to the maintenance of ecosystem processes but can be variable in different environments. Particularly, it is uncertain whether ecosystem processes are driven by complementary effects or by dominant groups of species. We investigated how community structure (i.e., the diversity and relative abundance of biological entities) explains the community-level contribution of Neotropical ant communities to different ecosystem processes in different environments. Ants were attracted with food resources representing six ant-mediated ecosystem processes in four environments: ground and vegetation strata in cropland and forest habitats. The exploitation frequencies of the baits were used to calculate the taxonomic and trophic structures of ant communities and their contribution to ecosystem processes considered individually or in combination (i.e., multifunctionality). We then investigated whether community structure variables could predict ecosystem processes and whether such relationships were affected by the environment. We found that forests presented a greater biodiversity and trophic complementarity and lower dominance than croplands, but this did not affect ecosystem processes. In contrast, trophic complementarity was greater on the ground than on vegetation and was followed by greater resource exploitation levels. Although ant participation in ecosystem processes can be predicted by means of trophic-based indices, we found that variations in community structure and performance in ecosystem processes were best explained by environment. We conclude that determining the extent to which the dominance and complementarity of communities affect ecosystem processes in different environments requires a better understanding of resource availability to different species.  
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  ISSN 1432-1939 ISBN Medium  
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  Call Number EcoFoG @ webmaster @ Salas-Lopez2017 Serial 715  
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Author Houadria, M.; Blüthgen, N.; Salas-Lopez, A.; Schmitt, M.-I.; Arndt, J.; Schneider, E.; Orivel, J.; Menzel, F. url  openurl
  Title The relation between circadian asynchrony, functional redundancy, and trophic performance in tropical ant communities Type Journal Article
  Year 2016 Publication Ecology Abbreviated Journal Ecology  
  Volume 97 Issue 1 Pages 225-235  
  Keywords Diel turnover; Ecosystem functioning; Functional diversity; Multifunctional redundancy; Sampling effect; Temporal partitioning; Tropical rain forests  
  Abstract (up) The diversity-stability relationship has been under intense scrutiny for the past decades, and temporal asynchrony is recognized as an important aspect of ecosystem stability. In contrast to relatively well- studied interannual and seasonal asynchrony, few studies investigate the role of circadian cycles for ecosystem stability. Here, we studied multifunctional redundancy of diurnal and nocturnal ant communities in four tropical rain forest sites. We analyzed how it was influenced by species richness, functional performance, and circadian asynchrony. In two neotropical sites, species richness and functional redundancy were lower at night. In contrast, these parameters did not differ in the two paleotropical sites we studied. Circadian asynchrony between species was pronounced in the neotropical sites, and increased circadian functional redundancy. In general, species richness positively affected functional redundancy, but the effect size depended on the temporal and spatial breadth of the species with highest functional performance. Our analysis shows that high levels of trophic performance were only reached through the presence of such high- performing species, but not by even contributions of multiple, less- efficient species. Thus, these species can increase current functional performance, but reduce overall functional redundancy. Our study highlights that diurnal and nocturnal ecosystem properties of the very same habitat can markedly differ in terms of species richness and functional redundancy. Consequently, like the need to study multiple ecosystem functions, multiple periods of the circadian cycle need to be assessed in order to fully understand the diversity- stability relationship in an ecosystem. © 2016 by the Ecological Society of America.  
  Address CNRS, UMR Ecologie des Forêts de Guyane, BP 709, Kourou Cedex, France  
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  Notes Export Date: 17 February 2016 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 664  
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Author Dezerald, O.; Céréghino, R.; Corbara, B.; Dejean, A.; Leroy, C. url  openurl
  Title Functional trait responses of aquatic macroinvertebrates to simulated drought in a Neotropical bromeliad ecosystem Type Journal Article
  Year 2015 Publication Freshwater Biology Abbreviated Journal Freshwater Biology  
  Volume 60 Issue 9 Pages 1917-1929  
  Keywords Food webs; Precipitations; Rainforests; Resistance/resilience; Tipping point  
  Abstract (up) The duration of the dry seasons in south-eastern Amazonia is expected to increase. Little is known of how freshwater assemblages respond to drought in the humid rainforests and of the extent to which they resist the absence of rainfall before the collapse of the system. We manipulated rainshelters over tank-forming bromeliads (i.e. the interlocking leaf axils of these plants form wells that collect rainwater) to simulate an exceptionally long dry period (49 days, compared with a 10-year mean ± SD annual maximum number of 17 ± 5.3 days without rainfall at the study site) and then a rewetting period. By sampling weekly over 3 months, we followed the dynamics of the representation of abundance-weighted traits in invertebrate assemblages in these treatment plants and in a control group. The functional structure of assemblages was drought resistant until the water volume in the bromeliad pools dropped by 90%, when there was a sudden shift in the functional trait structure due to the loss of most populations except the drought-resistant culicids. Traits related to life history, body size and preferred food showed significant responses to drought. There was a convergence in the functional traits of species surviving in dry plants, strengthening the idea that environmental filtering, rather than stochasticity, determines the functional trajectory of aquatic assemblages during drought. At the end of the dry period, samples of the detritus potentially containing drought-resistant eggs/cysts (and eventually live larvae) were taken from the dry plants and rewetted in the laboratory, allowing us to distinguish resistant species from those requiring recolonisation via subsequent oviposition by adults from elsewhere. Patches of water-filled bromeliads persisting in the area provided the most important pool of colonists, and communities returned to the pre-disturbance state within 1-2 weeks of rewetting. Our results suggest that the functional trait structure of invertebrate assemblages in bromeliads could remain stable under scenarios of precipitation change that would triple the duration of current dry periods at a local scale. Future experiments should evaluate how environmental factors might alter the tipping point between resistance to drought and a collapse in ecosystem processes. © 2015 John Wiley & Sons Ltd.  
  Address IRD, UMR AMAP (botAnique et Modélisation de l'Architecture des Plantes et des vegetations), Boulevard de la Lironde, TA A-51/PS2, Montpellier Cedex 5, France  
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  Notes Export Date: 27 August 2015 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 616  
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Author Mathieu, A.; Letort, V.; Cournède, P.H.; Zhang, B.G.; Heuret, P.; De Reffye, P. url  openurl
  Title Oscillations in functional structural plant growth models Type Journal Article
  Year 2012 Publication Mathematical Modelling of Natural Phenomena Abbreviated Journal  
  Volume 7 Issue 6 Pages 47-66  
  Keywords Cecropia trees; Cucumber plant; Dynamic system of plant growth; Functional-structural plant models; GreenLab  
  Abstract (up) The dynamic model of plant growth GreenLab describes plant architecture and functional growth at the level of individual organs. Structural development is controlled by formal grammars and empirical equations compute the amount of biomass produced by the plant, and its partitioning among the growing organs, such as leaves, stems and fruits. The number of organs initiated at each time step depends on the trophic state of the plant, which is evaluated by the ratio of biomass available in plant to the demand of all the organs. The control of the plant organogenesis by this variable induces oscillations in the simulated plant behaviour. The mathematical framework of the GreenLab model allows to compute the conditions for the generation of oscillations and the value of the period according to the set of parameters. Two case-studies are presented, corresponding to emergence of oscillations associated to fructification and branching. Similar alternating patterns are commonly reported by botanists. In this article, two examples were selected: alternate patterns of fruits in cucumber plants and alternate appearances of branches in Cecropia trees. The model was calibrated from experimental data collected on these plants. It shows that a simple feedback hypothesis of trophic control on plant structure allows the emergence of cyclic patterns corresponding to the observed ones. © EDP Sciences, 2012.  
  Address CIRAD, UMR AMAP, Montpellier, France  
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  Notes Export Date: 27 December 2012; Source: Scopus Approved no  
  Call Number EcoFoG @ webmaster @ Serial 452  
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Author Longo, M.; Knox, R.G.; Levine, N.M.; Swann, A.L.S.; Medvigy, D.M.; Dietze, M.C.; Kim, Y.; Zhang, K.; Bonal, D.; Burban, B.; Camargo, P.B.; Hayek, M.N.; Saleska, S.R.; Da Silva, R.; Bras, R.L.; Wofsy, S.C.; Moorcroft, P.R. pdf  url
doi  openurl
  Title The biophysics, ecology, and biogeochemistry of functionally diverse, vertically and horizontally heterogeneous ecosystems: The Ecosystem Demography model, version 2.2-Part 2: Model evaluation for tropical South America Type Journal Article
  Year 2019 Publication Geoscientific Model Development Abbreviated Journal Geoscientific Model Dev.  
  Volume 12 Issue 10 Pages 4347-4374  
  Keywords  
  Abstract (up) The Ecosystem Demography model version 2.2 (ED-2.2) is a terrestrial biosphere model that simulates the biophysical, ecological, and biogeochemical dynamics of vertically and horizontally heterogeneous terrestrial ecosystems. In a companion paper (Longo et al., 2019a), we described how the model solves the energy, water, and carbon cycles, and verified the high degree of conservation of these properties in long-term simulations that include long-term (multi-decadal) vegetation dynamics. Here, we present a detailed assessment of the model's ability to represent multiple processes associated with the biophysical and biogeochemical cycles in Amazon forests. We use multiple measurements from eddy covariance towers, forest inventory plots, and regional remote-sensing products to assess the model's ability to represent biophysical, physiological, and ecological processes at multiple timescales, ranging from subdaily to century long. The ED-2.2 model accurately describes the vertical distribution of light, water fluxes, and the storage of water, energy, and carbon in the canopy air space, the regional distribution of biomass in tropical South America, and the variability of biomass as a function of environmental drivers. In addition, ED-2.2 qualitatively captures several emergent properties of the ecosystem found in observations, specifically observed relationships between aboveground biomass, mortality rates, and wood density; however, the slopes of these relationships were not accurately captured. We also identified several limitations, including the model's tendency to overestimate the magnitude and seasonality of heterotrophic respiration and to overestimate growth rates in a nutrient-poor tropical site. The evaluation presented here highlights the potential of incorporating structural and functional heterogeneity within biomes in Earth system models (ESMs) and to realistically represent their impacts on energy, water, and carbon cycles. We also identify several priorities for further model development.  
  Address Georgia Institute of Technology, Atlanta, GA, United States  
  Corporate Author Thesis  
  Publisher Copernicus GmbH Place of Publication Editor  
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  ISSN 1991959x (Issn) ISBN Medium  
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  Notes Cited By :1; Export Date: 27 October 2019; Correspondence Address: Longo, M.; Harvard UniversityUnited States; email: mdplongo@gmail.com Approved no  
  Call Number EcoFoG @ webmaster @ Serial 890  
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Author Lecante, A.; Robert, F.; Blandinieres, P.A.; Roos, C. openurl 
  Title Anti-corrosive properties of S. tinctoria and G. ouregou alkaloid extracts on low carbon steel Type Journal Article
  Year 2011 Publication Current Applied Physics Abbreviated Journal Curr. Appl. Phys.  
  Volume 11 Issue 3 Pages 714-724  
  Keywords Low carbon steel; Acidic media; Corrosion inhibitor; Plant extract; EIS  
  Abstract (up) The effect of alkaloid extracts from two Amazonian trees (Guatteria ouregou and Simira tinctoria) on low carbon steel corrosion was investigated in acidic solutions by using electrochemical techniques. All of these plant extracts inhibit the corrosion of low carbon steel in 0.1 M HCl solutions. As their concentration increases to 250 mg/L, the inhibition efficiencies of S. tinctoria and G. ouregou alkaloid extracts reach approximately 92% in 0.1 M HCl solutions. The adsorption of the inhibitor molecules was in accordance with the Langmuir adsorption isotherm. The results obtained show that these plant extracts could be serve as an effective inhibitor for the corrosion of low carbon steel in hydrochloric acid media. Furthermore, harmane was identified as the main component of S. tinctoria extract and that suggests that it is the active ingredient against corrosion of low carbon steel. (C) 2010 Elsevier B.V. All rights reserved.  
  Address [Lecante, A.; Robert, F.; Blandinieres, P. A.; Roos, C.] UAG UMR ECOFOG, Lab Mat & Mol Milieu Amazonien, F-97337 Cayenne, French Guiana, France, Email: florent.robert@guyane.univ-ag.fr  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1567-1739 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000288183300088 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 300  
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Author Lebrini, M.; Robert, F.; Blandinieres, P.A.; Roos, C. pdf  openurl
  Title Corrosion Inhibition by Isertia coccinea Plant Extract in Hydrochloric Acid Solution Type Journal Article
  Year 2011 Publication International Journal of Electrochemical Science Abbreviated Journal Int. J. Electrochem. Sci.  
  Volume 6 Issue 7 Pages 2443-2460  
  Keywords Isertia coccinea; corrosion inhibitors; C38 steel; acidic media; adsorption  
  Abstract (up) The effect of alkaloids extracted from Isertia coccinea plant (AEIC) on the corrosion of C38 steel in 1 M hydrochloric acid was investigated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. Potentiodynamic polarization curves indicated that the extract behave as mixed-type inhibitor. The experimental data obtained from EIS method show a frequency distribution and therefore a modelling element with frequency dispersion behaviour, a constant phase element (CPE) has been used. The inhibition efficiencies of the extract calculated by three methods show the same tendency. Inhibition was found to increase with increasing concentration of the plant extract. The results obtained show that the extract solution of the plant could serve as an effective inhibitor for the corrosion of C38 steel in hydrochloric acid solution. The apparent activation energy of the process taking place in inhibitor presence was determined on the ground of four temperature values in the range from 25 degrees C to 55 degrees C using the data obtained by two independent methods. Theoretical fitting of different isotherms, Langmuir, Temkin and Frunkin, were tested to clarify the nature of adsorption.  
  Address [Lebrini, M.; Robert, F.; Blandinieres, P. A.; Roos, C.] UAG UMR ECOFOG, Lab Mat & Mol Milieu Amazonien, Cayenne 97337, French Guiana, Email: florent.robert@guyane.univ-ag.fr  
  Corporate Author Thesis  
  Publisher Electrochemical Science Group Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1452-3981 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000292331400014 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 324  
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