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| Author |
Guitet, S.; Sabatier, D.; Brunaux, O.; Couteron, P.; Denis, T.; Freycon, V.; Gonzalez, S.; Hérault, B.; Jaouen, G.; Molino, J.-F.; Pélissier, R.; Richard-Hansen, C.; Vincent, G. |
| Title |
Disturbance Regimes Drive the Diversity of Regional Floristic Pools Across Guianan Rainforest Landscapes |
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Journal Article |
| Year |
2018 |
Publication |
Scientific Reports |
Abbreviated Journal |
Sci. Rep. |
| Volume |
8 |
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3872 |
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Disturbances control rainforest dynamics, and, according to the intermediate disturbance hypothesis (IDH), disturbance regime is a key driver of local diversity. Variations in disturbance regimes and their consequences on regional diversity at broad spatiotemporal scales are still poorly understood. Using multidisciplinary large-scale inventories and LiDAR acquisitions, we developed a robust indicator of disturbance regimes based on the frequency of a few early successional and widely distributed pioneer species. We demonstrate at the landscape scale that tree-species diversity and disturbance regimes vary with climate and relief. Significant relationships between the disturbance indicator, tree-species diversity and soil phosphorus content agree with the hypothesis that rainforest diversity is controlled both by disturbance regimes and long-term ecosystem stability. These effects explain the broad-scale patterns of floristic diversity observed between landscapes. In fact, species-rich forests in highlands, which have benefited from long-term stability combined with a moderate and regular regime of local disturbances, contrast with less diversified forests on recently shaped lowlands, which have undergone more recent changes and irregular dynamics. These results suggest that taking the current disturbance regime into account and including geomorphological stratifications in climate-vegetation models may be an effective way to improve the prediction of changes in species diversity under climate change. © 2018 The Author(s). |
| Address |
AgroParisTech, EcoFoG, Kourou, French Guiana |
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Export Date: 21 March 2018 |
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no |
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EcoFoG @ webmaster @ |
Serial |
798 |
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| Author |
Lebrini, M.; Roos, C.; Vezin, H.; Robert, F. |
| Title |
Electrochemical and theoretical studies of adsorption of some indole derivates at C38 Steel/Sulfuric acid interface as corrosion inhibitors |
Type |
Journal Article |
| Year |
2011 |
Publication |
International Journal of Electrochemical Science |
Abbreviated Journal |
Int.J.Electrochem.Sci. |
| Volume |
6 |
Issue |
9 |
Pages |
3844-3857 |
| Keywords |
Acidic media; Adsorption; C38 steel; Corrosion inhibitors; Theoretical calculations |
| Abstract |
The inhibitive action of 9H-pyrido[3,4-b]indole (norharmane) and 1-Methyl-9H-pyrido[3,4-b]indole (harmane) on corrosion of C38 steel in 0.5 M H2SO4 solution was investigated through electrochemical techniques. The experimental results obtained revealed that these compounds inhibited the steel corrosion in acid solution for all concentrations studied. Polarization measurements indicate that the examined compounds act as a mixed inhibitor and its inhibition efficiency increases with inhibitor concentration. Data obtained from ac impedance technique show a frequency distribution and therefore a modelling element with frequency dispersion behaviour, a constant phase element (CPE), has been used. The adsorption of used compounds on the steel surface obeys Langmuir's isotherm. The ΔG°ads values were calculated and discussed for both inhibitors. Significant correlations are obtained between inhibition efficiency and quantum chemical parameters using quantitative structure-activity relationship (QSAR) method. © 2011 by ESG. |
| Address |
Laboratoire de Chimie Organique et Macromoléculaire, UMR-CNRS 8009, USTL BâtC4, F-59655 Villeneuve d'Ascq Cedex, France |
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14523981 (Issn) |
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Export Date: 21 October 2011; Source: Scopus; Language of Original Document: English; Correspondence Address: Robert, F.; Laboratoire Matériaux et Molécules en Milieu Amazonien, UAG-UMR ECOFOG, Campus Trou Biran, Cayenne 97337, French Guiana; email: florent.robert@guyane.univ-ag.fr |
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EcoFoG @ webmaster @ |
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347 |
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Scotti, I.; Gugerli, F.; Pastorelli, R.; Sebastiani, F.; Vendramin, G.G. |
| Title |
Maternally and paternally inherited molecular markers elucidate population patterns and inferred dispersal processes on a small scale within a subalpine stand of Norway spruce (Picea abies [L.] Karst.) |
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Journal Article |
| Year |
2008 |
Publication |
Forest Ecology and Management |
Abbreviated Journal |
For. Ecol. Manage. |
| Volume |
255 |
Issue |
11 |
Pages |
3806-3812 |
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chloroplast microsatellites; mitochondrial minisatellites; pollen/seed dispersal; demography; spatial autocorrelation |
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The within-population spatial structure of genetic diversity is shaped by demographic processes, including historical accidents such as forest perturbations. Information drawn from the analysis of the spatial distribution of genetic diversity is therefore inherently linked to demographic-historical processes that ultimately determine the fate of populations. All adult trees and saplings in a 1.4-ha plot within a mixed Norway spruce (Picea abies [L.] Karst) stand were characterised by means of chloroplast (paternally inherited) markers, and a large sub-sample of these were genotyped at mitochondrial (maternally inherited) molecular markers. These data were used to analyse the spatial distribution of genetic variation and to compare the patterns corresponding to the two marker types. The plot presented non-homogeneous local stem density in the younger cohorts, and the indirect effect of this source of variation on the spatial genetic structure was investigated. Results suggest that (i) spatially limited seed dispersal induced patchiness in genotype distribution, while pollen flow had a homogenising effect; (ii) deviations from random spatial structure were stronger in the demographically most stable portions of the stand, while they were weaker where sudden bursts of regeneration occurred; (iii) spatially overlapping adult and sapling cohorts displayed the same spatial genetic structure (stronger on stable areas, weaker in portions of the stand undergoing events of intense regeneration), which was substantiated by the influence of local demographic processes. Regeneration dynamics as modulated by demography thus influences the distribution of genetic diversity within the stand both in the younger life stages and in the adult population. (C) 2008 Elsevier B.V. All rights reserved. |
| Address |
[Scotti, I.] INRA, UMR 0745, ECOFOG, F-97387 Kourou, France, Email: ivan.scotti@kourou.cirad.fr |
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ELSEVIER SCIENCE BV |
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0378-1127 |
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ISI:000257019100019 |
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no |
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EcoFoG @ eric.marcon @ |
Serial |
137 |
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Baudrimont, M.; Arini, A.; Guégan, C.; Venel, Z.; Gigault, J.; Pedrono, B.; Prunier, J.; Maurice, L.; Ter Halle, A.; Feurtet-Mazel, A. |
| Title |
Ecotoxicity of polyethylene nanoplastics from the North Atlantic oceanic gyre on freshwater and marine organisms (microalgae and filter-feeding bivalves) |
Type |
Journal Article |
| Year |
2020 |
Publication |
Environmental Science and Pollution Research |
Abbreviated Journal |
Environ. Sci. Pollut. Res. |
| Volume |
27 |
Issue |
4 |
Pages |
3746-3755 |
| Keywords |
Cordicula fluminea; Ecotoxicity; Nanoplastics; Polyethylene; Scenedesmus subspicatus; Thalassiosira weissiflogii; bivalve; concentration (composition); ecotoxicology; filter feeder; gyre; microalga; nanoparticle; plastic waste; pollution exposure; polymer; Atlantic Ocean; Atlantic Ocean (North); Bivalvia; Chlorophyta; Corbicula fluminea; Desmodesmus subspicatus; Nitzschia alba; Thalassiosira |
| Abstract |
Each year, 5 to 10 million tons of plastic waste is dumped in the oceans via freshwaters and accumulated in huge oceanic gyres. Under the effect of several abiotic factors, macro plastic wastes (or plastic wastes with macro sizes) are fractionated into microplastics (MP) and finally reach the nanometric size (nanoplastic NP). To reveal potential toxic impacts of these NPs, two microalgae, Scenedemus subspicatus (freshwater green algae), and Thalassiosira weissiflogii (marine diatom) were exposed for up to 48 h at 1, 10, 100, 1000, and 10,000 μg/L to reference polyethylene NPs (PER) or NPs made from polyethylene collected in the North Atlantic gyre (PEN, 7th continent expedition in 2015). Freshwater filter-feeding bivalves, Corbicula fluminea, were exposed to 1000 μg/L of PER and PEN for 48 h to study a possible modification of their filtration or digestion capacity. The results show that PER and PEN do not influence the cell growth of T. weissiflogii, but the PEN exposure causes growth inhibition of S. subspicatus for all exposure concentrations tested. This growth inhibition is enhanced for a higher concentration of PER or PEN (10,000 μg/L) in S. subspicatus. The marine diatom T. weissiflogii appears to be less impacted by plastic pollution than the green algae S. subspicatus for the exposure time. Exposure to NPs does not lead to any alteration of bivalve filtration; however, fecal and pseudo-fecal production increased after PEN exposure, suggesting the implementation of rejection mechanisms for inedible particles. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature. |
| Address |
UMR IMRCP 5623, Université Paul Sabatier, CNRS, 118, route de Narbonne, Toulouse, 31062, France |
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Springer |
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09441344 (Issn) |
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Cited By :1; Export Date: 23 March 2020; Coden: Esple; Correspondence Address: Baudrimont, M.; UMR EPOC 5805, Université de Bordeaux—CNRS, Place du Dr Peyneau, France; email: magalie.baudrimont@u-bordeaux.fr |
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EcoFoG @ webmaster @ |
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925 |
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Peguero, Guille ; Ferrin, Miquel ; Sardans, Jordi ; Verbruggen, Erik ; Ramirez-Rojas , Irène ; Van Langenhove, Leandro ; Verryckt, Lore T. ; Murienne, Jérôme ; Iribar, Amaia ; Zinger, Lucie ; Grau, Oriol ; Orivel, Jérome ; Stahl, Clement ; Courtois, Elodie A. ; Asensio, Dolores ; Gargallo-Garriga, Albert ; Llusia, Joan ; Margalef, Olga ; Ogaya, Roma ; Richter, Andreas ; Janssens, Ivan A. ; Penuelas, Josep |
| Title |
Decay of similitary across tropical forest communities: integrating spatial distance with soil nutrients |
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Journal Article |
| Year |
2021 |
Publication |
Ecology |
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103 |
Issue |
2 |
Pages |
e03599 |
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Understanding the mechanisms that drive the change of biotic assemblages over space and time is the main quest of community ecology. Assessing the relative importance of dispersal and environmental species selection in a range of organismic sizes and motilities has been a fruitful strategy. A consensus for whether spatial and environmental distances operate similarly across spatial scales and taxa, however, has yet to emerge. We used censuses of four major groups of organisms (soil bacteria, fungi, ground insects, and trees) at two observation scales (1-m2 sampling point vs. 2,500-m2 plots) in a topographically standardized sampling design replicated in two tropical rainforests with contrasting relationships between spatial distance and nutrient availability. We modeled the decay of assemblage similarity for each taxon set and site to assess the relative contributions of spatial distance and nutrient availability distance. Then, we evaluated the potentially structuring effect of tree composition over all other taxa. The similarity of nutrient content in the litter and topsoil had a stronger and more consistent selective effect than did dispersal limitation, particularly for bacteria, fungi, and trees at the plot level. Ground insects, the only group assessed with the capacity of active dispersal, had the highest species turnover and the flattest nonsignificant distance−decay relationship, suggesting that neither dispersal limitation nor nutrient availability were fundamental drivers of their community assembly at this scale of analysis. Only the fungal communities at one of our study sites were clearly coordinated with tree composition. The spatial distance at the smallest scale was more important than nutrient selection for the bacteria, fungi, and insects. The lower initial similarity and the moderate variation in composition identified by these distance-decay models, however, suggested that the effects of stochastic sampling were important at this smaller spatial scale. Our results highlight the importance of nutrients as one of the main environmental drivers of rainforest communities irrespective of organismic or propagule size and how the overriding effect of the analytical scale influences the interpretation, leading to the perception of greater importance of dispersal limitation and ecological drift over selection associated with environmental niches at decreasing observation scales. |
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Ecological Society of America |
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no |
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EcoFoG @ webmaster @ |
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1022 |
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Duminil, J.; Caron, H.; Scotti, I.; Cazal, S.O.; Petit, R.J. |
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Blind population genetics survey of tropical rainforest trees |
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Journal Article |
| Year |
2006 |
Publication |
Molecular Ecology |
Abbreviated Journal |
Mol. Ecol. |
| Volume |
15 |
Issue |
12 |
Pages |
3505-3513 |
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Bayesian assignment tests; genetic diversity; geographical structure; South America; species delimitation |
| Abstract |
Rainforest tree species can be difficult to identify outside of their period of reproduction. Vascular tissues from Carapa spp. individuals were collected during a short field trip in French Guiana and analysed in the laboratory with nuclear and chloroplast markers. Using a Bayesian approach, > 90% of the samples could be assigned to one of two distinct clusters corresponding to previously described species, making it possible to estimate the genetic structure of each species and to identify cases of introgression. We argue that this blind procedure represents a first-choice rather than a fallback option whenever related taxa are investigated. |
| Address |
INRA, UMR Biodivers Genes & Ecosyst, F-33612 Cestas, France, Email: caron@pierroton.inra.fr |
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BLACKWELL PUBLISHING |
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0962-1083 |
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ISI:000241157400002 |
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no |
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EcoFoG @ eric.marcon @ |
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175 |
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Campillo, F.; Rakotozafy, R.; Rossi, V. |
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Parallel and interacting Markov chain Monte Carlo algorithm |
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Journal Article |
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2009 |
Publication |
Mathematics and Computers in Simulation |
Abbreviated Journal |
Math. Comput. Simul. |
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79 |
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12 |
Pages |
3424-3433 |
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Markov chain Monte Carlo method; Interacting chains; Hidden Markov model |
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In many situations it is important to be able to propose N independent realizations of a given distribution law. We propose a strategy for making N parallel Monte Carlo Markov chains (MCMC) interact in order to get an approximation of an independent N-sample of a given target law. In this method each individual chain proposes candidates for all other chains. We prove that the set of interacting chains is itself a MCMC method for the product of N target measures. Compared to independent parallel chains this method is more time consuming. but we show through examples that it possesses many advantages. This approach is applied to a biomass evolution model. (C) 2009 IMACS. Published by Elsevier B.V. All rights reserved. |
| Address |
[Rossi, Vivien] CIRAD, Res Unit, Montpellier, France, Email: Fabien.Campillo@inria.fr |
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ELSEVIER SCIENCE BV |
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0378-4754 |
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ISI:000269289100006 |
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no |
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EcoFoG @ eric.marcon @ |
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197 |
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Stahl, C.; Fontaine, S.; Klumpp, K.; Picon-Cochard, C.; Grise, M.M.; Dezecache, C.; Ponchant, L.; Freycon, V.; Blanc, L.; Bonal, D.; Burban, B.; Soussana, J.-F.; Blanfort, V. |
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Continuous soil carbon storage of old permanent pastures in Amazonia |
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Journal Article |
| Year |
2017 |
Publication |
Global Change Biology |
Abbreviated Journal |
Glob Change Biol |
| Volume |
23 |
Issue |
8 |
Pages |
3382-3392 |
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carbon storage; CN coupling; deep soil; mixed-grass pasture; native forest |
| Abstract |
Amazonian forests continuously accumulate carbon (C) in biomass and in soil, representing a carbon sink of 0.42–0.65 GtC yr−1. In recent decades, more than 15% of Amazonian forests have been converted into pastures, resulting in net C emissions (~200 tC ha−1) due to biomass burning and litter mineralization in the first years after deforestation. However, little is known about the capacity of tropical pastures to restore a C sink. Our study shows in French Amazonia that the C storage observed in native forest can be partly restored in old (≥24 year) tropical pastures managed with a low stocking rate (±1 LSU ha−1) and without the use of fire since their establishment. A unique combination of a large chronosequence study and eddy covariance measurements showed that pastures stored between −1.27 ± 0.37 and −5.31 ± 2.08 tC ha−1 yr−1 while the nearby native forest stored −3.31 ± 0.44 tC ha−1 yr−1. This carbon is mainly sequestered in the humus of deep soil layers (20–100 cm), whereas no C storage was observed in the 0- to 20-cm layer. C storage in C4 tropical pasture is associated with the installation and development of C3 species, which increase either the input of N to the ecosystem or the C:N ratio of soil organic matter. Efforts to curb deforestation remain an obvious priority to preserve forest C stocks and biodiversity. However, our results show that if sustainable management is applied in tropical pastures coming from deforestation (avoiding fires and overgrazing, using a grazing rotation plan and a mixture of C3 and C4 species), they can ensure a continuous C storage, thereby adding to the current C sink of Amazonian forests. |
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1365-2486 |
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no |
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EcoFoG @ webmaster @ |
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783 |
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Lebrini, M.; Robert, F.; Vezin, H.; Roos, C. |
| Title |
Electrochemical and quantum chemical studies of some indole derivatives as corrosion inhibitors for C38 steel in molar hydrochloric acid |
Type |
Journal Article |
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2010 |
Publication |
Corrosion Science |
Abbreviated Journal |
Corrosion Sci. |
| Volume |
52 |
Issue |
10 |
Pages |
3367-3376 |
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Steel; EIS; Raman spectroscopy; Polarization; Acid inhibition |
| Abstract |
A comparative study of 9H-pyrido[3,4-b]indole (norharmane) and 1-methyl-9H-pyrido[3,4-b]indole (harmane) as inhibitors for C38 steel corrosion in 1 M HCl solution at 25 degrees C was carried out. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques were applied to study the metal corrosion behavior in the absence and presence of different concentrations of these inhibitors. The OCP as a function of time were also established. Cathodic and anodic polarization curves show that norharmane and harmane are a mixed-type inhibitors. Adsorption of indole derivatives on the C38 steel surface, in 1 M HCl solution, follows the Langmuir adsorption isotherm model. The Delta G degrees(ads) values were calculated and discussed. The potential of zero charge (PZC) of the C38 steel in inhibited solution was studied by the EIS method, and a mechanism for the adsorption process was proposed. Raman spectroscopy confirmed that indole molecules strongly adsorbed onto the steel surface. The electronic properties of indole derivates, obtained using the AM1 semi-empirical quantum chemical approach, were correlated with their experimental efficiencies using the linear resistance model (LR). (C) 2010 Elsevier Ltd. All rights reserved. |
| Address |
[Robert, F.; Roos, C.] UAG UMR ECOFOG, Lab Mat & Mol Milieu Amazonien, Cayenne 97337, French Guiana, Email: christophe.roos@guyane.univ-ag.fr |
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PERGAMON-ELSEVIER SCIENCE LTD |
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0010-938X |
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ISI:000281315500026 |
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no |
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EcoFoG @ eric.marcon @ |
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44 |
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Harper, Anna B. ; Williams, Karina E. ; McGuire, Patrick ; Duran Rojas, Maria Carolina ; Hemming, Debbie ; Verhoef, Anne ; Huntingford, Chris ; Rowland, Lucy ; Marthews, Toby ; Breder Eller, Cleiton ; Mathison, Camilla ; Nobrega, Rodolfo L.B. ; Gedney, Nicola ; Vidale, Pier Luigi ; Otu-Larbi, Fred ; Pandey, Divya |
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Improvement of modeling plant responses to low soil moisture in JULESvn4.9 and evaluation against flux tower measurements |
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Journal Article |
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2021 |
Publication |
Geoscientific Model Development |
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14 |
Issue |
6 |
Pages |
3269-3294 |
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Drought is predicted to increase in the future due to climate change, bringing with it myriad impacts on ecosystems. Plants respond to drier soils by reducing stomatal conductance in order to conserve water and avoid hydraulic damage. Despite the importance of plant drought responses for the global carbon cycle and local and regional climate feedbacks, land surface models are unable to capture observed plant responses to soil moisture stress. We assessed the impact of soil moisture stress on simulated gross primary productivity (GPP) and latent energy flux (LE) in the Joint UK Land Environment Simulator (JULES) vn4.9 on seasonal and annual timescales and evaluated 10 different representations of soil moisture stress in the model. For the default configuration, GPP was more realistic in temperate biome sites than in the tropics or high-latitude (cold-region) sites, while LE was best simulated in temperate and high-latitude (cold) sites. Errors that were not due to soil moisture stress, possibly linked to phenology, contributed to model biases for GPP in tropical savanna and deciduous forest sites. We found that three alternative approaches to calculating soil moisture stress produced more realistic results than the default parameterization for most biomes and climates. All of these involved increasing the number of soil layers from 4 to 14 and the soil depth from 3.0 to 10.8 m. In addition, we found improvements when soil matric potential replaced volumetric water content in the stress equation (the “soil14psi” experiments), when the critical threshold value for inducing soil moisture stress was reduced (“soil14p0”), and when plants were able to access soil moisture in deeper soil layers (“soil14_dr*2”). For LE, the biases were highest in the default configuration in temperate mixed forests, with overestimation occurring during most of the year. At these sites, reducing soil moisture stress (with the new parameterizations mentioned above) increased LE and increased model biases but improved the simulated seasonal cycle and brought the monthly variance closer to the measured variance of LE. Further evaluation of the reason for the high bias in LE at many of the sites would enable improvements in both carbon and energy fluxes with new parameterizations for soil moisture stress. Increasing the soil depth and plant access to deep soil moisture improved many aspects of the simulations, and we recommend these settings in future work using JULES or as a general way to improve land surface carbon and water fluxes in other models. In addition, using soil matric potential presents the opportunity to include plant functional type-specific parameters to further improve modeled fluxes. |
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European Geosciences Union |
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EcoFoG @ webmaster @ |
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1057 |
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