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Author (up) González, A.L.; Céréghino, R.; Dézerald, O.; Farjalla, V.F.; Leroy, C.; Richardson, B.A.; Richardson, M.J.; Romero, G.Q.; Srivastava, D.S. url  doi
openurl 
  Title Ecological mechanisms and phylogeny shape invertebrate stoichiometry: A test using detritus-based communities across Central and South America Type Journal Article
  Year 2018 Publication Functional Ecology Abbreviated Journal Funct Ecol  
  Volume 32 Issue 10 Pages 2448-2463  
  Keywords body size scaling; carnivores; detritivores; ecological stoichiometry; macroinvertebrates; nitrogen; phosphorous; phylogenetic signal  
  Abstract Stoichiometric differences among organisms can affect trophic interactions and rates of nutrient cycling within ecosystems. However, we still know little about either the underlying causes of these stoichiometric differences or the consistency of these differences across large geographical extents. Here, we analyse elemental (carbon, nitrogen, phosphorus) composition of 872 aquatic macroinvertebrates (71 species) inhabiting tank bromeliads (n = 140) from five distantly located sites across Central and South America to (i) test phylogenetic, trophic and body size scaling explanations for why organisms differ in elemental composition and (ii) determine whether patterns in elemental composition are universal or context dependent. Taxonomy explained most variance in elemental composition, even though phylogenetic signals were weak and limited to regional spatial extents and to the family level. The highest elemental contents and lowest carbon:nutrient ratios were found in organisms at high trophic levels and with smaller body size, regardless of geographical location. Carnivores may have higher nutrient content and lower carbon:nutrient ratios than their prey, as organisms optimize growth by choosing the most nutrient-rich resources to consume and then preferentially retain nutrients over carbon in their bodies. Smaller organisms grow proportionally faster than large organisms and so are predicted to have higher nutrient requirements to fuel RNA and protein synthesis. Geography influenced the magnitude, more than the direction, of the ecological and/or phylogenetic effects on elemental composition. Overall, our results show that both ecological (i.e. trophic group) and evolutionary drivers explain among-taxa variation in the elemental content of invertebrates, whereas intraspecific variation is mainly a function of body size. Our findings also demonstrate that restricting analyses of macroinvertebrate stoichiometry solely to either the local scale or species level affects inferences of the patterns in invertebrate elemental content and their underlying mechanisms.  
  Address  
  Corporate Author Thesis  
  Publisher John Wiley & Sons, Ltd (10.1111) Place of Publication Editor  
  Language Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 0269-8463 ISBN Medium  
  Area Expedition Conference  
  Notes doi: 10.1111/1365-2435.13197 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 849  
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Author (up) Goulamoussene, Y.; Bedeau, C.; Descroix, L.; Linguet, L.; Herault, B. pdf  url
doi  openurl
  Title Environmental control of natural gap size distribution in tropical forests Type Journal Article
  Year 2017 Publication Biogeosciences Abbreviated Journal Biogeosciences  
  Volume 14 Issue 2 Pages 353-364  
  Keywords  
  Abstract Natural disturbances are the dominant form of forest regeneration and dynamics in unmanaged tropical forests. Monitoring the size distribution of treefall gaps is important to better understand and predict the carbon budget in response to land use and other global changes. In this study, we model the size frequency distribution of natural canopy gaps with a discrete power law distribution. We use a Bayesian framework to introduce and test, using Monte Carlo Markov chain and Kuo-Mallick algorithms, the effect of local physical environment on gap size distribution. We apply our methodological framework to an original light detecting and ranging dataset in which natural forest gaps were delineated over 30 000 ha of unmanaged forest. We highlight strong links between gap size distribution and environment, primarily hydrological conditions and topography, with large gaps being more frequent on floodplains and in wind-exposed areas. In the future, we plan to apply our methodological framework on a larger scale using satellite data. Additionally, although gap size distribution variation is clearly under environmental control, variation in gap size distribution in time should be tested against climate variability. © Author(s) 2017.  
  Address Cirad, UMR EcoFoG, AgroParisTech, CNRS, Inra, Univ Antilles, Univ Guyane, Kourou, French Guiana  
  Corporate Author Thesis  
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  Notes Export Date: 7 February 2017 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 729  
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Author (up) Goulamoussene, Youven; Bedeau, Caroline; Descroix, Laurent; Deblauwe, Vincent; Linguet, Laurent; Herault, Bruno pdf  doi
openurl 
  Title Weak Environmental Controls of Tropical Forest Canopy Height in the Guiana Shield Remote Sensing Type Journal Article
  Year 2016 Publication Remote Sensing Abbreviated Journal Remote Sens  
  Volume 8 Issue 9 Pages 747  
  Keywords  
  Abstract Canopy height is a key variable in tropical forest functioning and for regional carbon inventories. We investigate the spatial structure of the canopy height of a tropical forest, its relationship with environmental physical covariates, and the implication for tropical forest height variation mapping. Making use of high-resolution maps of LiDAR-derived Digital Canopy Model (DCM) and environmental covariates from a Digital Elevation Model (DEM) acquired over 30,000 ha of tropical forest in French Guiana, we first show that forest canopy height is spatially correlated up to 2500 m. Forest canopy height is significantly associated with environmental variables, but the degree of correlation varies strongly with pixel resolution. On the whole, bottomland forests generally have lower canopy heights than hillslope or hilltop forests. However, this global picture is very noisy at local scale likely because of the endogenous gap-phase forest dynamic processes. Forest canopy height has been predictively mapped across a pixel resolution going from 6 m to 384 m mimicking a low resolution case of 3 points·km − 2 . Results of canopy height mapping indicated that the error for spatial model with environment effects decrease from 8.7 m to 0.91 m, depending of the pixel resolution. Results suggest that, outside the calibration plots, the contribution of environment in shaping the global canopy height distribution is quite limited. This prevents accurate canopy height mapping based only on environmental information, and suggests that precise canopy height maps, for local management purposes, can only be obtained with direct LiDAR monitoring.  
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  Call Number EcoFoG @ webmaster @ Serial 724  
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Author (up) Gourlet-Fleury, S.; Blanc, L.; Picard, N.; Sist, P.; Dick, J.; Nasi, R.; Swaine, M.D.; Forni, E. openurl 
  Title Grouping species for predicting mixed tropical forest dynamics: looking for a strategy Type Journal Article
  Year 2005 Publication Annals of Forest Science Abbreviated Journal Ann. For. Sci.  
  Volume 62 Issue 8 Pages 785-796  
  Keywords cross-comparisons; functional groups; modelling strategy; species classifications  
  Abstract The high species diversity of mixed tropical forests hinders the development of forest dynamic models. A solution commonly adopted is to cluster species in groups. There are various methods for grouping species that can be linked to three strategies (i) the ecological subjective strategy, (ii) the ecological data-driven strategy, and (iii) the dynamic process strategy. In the first two strategies a species will be assigned to a single group while in the latter strategy, a specific grouping is defined for each process of population dynamics ( typically based on recruitment, growth, mortality). Little congruency or convergence is observed in the literature between any two classifications of species. This may be explained by the independence between the sets of tree characters used to build species groups, or by the intra-specific variability of these characters. We therefore recommend the dynamic process strategy as the most convenient strategy for building groups of species.  
  Address Cirad Foret, F-34398 Montpellier, France, Email: sylvie.gourlet-fleury@cirad.fr  
  Corporate Author Thesis  
  Publisher EDP SCIENCES S A Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1286-4560 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000233972500001 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 228  
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Author (up) Gourlet-Fleury, S.; Comu, G.; Jesel, S.; Dessard, H.; Jourget, J.G.; Blanc, L.; Picard, N. openurl 
  Title Using models to predict recovery and assess tree species vulnerability in logged tropical forests: A case study from French Guiana Type Journal Article
  Year 2005 Publication Forest Ecology and Management Abbreviated Journal For. Ecol. Manage.  
  Volume 209 Issue 1-2 Pages 69-86  
  Keywords matrix model; individual-based spatially explicit model; regeneration; recruitment; long-term population dynamics  
  Abstract A major challenge for forest managers is to define the optimal cutting cycle to ensure that the resource is sustained in the long term. Matrix models of forest dynamics allow time-projection of diameter-class distributions and thus assessment of the time needed, after logging, to recover a given part of the exploitable stock. They are easy to build and they only require, as input variables, the diameter structure of the population(s) under scope. However, such models are based on a coarse description of tree population dynamics and must be used with caution. In particular, as trees are only described from a diameter threshold (usually 10 cm dbh), recruitment of a new tree cannot be linked with the preceding generation since too much time elapsed between seed dispersal and the installation of a 10-cm recruit. This causes predictions of matrix models to be highly questionable in the long term when ingrowth to larger dbh classes greatly depends on the way recruitment has been modelled. We used a case study from French Guiana to test whether or not a simple matrix model is reliable enough to help forest managers choose between management alternatives. We focused on the major timber species Dicorynia guianensis Amshoff (Caesalpiniaceae) harvested under a selective cutting regime. We compared predictions of D. guianensis stock recovery in the short and long term provided by two models: StoMat, a non-regulated matrix model, and SELVA, a single-tree distance dependent model explicitly simulating the entire species life cycle. Both models were independently calibrated on data from Paracou permanent sample plots. We showed that: (i) the short-term recovery of the exploitable stock predicted by StoMat is reliable for a large range of disturbance conditions; (ii) recruitment implementation in StoMat does not influence projections until the third felling cycle; (iii) for shared initial stand conditions SELVA and StoMat give consistent mid- and long-term predictions: the simple recruitment model used into StoMat could efficiently summarise the regeneration processes of the species under low felling intensity. Our results indicate that the current felling regime used in French Guiana may not be sustainable on a long-term basis. In any case, no more than 60% of the initial stock would be recovered after logging. We conclude that simple models can provide as reliable predictions as more complicated ones. They may be sufficient to assess the recovery of a species' exploitable stock even in the long term, or at least assess the (un)sustainability of particular harvesting regimes. (c) 2005 Elsevier B.V. All rights reserved.  
  Address CIRAD, Dept Forets, F-34398 Montpellier 5, France, Email: sylvie.gourlet-fleury@cirad.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 0378-1127 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000228504600007 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 257  
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Author (up) Gourlet-Fleury, S.; Gazull, L.; Bigombe Logo, P.; Billand, A.; Bolaluembe, P.-C.; Boyemba, F.; Dessard, H.; Doucet, J.-L.; Doumenge, C.; Dubiez, E.; Durrieu De Madron, L.; Feintrenie, L.; Fomete, T.; Garcia, C.; Gillet, J.-F.; Herault, B.; Karsenty, A.; Menga, P.; Ngoya Kessy, A.M.; Pietsch, S.; Putz, J.; Rossi, V.; Sayer, J.; Sist, P.; Zongang Ngongang, A.A. pdf  url
openurl 
  Title Are logging concessions a threat to the peatlands in DRC? Type Journal Article
  Year 2017 Publication Bois et Forets des Tropiques Abbreviated Journal  
  Volume Issue 334 Pages 3-6  
  Keywords  
  Abstract  
  Address Université du Maine, France  
  Corporate Author Thesis  
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  Notes Export Date: 23 January 2018 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 788  
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Author (up) Gourlet-Fleury, S.; Rossi, V.; Rejou-Mechain, M.; Freycon, V.; Fayolle, A.; Saint-André, L.; Cornu, G.; Gérard, J.; Sarrailh, J.-M.; Flores, O.; Baya, F.; Billand, A.; Fauvet, N.; Gally, M.; Henry, M.; Hubert, D.; Pasquier, A.; Picard, N. url  openurl
  Title Environmental filtering of dense-wooded species controls above-ground biomass stored in African moist forests Type Journal Article
  Year 2011 Publication Journal of Ecology Abbreviated Journal J. Ecol.  
  Volume 99 Issue 4 Pages 981-990  
  Keywords Basal area; Central African Republic; Determinants of plant community diversity and structure; Life-history strategy; Soil fertility; Species sorting; Vital rates; Water reserve; Wood density; aboveground biomass; basal area; climate change; data set; database; diameter; forest ecosystem; forest inventory; life history trait; nutrient availability; physical property; plant community; resource availability; soil fertility; soil nutrient; soil texture; soil type; stem; tropical forest; wood; Central African Republic  
  Abstract 1.Regional above-ground biomass estimates for tropical moist forests remain highly inaccurate mostly because they are based on extrapolations from a few plots scattered across a limited range of soils and other environmental conditions. When such conditions impact biomass, the estimation is biased. The effect of soil types on biomass has especially yielded controversial results. 2.We investigated the relationship between above-ground biomass and soil type in undisturbed moist forests in the Central African Republic. We tested the effects of soil texture, as a surrogate for soil resources availability and physical constraints (soil depth and hydromorphy) on biomass. Forest inventory data were collected for trees ≥20cm stem diameter in 2754 0.5ha plots scattered over 4888km2. The plots contained 224 taxons, of which 209 were identified to species. Soil types were characterized from a 1:1000000 scale soil map. Species-specific values for wood density were extracted from the CIRAD's data base of wood technological properties. 3.We found that basal area and biomass differ in their responses to soil type, ranging from 17.8m2ha-1 (217.5tha-1) to 22.3m2ha-1 (273.3tha-1). While shallow and hydromorphic soils support forests with both low stem basal area and low biomass, forests on deep resource-poor soils are typically low in basal area but as high in biomass as forests on deep resource-rich soils. We demonstrated that the environmental filtering of slow growing dense-wooded species on resource-poor soils compensates for the low basal area, and we discuss whether this filtering effect is due to low fertility or to low water reserve. 4.Synthesis. We showed that soil physical conditions constrained the amount of biomass stored in tropical moist forests. Contrary to previous reports, our results suggest that biomass is similar on resource-poor and resource-rich soils. This finding highlights both the importance of taking into account soil characteristics and species wood density when trying to predict regional patterns of biomass. Our findings have implications for the evaluation of biomass stocks in tropical forests, in the context of the international negotiations on climate change. © 2011 The Authors. Journal of Ecology © 2011 British Ecological Society.  
  Address CIRAD, BP 4035, Libreville, Gabon  
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  ISSN 00220477 (Issn) ISBN Medium  
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  Notes Cited By (since 1996): 1; Export Date: 23 October 2011; Source: Scopus; Coden: Jecoa; doi: 10.1111/j.1365-2745.2011.01829.x; Language of Original Document: English; Correspondence Address: Gourlet-Fleury, S.; Cirad, UR BandSEF, Biens et Services des Ecosystèmes Forestiers tropicaux, Campus International de Baillarguet, TA C-105/D, F-34398, Montpellier, France; email: sylvie.gourlet-fleury@cirad.fr Approved no  
  Call Number EcoFoG @ webmaster @ Serial 361  
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Author (up) Grabchak, M.; Marcon, E.; Lang, G.; Zhang, Z. pdf  url
doi  openurl
  Title The generalized Simpson’s entropy is a measure of biodiversity Type Journal Article
  Year 2017 Publication Plos One Abbreviated Journal Plos One  
  Volume 12 Issue 3 Pages e0173305  
  Keywords  
  Abstract Modern measures of diversity satisfy reasonable axioms, are parameterized to produce diversity profiles, can be expressed as an effective number of species to simplify their interpretation, and come with estimators that allow one to apply them to real-world data. We introduce the generalized Simpson’s entropy as a measure of diversity and investigate its properties. We show that it has many useful features and can be used as a measure of biodiversity. Moreover, unlike most commonly used diversity indices, it has unbiased estimators, which allow for sound estimation of the diversity of poorly sampled, rich communities.  
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  Publisher Public Library of Science Place of Publication Editor  
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  Call Number EcoFoG @ webmaster @ Serial 742  
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Author (up) Grangier, J.; Dejean, A.; Male, P.J.G.; Orivel, J. openurl 
  Title Indirect defense in a highly specific ant-plant mutualism Type Journal Article
  Year 2008 Publication Naturwissenschaften Abbreviated Journal Naturwissenschaften  
  Volume 95 Issue 10 Pages 909-916  
  Keywords Allomerus decemarticulatus; Hirtella physophora; indirect defense; myrmecophytes; optimal defense theory  
  Abstract Although associations between myrmecophytes and their plant ants are recognized as a particularly effective form of protective mutualism, their functioning remains incompletely understood. This field study examined the ant-plant Hirtella physophora and its obligate ant associate Allomerus decemarticulatus. We formulated two hypotheses on the highly specific nature of this association: (1) Ant presence should be correlated with a marked reduction in the amount of herbivory on the plant foliage; (2) ant activity should be consistent with the “optimal defense” theory predicting that the most vulnerable and valuable parts of the plant are the best defended. We validated the first hypothesis by demonstrating that for ant-excluded plants, expanding leaves, but also newly matured ones in the long term, suffered significantly more herbivore damage than ant-inhabited plants. We showed that A. decemarticulatus workers represent both constitutive and inducible defenses for their host, by patrolling its foliage and rapidly recruiting nestmates to foliar wounds. On examining how these activities change according to the leaves' developmental stage, we found that the number of patrolling ants dramatically decreased as the leaves matured, while leaf wounds induced ant recruitment regardless of the leaf's age. The resulting level of these indirect defenses was roughly proportional to leaf vulnerability and value during its development, thus validating our second hypothesis predicting optimal protection. This led us to discuss the factors influencing ant activity on the plant's surface. Our study emphasizes the importance of studying both the constitutive and inducible components of indirect defense when evaluating its efficacy and optimality.  
  Address [Grangier, Julien; Dejean, Alain; Male, Pierre-Jean G.; Orivel, Jerome] Univ Toulouse 3, Lab Evolut & Diversite Biol, CNRS, UMR 5174, F-31062 Toulouse 9, France, Email: grangier@cict.fr  
  Corporate Author Thesis  
  Publisher SPRINGER Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0028-1042 ISBN Medium  
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  Notes ISI:000259737600002 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 207  
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Author (up) Grangier, J.; Dejean, A.; Male, P.J.G.; Solano, P.J.; Orivel, J. openurl 
  Title 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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