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Author Dejean, Alain ; Petitclerc, Frédéric ; Azémar, Frédéric ; Rossi, Vivien
Title Nutrient provisioning of its host myrmecophytic tree by a temporary social parasite of a plant-ant Type Journal Article
Year 2021 Publication Biological Journal of the Linnean Society Abbreviated Journal
Volume 133 Issue 3 Pages 744-750
Keywords
Abstract (up) One of the most advanced ant–plant mutualisms is represented by myrmecophytes sheltering colonies of some plant-ant species in hollow structures called domatia. In turn, the myrmecophytes benefit from biotic protection and sometimes nutrient provisioning (myrmecotrophy). Furthermore, over the course of evolution, some ant species have become social parasites of others. In this general context, we studied the relationship between its host trees and Azteca andreae (Dolichoderinae), a temporary social parasite of the plant-ant Azteca ovaticeps, and, as such, obligatorily associated with myrmecophytic Cecropia obtusa trees (Urticaceae). A first experiment showed that the δ15N values of the young leaves of Cecropia sheltering a mature A. andreae colony were very similar to those for trees sheltering Azteca alfari or A. ovaticeps, two typical Cecropia mutualists for which myrmecotrophy is known. In a second experiment, by injecting a 15N-labelled glycine solution into locusts given as prey to A. andreae colonies, we triggered an increase in δ15N in the young leaves of their host Cecropia. Thus, 15N passed from the prey to the host trees, explaining the outcomes of the first experiment. We discuss these results in light of the notion of ‘by-product benefits’.
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Corporate Author Thesis
Publisher Oxford Academy Place of Publication Editor
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Call Number EcoFoG @ webmaster @ Serial 1009
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Author Piponiot, C.; Derroire, G.; Descroix, L.; Mazzei, L.; Rutishauser, E.; Sist, P.; Hérault, B.
Title Assessing timber volume recovery after disturbance in tropical forests – A new modelling framework Type Journal Article
Year 2018 Publication Ecological Modelling Abbreviated Journal
Volume 384 Issue Pages 353-369
Keywords Disturbance; Ecosystem modelling; Recovery; Sustainability; Tropical forest management
Abstract (up) One third of contemporary tropical forests is designated by national forest services for timber production. Tropical forests are also increasingly affected by anthropogenic disturbances. However, there is still much uncertainty around the capacity of tropical forests to recover their timber volume after logging as well as other disturbances such as fires, large blow-downs and extreme droughts, and thus on the long-term sustainability of logging. We developed an original Bayesian hierarchical model of Volume Dynamics with Differential Equations (VDDE) to infer the dynamic of timber volumes as the result of two ecosystem processes: volume gains from tree growth and volume losses from tree mortality. Both processes are expressed as explicit functions of the forest maturity, i.e. the overall successional stage of the forest that primarily depends on the frequency and severity of the disturbances that the forest has undergone. As a case study, the VDDE model was calibrated with data from Paracou, a long-term disturbance experiment in a neotropical forest where over 56 ha of permanent forest plots were logged with different intensities and censused for 31 years. With this model, we could predict timber recovery at Paracou at the end of a cutting cycle depending on the logging intensity, the rotation cycle length, and the proportion of commercial volume. The VDDE modelling framework developed presents three main advantages: (i) it can be calibrated with large tree inventories which are widely available from national forest inventories or logging concession management plans and are easy to measure, both on the field and with remote sensing; (ii) it depends on only a few input parameters, which can be an advantage in tropical regions where data availability is scarce; (iii) the modelling framework is flexible enough to explicitly include the effect of other types of disturbances (both natural and anthropogenic: e.g. blow-downs, fires and climate change) on the forest maturity, and thus to predict future timber provision in the tropics in a context of global changes. © 2018 Elsevier B.V.
Address INPHB (Institut National Polytechnique Félix Houphouet Boigny), Yamoussoukro, Cote d'Ivoire
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Notes Export Date: 1 September 2018 Approved no
Call Number EcoFoG @ webmaster @ Serial 813
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Author Wagner, F.H.; Herault, B.; Rossi, V.; Hilker, T.; Maeda, E.E.; Sanchez, A.; Lyapustin, A.I.; Galvão, L.S.; Wang, Y.; Aragão, L.E.O.C.
Title Climate drivers of the Amazon forest greening Type Journal Article
Year 2017 Publication PLoS ONE Abbreviated Journal
Volume 12 Issue 7 Pages e0180932
Keywords
Abstract (up) Our limited understanding of the climate controls on tropical forest seasonality is one of the biggest sources of uncertainty in modeling climate change impacts on terrestrial ecosystems. Combining leaf production, litterfall and climate observations from satellite and ground data in the Amazon forest, we show that seasonal variation in leaf production is largely triggered by climate signals, specifically, insolation increase (70.4% of the total area) and precipitation increase (29.6%). Increase of insolation drives leaf growth in the absence of water limitation. For these non-water-limited forests, the simultaneous leaf flush occurs in a sufficient proportion of the trees to be observed from space. While tropical cycles are generally defined in terms of dry or wet season, we show that for a large part of Amazonia the increase in insolation triggers the visible progress of leaf growth, just like during spring in temperate forests. The dependence of leaf growth initiation on climate seasonality may result in a higher sensitivity of these ecosystems to changes in climate than previously thought.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Address College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
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Notes Export Date: 3 August 2017 Approved no
Call Number EcoFoG @ webmaster @ Serial 760
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Author Latouche-Halle, C.; Ramboer, A.; Bandou, E.; Caron, H.; Kremer, A.
Title Long-distance pollen flow and tolerance to selfing in a neotropical tree species Type Journal Article
Year 2004 Publication Molecular Ecology Abbreviated Journal Mol. Ecol.
Volume 13 Issue 5 Pages 1055-1064
Keywords Dicorynia guianensis; microsatellites; outcrossing rate; pollen flow; reproductive success; tropical tree
Abstract (up) Outcrossing rates, pollen dispersal and male mating success were assessed in Dicorynia guianensis Amshoff, a neotropical tree endemic to the Guiana shield. All adult trees within a continuous area of 40 ha (n = 157) were mapped, and were genotyped with six microsatellite loci. In addition, progenies were genotyped from 22 mature trees. At the population level, the species was mostly outcrossing (t(m) = 0.89) but there was marked variation among individuals. One tree exhibited mixed mating, confirming earlier results obtained with isozymes that D. guianensis can tolerate selfing. A Bayesian extension of the fractional paternity method was used for paternity analysis, and was compared with the neighbourhood method used widely for forest trees. Both methods indicated that pollen dispersal was only weakly related to distance between trees within the study area, and that the majority (62%) of pollen came from outside the study stand. Using maximum likelihood, male potential population size was estimated to be 1119, corresponding to a neighbourhood size of 560 hectares. Male mating success was, however, related to the diameter of the stem and to flowering intensity assessed visually. The mating behaviour of D. guianensis is a combination of long-distance pollen flow and occasional selfing. The species can still reproduce when it is extremely rare, either by selfing or by dispersing pollen at long distances. These results, together with the observation that male mating success was correlated with the size of the trees, could be implemented in management procedures aiming at regenerating the species.
Address INRA, UMR Ecol Forets Guyane, F-97387 Kourou, France, Email: caron@pierroton.mra.fr
Corporate Author Thesis
Publisher BLACKWELL PUBLISHING LTD 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:000221016300007 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 237
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Author Marcon, E.; Puech, F.
Title A typology of distance-based measures of spatial concentration Type Journal Article
Year 2017 Publication Regional Science and Urban Economics Abbreviated Journal Regional Science and Urban Economics
Volume 62 Issue Pages 56-67
Keywords Agglomeration; Aggregation; Economic geography; Point patterns; Spatial concentration
Abstract (up) Over the last decade, distance-based methods have been introduced and then improved in the field of spatial economics to gauge the geographic concentration of activities. There is a growing literature on this theme including new tools, discussions on their specific properties and various applications. However, there is currently no typology of distance-based methods. This paper fills that gap. The proposed classification helps understand all the properties of distance-based methods and proves that they are variations on the same framework. © 2016 Elsevier B.V.
Address RITM, Univ. Paris-Sud, CREST, Université Paris-Saclay, Sceaux, France
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Notes Export Date: 17 January 2017 Approved no
Call Number EcoFoG @ webmaster @ Serial 704
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Author Guevara, J.E.; Damasco, G.; Baraloto, C.; Fine, P.V.A.; Peñuela, M.C.; Castilho, C.; Vincentini, A.; Cárdenas, D.; Wittmann, F.; Targhetta, N.; Phillips, O.; Stropp, J.; Amaral, I.; Maas, P.; Monteagudo, A.; Jimenez, E.M.; Thomas, R.; Brienen, R.; Duque, A.; Magnusson, W.; Ferreira, C.; Honorio, E.; de Almeida Matos, F.; Arevalo, F.R.; Engel, J.; Petronelli, P.; Vasquez, R.; ter Steege, H.
Title Low Phylogenetic Beta Diversity and Geographic Neo-endemism in Amazonian White-sand Forests Type Journal Article
Year 2016 Publication Biotropica Abbreviated Journal Biotropica
Volume 48 Issue 1 Pages 34-46
Keywords Amazon; Neo-endemism; Phylogenetic beta diversity; Recent diversification; White sands
Abstract (up) Over the past three decades, many small-scale floristic studies of white-sand forests across the Amazon basin have been published. Nonetheless, a basin-wide description of both taxonomic and phylogenetic alpha and beta diversity at regional scales has never been achieved. We present a complete floristic analysis of white-sand forests across the Amazon basin including both taxonomic and phylogenetic diversity. We found strong regional differences in the signal of phylogenetic community structure with both overall and regional Net Relatedness Index and Nearest Taxon Index values found to be significantly positive leading to a pattern of phylogenetic clustering. Additionally, we found high taxonomic dissimilarity but low phylogenetic dissimilarity in pairwise community comparisons. These results suggest that recent diversification has played an important role in the assembly of white-sand forests causing geographic neo-endemism patterns at the regional scale. © 2016 The Association for Tropical Biology and Conservation.
Address Ecology and Biodiversity Group, Utrecht University, Utrecht, Netherlands
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Notes Cited By :3; Export Date: 12 February 2016 Approved no
Call Number EcoFoG @ webmaster @ Serial 660
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Author Degen, B.; Blanc, L.; Caron, H.; Maggia, L.; Kremer, A.; Gourlet-Fleury, S.
Title Impact of selective logging on genetic composition and demographic structure of four tropical tree species Type Journal Article
Year 2006 Publication Biological Conservation Abbreviated Journal Biol. Conserv.
Volume 131 Issue 3 Pages 386-401
Keywords demography; genetic diversity; logging; phenology; pollen and seed dispersal; simulation; trees; tropics
Abstract (up) Over-exploitation and fragmentation are serious problems for tropical forests. Most sustainable forest management practices avoid clear-cuts and apply selective logging systems focused on a few commercial species. We applied a simulation model to estimate the impact of such selective logging scenarios on the genetic diversity and demography of four tropical tree species from French Guiana. The simulations used data on genetic and demographic composition, growth, phenology and pollen and seed dispersal obtained for Dicorynia guianensis, Sextonia rubra, Symphonia globulifera and Vouacapoua americana at the experimental site in Paracou. Whereas Symphonia globulifera serves as a model for a species with low logging pressure, the other three species represent the most exploited tree species in French Guiana. In simulations with moderate logging, typical for French Guiana, with large cutting diameter (> 60 cm diameter) and long cutting cycles (65 years), the two species V. americana and Sextonia rubra were not able to recover their initial stock at the end of the rotation period, with a large decrease in the number of individuals and in basal area. Under a more intensive logging system (cutting diameter > 45 cm diameter, cutting cycles of 30 years) that is common practice in the Brazilian Amazon, only Symphonia globulifera showed no negative impact. Generally, the differences between the genetic parameters in the control scenarios without logging and the logging scenarios were surprisingly small. The main reasons for this were the overlapping of generations and the effective dispersal ability of gene vectors in all species, which guarantee relative homogeneity of the genetic structure in different age classes. Nevertheless, decreasing the population size by logging reduced the number of genotypes and caused higher genetic distances between the original population and the population at the end of the logging cycles. Sensitivity analysis showed that genetic changes in the logging scenarios were principally determined by the growth, densities and cutting diameter of each species, and only to a very small extent by the reproductive system including factors such as pollen and seed dispersal and flowering phenology. (c) 2006 Elsevier Ltd. All rights reserved.
Address BFH, Inst Forstgenet & Forstpflanzenzuchtung, D-22927 Grosshansdorf, Germany, Email: b.degen@holz.uni-hamburg.de
Corporate Author Thesis
Publisher ELSEVIER SCI LTD Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0006-3207 ISBN Medium
Area Expedition Conference
Notes ISI:000239139400004 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 180
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Author Baraloto, C.; Paine, C.E.T.; Patino, S.; Bonal, D.; Herault, B.; Chave, J.
Title Functional trait variation and sampling strategies in species-rich plant communities Type Journal Article
Year 2010 Publication Functional Ecology Abbreviated Journal Funct. Ecol.
Volume 24 Issue 1 Pages 208-216
Keywords French Guiana; functional diversity; plant traits; specific leaf area; wood density; sampling design; tropical forest
Abstract (up) P> Despite considerable interest in the application of plant functional traits to questions of community assembly and ecosystem structure and function, there is no consensus on the appropriateness of sampling designs to obtain plot-level estimates in diverse plant communities. We measured 10 plant functional traits describing leaf and stem morphology and ecophysiology for all trees in nine 1-ha plots in terra firme lowland tropical rain forests of French Guiana (N = 4709). We calculated, by simulation, the mean and variance in trait values for each plot and each trait expected under seven sampling methods and a range of sampling intensities. Simulated sampling methods included a variety of spatial designs, as well as the application of existing data base values to all individuals of a given species. For each trait in each plot, we defined a performance index for each sampling design as the proportion of resampling events that resulted in observed means within 5% of the true plot mean, and observed variance within 20% of the true plot variance. The relative performance of sampling designs was consistent for estimations of means and variances. Data base use had consistently poor performance for most traits across all plots, whereas sampling one individual per species per plot resulted in relatively high performance. We found few differences among different spatial sampling strategies; however, for a given strategy, increased intensity of sampling resulted in markedly improved accuracy in estimates of trait mean and variance. We also calculated the financial cost of each sampling design based on data from our 'every individual per plot' strategy and estimated the sampling and botanical effort required. The relative performance of designs was strongly positively correlated with relative financial cost, suggesting that sampling investment returns are relatively constant. Our results suggest that trait sampling for many objectives in species-rich plant communities may require the considerable effort of sampling at least one individual of each species in each plot, and that investment in complete sampling, though great, may be worthwhile for at least some traits.
Address [Baraloto, Christopher; Patino, Sandra; Bonal, Damien] INRA, UMR Ecol Forets Guyane, F-97387 Kourou, French Guiana, Email: chris.baraloto@ecofog.gf
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 0269-8463 ISBN Medium
Area Expedition Conference
Notes ISI:000273455500024 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 72
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Author Gonzalez, M.A.; Roger, A.; Courtois, E.A.; Jabot, F.; Norden, N.; Paine, C.E.T.; Baraloto, C.; Thebaud, C.; Chave, J.
Title Shifts in species and phylogenetic diversity between sapling and tree communities indicate negative density dependence in a lowland rain forest Type Journal Article
Year 2010 Publication Journal of Ecology Abbreviated Journal J. Ecol.
Volume 98 Issue 1 Pages 137-146
Keywords APG II plus rbcL megatree; density dependence; DNA barcoding; French Guiana; phylogenetic diversity; species diversity; tropical plant communities
Abstract (up) P>1. As trees in a given cohort progress through ontogeny, many individuals die. This risk of mortality is unevenly distributed across species because of many processes such as habitat filtering, interspecific competition and negative density dependence. Here, we predict and test the patterns that such ecological processes should inscribe on both species and phylogenetic diversity as plants recruit from saplings to the canopy. 2. We compared species and phylogenetic diversity of sapling and tree communities at two sites in French Guiana. We surveyed 2084 adult trees in four 1-ha tree plots and 943 saplings in sixteen 16-m2 subplots nested within the tree plots. Species diversity was measured using Fisher's alpha (species richness) and Simpson's index (species evenness). Phylogenetic diversity was measured using Faith's phylogenetic diversity (phylogenetic richness) and Rao's quadratic entropy index (phylogenetic evenness). The phylogenetic diversity indices were inferred using four phylogenetic hypotheses: two based on rbcLa plastid DNA sequences obtained from the inventoried individuals with different branch lengths, a global phylogeny available from the Angiosperm Phylogeny Group, and a combination of both. 3. Taxonomic identification of the saplings was performed by combining morphological and DNA barcoding techniques using three plant DNA barcodes (psbA-trnH, rpoC1 and rbcLa). DNA barcoding enabled us to increase species assignment and to assign unidentified saplings to molecular operational taxonomic units. 4. Species richness was similar between saplings and trees, but in about half of our comparisons, species evenness was higher in trees than in saplings. This suggests that negative density dependence plays an important role during the sapling-to-tree transition. 5. Phylogenetic richness increased between saplings and trees in about half of the comparisons. Phylogenetic evenness increased significantly between saplings and trees in a few cases (4 out of 16) and only with the most resolved phylogeny. These results suggest that negative density dependence operates largely independently of the phylogenetic structure of communities. 6. Synthesis. By contrasting species richness and evenness across size classes, we suggest that negative density dependence drives shifts in composition during the sapling-to-tree transition. In addition, we found little evidence for a change in phylogenetic diversity across age classes, suggesting that the observed patterns are not phylogenetically constrained.
Address [Gonzalez, Mailyn A.; Roger, Aurelien; Courtois, Elodie A.; Jabot, Franck; Norden, Natalia; Thebaud, Christophe; Chave, Jerome] Univ Toulouse 3, Lab Evolut & Diversite Biol, UMR 5174, CNRS, F-31062 Toulouse, France, Email: gonzalez.mailyn@gmail.com
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 0022-0477 ISBN Medium
Area Expedition Conference
Notes ISI:000272657400015 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 88
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Author Herault, B.; Ouallet, J.; Blanc, L.; Wagner, F.; Baraloto, C.
Title Growth responses of neotropical trees to logging gaps Type Journal Article
Year 2010 Publication Journal of Applied Ecology Abbreviated Journal J. Appl. Ecol.
Volume 47 Issue 4 Pages 821-831
Keywords canopy openings; functional traits; incidence function model; light partitioning; selective logging; tree growth rates; tropical rain forest
Abstract (up) P>1. Modelling growth strategies among tropical trees is an important objective in predicting the response of tree dynamics to selective logging and in gaining insights into the ecological processes that structure tree communities in managed tropical forests. 2. We developed a disturbance index to model the effects of distance to and area of logging gaps on stem radial growth rates. This index was tested using census data of 43 neotropical tree species, representing a variety of life-history strategies and developmental stages, from a selectively logged forest at Paracou, French Guiana. Growth strategies were analyzed in light of two indicators: the inherent species growth rate (when disturbance index is null) and the species reaction (change in growth rate) to logging gaps. 3. Across species, the predicted inherent growth rates in unlogged forest ranged from 0 center dot 25 to 6 center dot 47 mm year-1, with an average growth of 2 center dot 29 mm year-1. Ontogenetic shifts in inherent growth rate were found in 26 of the 43 species. 4. Species growth response to logging gaps varied widely among species but was significantly positive for 27 species. The effect of ontogeny on growth response to logging was retained for 14 species, and species with inherent fast growth rate (5 mm year-1) responded less to logging gap disturbances than did species with slow inherent growth (1 mm year-1). 5. Functional traits explained 19-42% of the variation in the inherent growth rate and in species' response across all developmental stages. Whereas maximum diameters and seed mass were strong predictors of inherent growth rate, maximum height, wood density, mode of germination and stem architecture were additionally involved in tree growth response. 6. Synthesis and applications: This study provides a necessary framework for developing predictive post-logging growth models for the thousands of species comprising tropical forests and is sufficiently general to apply to a broad range of managed tropical forests.
Address [Herault, Bruno] Univ Antilles Guyane, UMR Ecol Forets Guyane, F-97387 Kourou, France, Email: bruno.herault@ecofog.gf
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 0021-8901 ISBN Medium
Area Expedition Conference
Notes ISI:000279405100012 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 53
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