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Author Denis, T.; Richard-Hansen, C.; Brunaux, O.; Etienne, M.-P.; Guitet, S.; Herault, B. doi  openurl
  Title Biological traits, rather than environment, shape detection curves of large vertebrates in neotropical rainforests Type Journal Article
  Year 2017 Publication Ecological Applications Abbreviated Journal Ecol Appl  
  Volume 27 Issue 5 Pages 1564-1577  
  Keywords abundance; camouflage; distance sampling; encounter rate; French Guiana; hunting vulnerability; line transect; Neotropical terra firme rainforests; relative abundance  
  Abstract Line transect surveys are widely used in Neotropical rainforests to estimate the population abundance of medium- and large-sized vertebrates. The use of indices such as encounter rate has been criticized because the probability of animal detection may fluctuate due to the heterogeneity of environmental conditions among sites. In addition, the morphological and behavioral characteristics (biological traits) of species affect their detectability. In this study, we compared the extent to which environmental conditions and species’ biological traits bias abundance estimates in terra firme rainforests in French Guiana. The selected environmental conditions included both physical conditions and forest structure covariates, while the selected biological traits included the morphological and behavioral characteristics of species. We used the distance sampling method to model the detection probability as an explicit function of environmental conditions and biological traits and implemented a model selection process to determine the relative importance of each group of covariates. Biological traits contributed to the variability of animal detectability more than environmental conditions, which had only a marginal effect. Detectability was best for large animals with uniform or disruptive markings that live in groups in the canopy top. Detectability was worst for small, solitary, terrestrial animals with mottled markings. In the terra firme rainforests that represent ~80% of the Amazonia and Guianas regions, our findings support the use of relative indices such as the encounter rate to compare population abundance between sites in species-specific studies. Even though terra firme rainforests may appear similar between regions of Amazonia and the Guianas, comparability must be ensured, especially in forests disturbed by human activity. The detection probability can be used as an indicator of species’ vulnerability to hunting and, thus, to the risk of local extinction. Only a few biological trait covariates are required to correctly estimate the detectability of the majority of medium- and large-sized vertebrates. Thus, a biological trait model could be useful in predicting the detection probabilities of rare, uncommon, or localized species for which few data are available to fit the detection function.  
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  Call Number EcoFoG @ webmaster @ Serial (up) 764  
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Author Leba, L.-J.; Popovici, J.; Estevez, Y.; Pelleau, S.; Legrand, E.; Musset, L.; Duplais, C. pdf  url
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  Title Antiplasmodial activities of dyes against Plasmodium falciparum asexual and sexual stages: Contrasted uptakes of triarylmethanes Brilliant green, Green S (E142), and Patent Blue V (E131) by erythrocytes Type Journal Article
  Year 2017 Publication International Journal for Parasitology: Drugs and Drug Resistance Abbreviated Journal International Journal for Parasitology: Drugs and Drug Resistance  
  Volume 7 Issue 3 Pages 314-320  
  Keywords Antimalarial dyes; Brilliant green; Drug uptake; Food dyes; Transmission blocking; Triarylmethanes  
  Abstract The search for safe antimalarial compounds acting against asexual symptom-responsible stages and sexual transmission-responsible forms of Plasmodium species is one of the major challenges in malaria elimination programs. So far, among current drugs approved for human use, only primaquine has transmission-blocking activity. The discovery of small molecules targeting different Plasmodium falciparum life stages remains a priority in antimalarial drug research. In this context, several independent studies have recently reported antiplasmodial and transmission-blocking activities of commonly used stains, dyes and fluorescent probes against P. falciparum including chloroquine-resistant isolates. Herein we have studied the antimalarial activities of dyes with different scaffold and we report that the triarylmethane dye (TRAM) Brilliant green inhibits the growth of asexual stages (IC50 ≤ 2 μM) and has exflagellation-blocking activity (IC50 ≤ 800 nM) against P. falciparum reference strains (3D7, 7G8) and chloroquine-resistant clinical isolate (Q206). In a second step we have investigated the antiplasmodial activities of two polysulfonated triarylmethane food dyes. Green S (E142) is weakly active against P. falciparum asexual stage (IC50 ≃ 17 μM) whereas Patent Blue V (E131) is inactive in both antimalarial assays. By applying liquid chromatography techniques for the culture supernatant analysis after cell washings and lysis, we report the detection of Brilliant green in erythrocytes, the selective uptake of Green S (E142) by infected erythrocytes, whereas Patent Blue V (E131) could not be detected within non-infected and 3D7-infected erythrocytes. Overall, our results suggest that two polysulfonated food dyes might display different affinity with transporters or channels on infected RBC membrane. © 2017 The Authors  
  Address Research Unit of Genetics and Genomics of Insect Vectors Institut Pasteur, Paris, France  
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  Notes Export Date: 18 September 2017 Approved no  
  Call Number EcoFoG @ webmaster @ Serial (up) 765  
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Author Ploton, P.; Barbier, N.; Couteron, P.; Antin, C.M.; Ayyappan, N.; Balachandran, N.; Barathan, N.; Bastin, J.-F.; Chuyong, G.; Dauby, G.; Droissart, V.; Gastellu-Etchegorry, J.-P.; Kamdem, N.G.; Kenfack, D.; Libalah, M.; Mofack, G., II; Momo, S.T.; Pargal, S.; Petronelli, P.; Proisy, C.; Réjou-Méchain, M.; Sonké, B.; Texier, N.; Thomas, D.; Verley, P.; Zebaze Dongmo, D.; Berger, U.; Pélissier, R. url  doi
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  Title Toward a general tropical forest biomass prediction model from very high resolution optical satellite images Type Journal Article
  Year 2017 Publication Remote Sensing of Environment Abbreviated Journal  
  Volume 200 Issue Pages 140-153  
  Keywords Canopy structure; Forest carbon; Fourier transform; Lacunarity; Passive optical imagery; Redd; Texture; Tropical forests  
  Abstract Very high spatial resolution (VHSR) optical satellite imagery has shown good potential to provide non-saturating proxies of tropical forest aboveground biomass (AGB) from the analysis of canopy texture, for instance through the Fourier Transform Textural Ordination method. Empirical case studies however showed that the relationship between Fourier texture features and forest AGB varies across forest types and regions of the world, limiting model transferability. A better understanding of the biophysical mechanisms on which canopy texture – forest AGB relation relies is a prerequisite to move toward broad scale applications. Here we simulated VHSR optical canopy scenes in identical sun-sensor geometry for 279 1-ha tropical forest inventory plots distributed across the tropics. Our aim was to assess the respective merits and complementarity of two types of texture analysis techniques (i.e. Fourier and lacunarity) on a set of forests with contrasted structure and geographical origin, and develop a general texture-based approach for tropical forest AGB mapping. Across forests, Fourier texture captured a gradient of stands mean crown size reflecting well the progressive changes in stand structure throughout forest aggradation phase (e.g. Pearson's r = − 0.42 with basal area) while lacunarity texture captured a gradient of canopy openness (, i.e. Pearson's r = − 0.57 with stand gap fraction). Both types of texture indices were highly complementary for predicting forest AGB at the global level (so-called FL-model). The residual error of the FL-model was structured across sites and could be partially captured with a bioclimatic proxy, further improving the performance of the global model (so-called FLE-model) and reducing site-level biases. The FLE model was tested on a set of real Pleiades images covering a mosaic of high-biomass forests in the Congo basin (mean AGB over 49 field plots: 359 ± 98 Mg ha− 1), leading to a significant relationship (R2 = 0.47 on validation data) with reasonable error levels (< 25% rRMSE). The increasing availability of VHSR optical sensors (such as from constellations of small satellite platforms) raises the possibility of routine repeated imaging of the world's tropical forests and suggests that texture-based analyses could become an essential tool in international efforts to monitor carbon emissions from deforestation and forest degradations (REDD +). © 2017 Elsevier Inc.  
  Address Technische Universität Dresden, Faculty of Environmental Sciences, Institute of Forest Growth and Forest Computer Sciences, Tharandt, Germany  
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  Notes Export Date: 25 September 2017 Approved no  
  Call Number EcoFoG @ webmaster @ Serial (up) 766  
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Author Leroy, C.; Jauneau, A.; Martinez, Y.; Cabin-Flaman, A.; Gibouin, D.; Orivel, J.; Séjalon-Delmas, N. doi  openurl
  Title Exploring fungus-plant N transfer in a tripartite ant-plant-fungus mutualism Type Journal Article
  Year 2017 Publication Annals of Botany Abbreviated Journal Annals of Botany  
  Volume 120 Issue 3 Pages 417-426  
  Keywords Ascomycetes; endophytic fungi; Hirtella physophora; microscopy; mutualism; myrmecophyte; NanoSIMS; stable isotope  
  Abstract Background and Aims The plant Hirtella physophora, the ant Allomerus decemarticulatus and a fungus, Trimmatostroma sp., form a tripartite association. The ants manipulate both the plant trichomes and the fungus to build galleries under the stems of their host plant used to capture prey. In addition to its structural role, the fungus also improves nutrient uptake by the host plant. But it still remains unclear whether the fungus plays an indirect or a direct role in transferring nutrients to the plant. This study aimed to trace the transfer of N from the fungus to the plant's stem tissue. • Methods Optical microscopy and transmission electron microscopy (TEM) were used to investigate the presence of fungal hyphae in the stem tissues. Then, a 15N-labelling experiment was combined with a nanoscale secondary-ion mass spectrometry (NanoSIMS 50) isotopic imaging approach to trace the movement of added 15N from the fungus to plant tissues. • Key Results The TEM images clearly showed hyphae inside the stem tissue in the cellular compartment. Also, fungal hyphae were seen perforating the wall of the parenchyma cell. The 15N provisioning of the fungus in the galleries resulted in significant enrichment of the 15N signature of the plant's leaves 1 d after the 15N-labelling solution was deposited on the fungus-bearing trap. Finally, NanoSIMS imaging proved that nitrogen was transferred biotrophically from the fungus to the stem tissue. • Conclusions This study provides evidence that the fungi are connected endophytically to an ant-plant system and actively transfer nitrogen from 15N-labelling solution to the plant's stem tissues. Overall, this study underlines how complex the trophic structure of ant-plant interactions is due to the presence of the fungus and provides insight into the possibly important nutritional aspects and tradeoffs involved in myrmecophyte-ant mutualisms. © The Author 2017.  
  Address Laboratoire de Recherches en Sciences Végétales, Université de Toulouse, CNRS, UPS, France  
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  Notes Export Date: 2 October 2017 Approved no  
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Author Dejean, A.; Petitclerc, F.; Compin, A.; Azémar, F.; Corbara, B.; Delabie, J.H.C.; Leroy, C. url  doi
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  Title Hollow internodes permit a neotropical understory plant to shelter multiple mutualistic ant species, obtaining protection and nutrient provisioning (myrmecotrophy) Type Journal Article
  Year 2017 Publication American Naturalist Abbreviated Journal American Naturalist  
  Volume 190 Issue 5 Pages E124-E131  
  Keywords Ant-plant relationships; Biotic protection; Mutualism; Myrmecotrophy; Stable isotopes; Tachia guianensis  
  Abstract The Neotropical understory plant Tachia guianensis (Gentianaceae)- known to shelter the colonies of several ant species in its hollow trunks and branches-does not provide them with food rewards (e.g., extrafloral nectar). We tested whether these ants are opportunistic nesters or whether mutualistic relationships exist as for myrmecophytes or plants sheltering ant colonies in specialized hollow structures in exchange for protection from enemies and/or nutrient provisioning (myrmecotrophy). We noted 37 ant species sheltering inside T. guianensis internodes, three of them accounting for 43.5% of the cases. They protect their host plants from leaf-cutting ant defoliation and termite damage because individuals devoid of associated ants suffered significantly more attacks. Using the stable isotope 15N, we experimentally showed that the tested ant species furnish their host plants with nutrients. Therefore, a mutualism exists. However, because it is associated with numerous ant species, T. guianensis can be considered a nonspecialized myrmecophyte. © 2017 by The University of Chicago.  
  Address Institut de Recherche pour le Développement, UMR botAnique et Modélisation de l’Archtecture des Plantes et des Végétations, Cirad, CNRS, INRA, Université de Montpellier, Boulevard de la Lironde, TA A-51/PS2, Montpellier cedex 5, Brazil  
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  Notes Export Date: 2 November 2017 Approved no  
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Author Buckland, S.T.; Yuan, Y.; Marcon, E. pdf  url
doi  openurl
  Title Measuring temporal trends in biodiversity Type Journal Article
  Year 2017 Publication AStA Advances in Statistical Analysis Abbreviated Journal AStA Advances in Statistical Analysis  
  Volume 101 Issue 4 Pages 461-474  
  Keywords Biodiversity measures; Diversity profiles; Geometric mean; Species similarity; Turnover measures  
  Abstract In 2002, nearly 200 nations signed up to the 2010 target of the Convention for Biological Diversity, ‘to significantly reduce the rate of biodiversity loss by 2010’. To assess whether the target was met, it became necessary to quantify temporal trends in measures of diversity. This resulted in a marked shift in focus for biodiversity measurement. We explore the developments in measuring biodiversity that was prompted by the 2010 target. We consider measures based on species proportions, and also explain why a geometric mean of relative abundance estimates was preferred to such measures for assessing progress towards the target. We look at the use of diversity profiles, and consider how species similarity can be incorporated into diversity measures. We also discuss measures of turnover that can be used to quantify shifts in community composition arising, for example, from climate change. © 2017, The Author(s).  
  Address UMR EcoFoG, AgroParisTech, Campus Agronomique, BP 316, Kourou, French Guiana, France  
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  Notes Cited By :1; Export Date: 2 November 2017 Approved no  
  Call Number EcoFoG @ webmaster @ Serial (up) 769  
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Author Leroy, C.; Corbara, B.; Dezerald, O.; Trzcinski, M.K.; Carrias, J.-F.; Dejean, A.; Céréghino, R. url  doi
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  Title What drives detrital decomposition in neotropical tank bromeliads? Type Journal Article
  Year 2017 Publication Hydrobiologia Abbreviated Journal Hydrobiologia  
  Volume 802 Issue 1 Pages 85-95  
  Keywords Context dependency; Ecosystem function; Food webs; Leaf litter; Phytotelmata; Rainforest  
  Abstract Decomposition experiments that control leaf litter species across environments help to disentangle the roles of litter traits and consumer diversity, but once we account for leaf litter effects, they tell us little about the variance in decomposition explained by shifts in environmental conditions versus food-web structure. We evaluated how habitat, food-web structure, leaf litter species, and the interactions between these factors affect litter mass loss in a neotropical ecosystem. We used water-filled bromeliads to conduct a reciprocal transplant experiment of two litter species between an open and a forested habitat in French Guiana, and coarse- and fine-mesh enclosures embedded within bromeliads to exclude invertebrates or allow them to colonize leaf litter disks. Soft Melastomataceae leaves decomposed faster in their home habitat, whereas tough Eperua leaves decomposed equally in both habitats. Bacterial densities did not differ significantly between the two habitats. Significant shifts in the identity and biomass of invertebrate detritivores across habitats did not generate differences in leaf litter decomposition, which was essentially microbial. Despite the obvious effects of habitats on food-web structure, ecosystem processes are not necessarily affected. Our results pose the question of when does environmental determinism matter for ecosystem functions, and when does it not. © 2017, Springer International Publishing Switzerland.  
  Address IRD – UMR AMAP, Campus agronomique, BP 316, Kourou Cedex, France  
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  Notes Export Date: 18 December 2017 Approved no  
  Call Number EcoFoG @ webmaster @ Serial (up) 775  
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Author Talaga, S.; Dezerald, O.; Carteron, A.; Leroy, C.; Carrias, J.-F.; Céréghino, R.; Dejean, A. url  doi
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  Title Urbanization impacts the taxonomic and functional structure of aquatic macroinvertebrate communities in a small Neotropical city Type Journal Article
  Year 2017 Publication Urban Ecosystems Abbreviated Journal Urban Ecosystems  
  Volume 20 Issue 5 Pages 1001-1009  
  Keywords Aedes aegypti; Bioindicator; Diversity; Functional traits; Tank bromeliads; Urban ecology  
  Abstract Due to habitat fragmentation, resource disruption and pollution, urbanization is one of the most destructive forms of anthropization affecting ecosystems worldwide. Generally, human-mediated perturbations dramatically alter species diversity in urban sites compared to the surroundings, thus influencing the functioning of the entire ecosystem. We investigated the taxonomic and functional diversity patterns of the aquatic macroinvertebrate communities in tank bromeliads by comparing those found in a small Neotropical city with those from an adjacent rural site. Changes in the quality of detrital inputs in relation to lower tree diversity and the presence of synanthropic species are likely important driving forces behind the observed structural changes in the urban site. Leaf-litter processors (i.e., shredders, scrapers) were positively affected in the urban site, while filter-feeders that process smaller particles produced by the activity of the shredders were negatively affected. Because we cannot ascertain whether the decline in filter-feeders is related to food web-mediated effects or to competitive exclusion (Aedes aegypti mosquitoes were present in urban bromeliads only), further studies are necessary to account for the effects of intra-guild competition or inter-guild facilitation. © 2017, Springer Science+Business Media New York.  
  Address Ecolab, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France  
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  Notes Cited By :1; Export Date: 18 December 2017 Approved no  
  Call Number EcoFoG @ webmaster @ Serial (up) 776  
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Author Talaga, S.; Petitclerc, F.; Carrias, J.-F.; Dezerald, O.; Leroy, C.; Céréghino, R.; Dejean, A. url  doi
openurl 
  Title Environmental drivers of community diversity in a neotropical urban landscape: a multi-scale analysis Type Journal Article
  Year 2017 Publication Landscape Ecology Abbreviated Journal Landscape Ecology  
  Volume 32 Issue 9 Pages 1805-1818  
  Keywords Aquatic metacommunity; Landscape ecology; Mosquitoes; Neotropics; Scale dependency; Tank bromeliads; Urban ecology  
  Abstract Context: Many aquatic communities are linked by the aerial dispersal of multiple, interacting species and are thus structured by processes occurring in both the aquatic and terrestrial compartments of the ecosystem. Objectives: To evaluate the environmental factors shaping the aquatic macroinvertebrate communities associated with tank bromeliads in an urban landscape. Methods: Thirty-two bromeliads were georeferenced to assess the spatial distribution of the aquatic meta-habitat in one city. The relative influence of the aquatic and terrestrial habitats on the structure of macroinvertebrate communities was analyzed at four spatial scales (radius = 10, 30, 50, and 70 m) using redundancy analyses. Results: We sorted 18,352 aquatic macroinvertebrates into 29 taxa. Water volume and the amount of organic matter explained a significant part of the taxa variance, regardless of spatial scale. The remaining variance was explained by the meta-habitat size (i.e., the water volume for all of the bromeliads within a given surface area), the distance to the nearest building at small scales, and the surface area of buildings plus ground cover at larger scales. At small scales, the meta-habitat size influenced the two most frequent mosquito species in opposite ways, suggesting spatial competition and coexistence. Greater vegetation cover favored the presence of a top predator. Conclusions: The size of the meta-habitat and urban landscape characteristics influence the structure of aquatic communities in tank bromeliads, including mosquito larval abundance. Modifications to this landscape will affect both the terrestrial and aquatic compartments of the urban ecosystem, offering prospects for mosquito management during urban planning. © 2017, Springer Science+Business Media B.V.  
  Address IRD; UMR AMAP (botAnique et Modélisation de l’Architecture des Plantes et des végétations), Boulevard de la Lironde, TA A‐51/PS2, Montpellier Cedex 5, France  
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  Notes Export Date: 18 December 2017 Approved no  
  Call Number EcoFoG @ webmaster @ Serial (up) 777  
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Author Roux, O.; Vantaux, A.; Petitclerc, F.; Orivel, J.; Dejean, A.; Billen, J. url  doi
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  Title Structural adaptations and mechanism of reflex bleeding in the larvae of the myrmecophilous ladybird Diomus thoracicus Type Journal Article
  Year 2017 Publication Arthropod Structure and Development Abbreviated Journal Arthropod Structure and Development  
  Volume 46 Issue 4 Pages 529-536  
  Keywords 3D reconstruction; Coccinellidae; Myrmecophagous insect; Reflex bleeding; Ultrastructure  
  Abstract Reflex bleeding is an effective defensive mechanism against predators. When attacked, some insects emit hemolymph, which coagulates, quickly entangling their aggressor. Bleeding occurs at weak intersegmental membranes or through dedicated organs, which can be associated or not with glandular cells. Here, we describe the behavior and morphological structures involved in reflex bleeding in the larvae of the ladybird, Diomus thoracicus, which are intranidal parasites of the ant Wasmannia auropunctata. The larvae are tolerated by the ants thanks to odor mimicry, but some rare aggressive ant behaviors were observed that trigger reflex bleeding both at a pair of thoracic tubercles and a pair of posterodorsal abdominal humps. No glandular structure was found in association with these emission points, which suggests that the material emitted was hemolymph only. A 3D reconstruction suggested that reflex bleeding seems to be controlled by muscles whose contraction increases the internal hydrostatic pressure and pushes the hemolymph into a funnel-like structure with an opening to the outside. In D. thoracicus, the morphological structures involved in reflex bleeding are among the most complex and prominent described to date. © 2017 Elsevier Ltd  
  Address KU Leuven, Zoological Institute, Naamsestraat 59, box 2466, Leuven, Belgium  
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  Notes Export Date: 18 December 2017 Approved no  
  Call Number EcoFoG @ webmaster @ Serial (up) 778  
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