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Author Talaga, S.; Dejean, A.; Mouza, C.; Dumont, Y.; Leroy, C.
Title (up) Larval interference competition between the native Neotropical mosquito Limatus durhamii and the invasive Aedes aegypti improves the fitness of both species Type Journal Article
Year 2018 Publication Insect Science Abbreviated Journal Insect Science
Volume 25 Issue Pages 1102-1107
Keywords Aedes aegypti; increased fitness; interference competition; Limatus durhamii; phenotypic plasticity; resistance to invasion
Abstract Abstract Interspecific competition with native species during biological invasions can sometimes limit alien expansion. We aimed to determine the potential ecological effects of Limatus durhamii Theobald 1901, a native Neotropical mosquito (Diptera: Culicidae) species, on the invasive species Aedes (Stegomyia) aegypti (Linnaeus 1762) that breeds in the same artificial water containers. Development time and adult dry mass were measured in 3 rearing conditions: control (a single larva), intraspecific competition (2 conspecific larvae), and interspecific competition (2 heterospecific larvae). Food was provided ad libitum to eliminate exploitative competition. For Ae. aegypti, development time was not affected by interspecific interference competition (nonsignificant differences with the control) and the adult dry mass was significantly higher, meaning that individual fitness likely increased. Yet, because previous studies showed longer development time and lighter adults during competition with other invasive mosquitoes, it is likely that Ae. aegypti can express a different phenotype depending on the competing species. The similar pattern found for Li. durhamii females and the nonsignificant difference with the control for males explain in part why this species can compete with Ae. aegypti.
Address
Corporate Author Thesis
Publisher John Wiley & Sons, Ltd (10.1111) Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1672-9609 ISBN Medium
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Notes Approved no
Call Number EcoFoG @ webmaster @ Serial 836
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Author Nirma, C.; Rodrigues, A.M.S.; Basset, C.; Chevolot, L.; Girod, R.; Moretti, C.; Stien, D.; Dusfour, I.; Eparvier, V.
Title (up) Larvicidal activity of isoflavonoids from Muellera frutescens extracts against Aedes aegypti Type Journal Article
Year 2012 Publication Natural Product Communications Abbreviated Journal
Volume 7 Issue 10 Pages 1319-1322
Keywords Aedes aegypti; French Guiana; Insecticides; Isoflavonoids; Muellera frutescens
Abstract The biological activity of extracts from the leaves, bark and roots of Muellera frutescens, an Amazonian ichtyotoxic plant, were evaluated to find new environmentally safe insecticides. The n-hexane extracts of bark, leaf, and root showed a strong toxic activity against Aedes aegypti mosquito larvae. Bioguided fractionation of the bark extract led to the isolation of seven isoflavonoids (12a-hydroxyelliptone, elliptone, (-)-variabilin, rotenone, rotenolone, tephrosin and deguelin). Rotenone and deguelin are responsible for the larvicidal activity of the plant. M. frutescens leaves contain up to 0.6%, w/w, deguelin. These results justify the traditional ichtyotoxic use of M. frutescens. The leaves contain a relatively high proportion of deguelin and, therefore, can be considered as a renewable source of this environmentally friendly insecticidal isoflavonoid.
Address CNRS, Institut de Chimie des Substances Naturelles, UPR 2301, 1 avenue de la Terrasse, 91198 Gif-sur-Yvette, France
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Notes Export Date: 6 December 2012; Source: Scopus Approved no
Call Number EcoFoG @ webmaster @ Serial 448
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Author Sommeria-Klein, G.; Zinger, L.; Coissac, E.; Iribar, A.; Schimann, H.; Taberlet, P.; Chave, J.
Title (up) Latent Dirichlet Allocation reveals spatial and taxonomic structure in a DNA-based census of soil biodiversity from a tropical forest Type Journal Article
Year 2020 Publication Molecular Ecology Resources Abbreviated Journal Mol. Ecol. Resour.
Volume 20 Issue 2 Pages 371-386
Keywords community ecology; environmental DNA; metabarcoding; OTU presence–absence; soil microbiome; topic modelling; bacterium; biodiversity; biology; classification; eukaryote; fungus; genetics; high throughput sequencing; isolation and purification; microbiology; parasitology; procedures; soil; Bacteria; Biodiversity; Computational Biology; Eukaryota; Fungi; High-Throughput Nucleotide Sequencing; Soil; Soil Microbiology
Abstract High-throughput sequencing of amplicons from environmental DNA samples permits rapid, standardized and comprehensive biodiversity assessments. However, retrieving and interpreting the structure of such data sets requires efficient methods for dimensionality reduction. Latent Dirichlet Allocation (LDA) can be used to decompose environmental DNA samples into overlapping assemblages of co-occurring taxa. It is a flexible model-based method adapted to uneven sample sizes and to large and sparse data sets. Here, we compare LDA performance on abundance and occurrence data, and we quantify the robustness of the LDA decomposition by measuring its stability with respect to the algorithm's initialization. We then apply LDA to a survey of 1,131 soil DNA samples that were collected in a 12-ha plot of primary tropical forest and amplified using standard primers for bacteria, protists, fungi and metazoans. The analysis reveals that bacteria, protists and fungi exhibit a strong spatial structure, which matches the topographical features of the plot, while metazoans do not, confirming that microbial diversity is primarily controlled by environmental variation at the studied scale. We conclude that LDA is a sensitive, robust and computationally efficient method to detect and interpret the structure of large DNA-based biodiversity data sets. We finally discuss the possible future applications of this approach for the study of biodiversity. © 2019 John Wiley & Sons Ltd
Address Laboratoire d’Ecologie des Forêts de Guyane (EcoFoG, UMR 745), INRA, AgroParisTech, CIRAD, CNRS, University of the French West Indies, University of French Guiana, Kourou, France
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 1755098x (Issn) ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number EcoFoG @ webmaster @ Serial 981
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Author Bonal, D.; Ponton, S.; Le Thiec, D.; Richard, B.; Ningre, N.; Herault, B.; Ogee, J.; Gonzalez, S.; Pignal, M.; Sabatier, D.; Guehl, J.M.
Title (up) Leaf functional response to increasing atmospheric CO(2) concentrations over the last century in two northern Amazonian tree species: a historical delta(13)C and delta(18)O approach using herbarium samples Type Journal Article
Year 2011 Publication Plant Cell and Environment Abbreviated Journal Plant Cell Environ.
Volume 34 Issue 8 Pages 1332-1344
Keywords carbon isotope composition; environmental change; herbarium; oxygen isotope composition; photosynthesis; stomata; tropical rainforests
Abstract We assessed the extent of recent environmental changes on leaf morphological (stomatal density, stomatal surface, leaf mass per unit area) and physiological traits (carbon isotope composition, delta(13)C(leaf), and discrimination, Delta(13)C(leaf), oxygen isotope composition, delta(18)O(leaf)) of two tropical rainforest species (Dicorynia guianensis; Humiria balsamifera) that are abundant in the Guiana shield (Northern Amazonia). Leaf samples were collected in different international herbariums to cover a 200 year time-period (1790-2004) and the whole Guiana shield. Using models describing carbon and oxygen isotope fractionations during photosynthesis, different scenarios of change in intercellular CO(2) concentrations inside the leaf (C(i)), stomatal conductance (g), and photosynthesis (A) were tested in order to understand leaf physiological response to increasing air CO(2) concentrations (C(a)). Our results confirmed that both species displayed physiological response to changing C(a). For both species, we observed a decrease of about 1.7% in delta(13)C(leaf) since 1950, without significant change in Delta(13)C(leaf) and leaf morphological traits. Furthermore, there was no clear change in delta(18)O(leaf) for Humiria over this period. Our simulation approach revealed that an increase in A, rather than a decrease in g, explained the observed trends for these tropical rainforest species, allowing them to maintain a constant ratio of C(i)/C(a).
Address [Bonal, D] INRA, UMR Ecofog, F-97387 Kourou, France, Email: bonal@nancy.inra.fr
Corporate Author Thesis
Publisher Wiley-Blackwell Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0140-7791 ISBN Medium
Area Expedition Conference
Notes WOS:000292698900010 Approved no
Call Number EcoFoG @ webmaster @ Serial 330
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Author Coste, S.; Roggy, J.C.; Imbert, P.; Born, C.; Bonal, D.; Dreyer, E.
Title (up) Leaf photosynthetic traits of 14 tropical rain forest species in relation to leaf nitrogen concentration and shade tolerance Type Journal Article
Year 2005 Publication Tree Physiology Abbreviated Journal Tree Physiol.
Volume 25 Issue 9 Pages 1127-1137
Keywords functional diversity; leaf carbon; leaf nitrogen; nitrogen-use efficiency; photosynthetic capacity; tropical rain forest
Abstract Variability of leaf traits related to photosynthesis was assessed in seedlings from 14 tree species growing in the tropical rain forest of French Guiana. Leaf photosynthetic capacity (maximum rate of carboxylation and maximum rate of electron transport) was estimated by fitting a biochemical model of photosynthesis to response curves of net CO2 assimilation rate versus intercellular CO2 mole fraction. Leaf morphology described by leaf mass per unit leaf area (LMA), density and thickness, as well as area- and mass-based nitrogen (N) and carbon (C) concentrations, were recorded on the same leaves. Large interspecific variability was detected in photosynthetic capacity as well as in leaf structure and leaf N and C concentrations. No correlation was found between leaf thickness and density. The correlations between area- and mass-based leaf N concentration and photosynthetic capacity were poor. Conversely, the species differed greatly in relative N allocation to carboxylation and bioenergetics. Principal component analysis (PCA) revealed that, of the recorded traits, only the computed fraction of total leaf N invested in photosynthesis was tightly correlated to photosynthetic capacity. We also used PCA to test to what extent species with similar shade tolerances displayed converging leaf traits related to photosynthesis. No clear-cut ranking could be detected among the shade-tolerant groups, as confirmed by a one-way ANOVA. We conclude that the large interspecific diversity in photosynthetic capacity was mostly explained by differences in the relative allocation of N to photosynthesis and not by leaf N concentration, and that leaf traits related to photosynthetic capacity did not discriminate shade-tolerance ranking of these tropical tree species.
Address CNRS Ecol Forets Guyane, INRA, ENGREF,CIRAD, Unite Mixte Rech, Kourou 97387, French Guiana, Email: roggy.j@cirad.fr
Corporate Author Thesis
Publisher HERON PUBLISHING Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0829-318X ISBN Medium
Area Expedition Conference
Notes ISI:000231555200005 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 230
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Author Lamarre, G.P.A.; Mendoza, I.; Fine, P.V.A.; Baraloto, C.
Title (up) Leaf synchrony and insect herbivory among tropical tree habitat specialists Type Journal Article
Year 2014 Publication Plant Ecology Abbreviated Journal Plant Ecol.
Volume 215 Issue 2 Pages 209-220
Keywords Escape; French Guiana; Herbivorous insects; Phenology; Resource availability; Time lag
Abstract Growth defense tradeoff theory predicts that plants in low-resource habitats invest more energy in defense mechanisms against natural enemies than growth, whereas plants in high-resource habitats can afford higher leaf loss rates. A less-studied defense against herbivores involves the synchrony of leaf production, which can be an effective defense strategy if leaf biomass production exceeds the capacity of consumption by insects. The aim of this study was to determine whether leaf synchrony varied across habitats with different available resources and whether insects were able to track young leaf production among tree habitat specialists in a tropical forest of French Guiana. We predicted that high-resource habitats would exhibit more synchrony in leaf production due to the low cost and investment to replace leaf tissue. We also expected closer patterns of leaf synchrony and herbivory within related species, assuming that they shared herbivores. We simultaneously monitored leaf production and herbivory rates of five pairs of tree species, each composed of a specialist of terra firme or white-sand forests within the same lineage. Our prediction was not supported by the strong interaction of habitat and lineage for leaf synchrony within individuals of the same species; although habitat specialists differed in leaf synchrony within four of five lineages, the direction of the effect was variable. All species showed short time lags for the correlation between leaf production and herbivory, suggesting that insects are tightly tracking leaf production, especially for the most synchronous species. Leaf synchrony may provide an important escape defense against herbivores, and its expression appears to be constrained by both evolutionary history and environmental factors. © 2014 Springer Science+Business Media Dordrecht.
Address Department of Biology, University of Florida, Gainesville, FL, 32611, United States
Corporate Author Thesis
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ISSN 13850237 (Issn) ISBN Medium
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Notes Export Date: 24 February 2014; Source: Scopus; Coden: Plecf; Language of Original Document: English; Correspondence Address: Lamarre, G. P. A.; Université Antilles Guyane, UMR Ecologie des Forêts de Guyane, 97310 Kourou, French Guiana; email: greglamarre973@gmail.com; Funding Details: DEB-0743103/0743800, NSF, National Science Foundation Approved no
Call Number EcoFoG @ webmaster @ Serial 530
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Author Haettenschwiler, S.; Coq, S.; Barantal, S.; Handa, I.T.
Title (up) Leaf traits and decomposition in tropical rainforests: revisiting some commonly held views and towards a new hypothesis Type Journal Article
Year 2011 Publication New Phytologist Abbreviated Journal New Phytol.
Volume 189 Issue 4 Pages 950-965
Keywords energy starvation; French Guiana; litter quality; mycorrhizas; nutrient cycling; nutrient limitation; phosphorus; soil fauna
Abstract Proper estimates of decomposition are essential for tropical forests, given their key role in the global carbon (C) cycle. However, the current paradigm for litter decomposition is insufficient to account for recent observations and may limit model predictions for highly diverse tropical ecosystems. In light of recent findings from a nutrient-poor Amazonian rainforest, we revisit the commonly held views that: litter traits are a mere legacy of live leaf traits; nitrogen (N) and lignin are the key litter traits controlling decomposition; and favourable climatic conditions result in rapid decomposition in tropical forests. Substantial interspecific variation in litter phosphorus (P) was found to be unrelated to variation in green leaves. Litter nutrients explained no variation in decomposition, which instead was controlled primarily by nonlignin litter C compounds at low concentrations with important soil fauna effects. Despite near-optimal climatic conditions, tropical litter decomposition proceeded more slowly than in a climatically less favourable temperate forest. We suggest that slow decomposition in the studied rainforest results from a syndrome of poor litter C quality beyond a simple lignin control, enforcing energy starvation of decomposers. We hypothesize that the litter trait syndrome in nutrient-poor tropical rainforests may have evolved to increase plant access to limiting nutrients via mycorrhizal associations.
Address [Haettenschwiler, Stephan; Coq, Sylvain; Barantal, Sandra; Handa, Ira Tanya] CNRS, CEFE, F-34293 Montpellier 5, France, Email: stephan.hattenschwiler@cefe.cnrs.fr
Corporate Author Thesis
Publisher Wiley-Blackwell Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0028-646x ISBN Medium
Area Expedition Conference
Notes ISI:000286940500009 Approved no
Call Number EcoFoG @ webmaster @ Serial 296
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Author Fortunel, C.; Garnier, E.; Joffre, R.; Kazakou, E.; Quested, H.; Grigulis, K.; Lavorel, S.; Ansquer, P.; Castro, H.; Cruz, P.; Dolezal, J.; Eriksson, O.; Freitas, H.; Golodets, C.; Jouany, C.; Kigel, J.; Kleyer, M.; Lehsten, V.; Leps, J.; Meier, T.; Pakeman, R.; Papadimitriou, M.; Papanastasis, V.P.; Quetier, F.; Robson, M.; Sternberg, M.; Theau, J.P.; Thebault, A.; Zarovali, M.
Title (up) Leaf traits capture the effects of land use changes and climate on litter decomposability of grasslands across Europe Type Journal Article
Year 2009 Publication Ecology Abbreviated Journal Ecology
Volume 90 Issue 3 Pages 598-611
Keywords climate; community functional parameters; disturbance; leaf traits; litter decomposability; litter quality
Abstract Land use and climate changes induce shifts in plant functional diversity and community structure, thereby modifying ecosystem processes. This is particularly true for litter decomposition, an essential process in the biogeochemical cycles of carbon and nutrients. In this study, we asked whether changes in functional traits of living leaves in response to changes in land use and climate were related to rates of litter potential decomposition, hereafter denoted litter decomposability, across a range of 10 contrasting sites. To disentangle the different control factors on litter decomposition, we conducted a microcosm experiment to determine the decomposability under standard conditions of litters collected in herbaceous communities from Europe and Israel. We tested how environmental factors ( disturbance and climate) affected functional traits of living leaves and how these traits then modified litter quality and subsequent litter decomposability. Litter decomposability appeared proximately linked to initial litter quality, with particularly clear negative correlations with lignin-dependent indices ( litter lignin concentration, lignin : nitrogen ratio, and fiber component). Litter quality was directly related to community-weighted mean traits. Lignin-dependent indices of litter quality were positively correlated with community-weighted mean leaf dry matter content (LDMC), and negatively correlated with community-weighted mean leaf nitrogen concentration (LNC). Consequently, litter decomposability was correlated negatively with community-weighted mean LDMC, and positively with community-weighted mean LNC. Environmental factors ( disturbance and climate) influenced community-weighted mean traits. Plant communities experiencing less frequent or less intense disturbance exhibited higher community-weighted mean LDMC, and therefore higher litter lignin content and slower litter decomposability. LDMC therefore appears as a powerful marker of both changes in land use and of the pace of nutrient cycling across 10 contrasting sites.
Address [Fortunel, Claire; Garnier, Eric; Joffre, Richard; Kazakou, Elena] CNRS, UMR 5175, Ctr Ecol Fonct & Evolut, F-34293 Montpellier 5, France, Email: claire.fortunel@ecofog.gf
Corporate Author Thesis
Publisher ECOLOGICAL SOC AMER Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0012-9658 ISBN Medium
Area Expedition Conference
Notes ISI:000263776800003 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 121
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Author Fortunel, C.; Fine, P.V.A.; Baraloto, C.
Title (up) Leaf, stem and root tissue strategies across 758 Neotropical tree species Type Journal Article
Year 2012 Publication Functional Ecology Abbreviated Journal Funct. Ecol.
Volume 26 Issue 5 Pages 1153-1161
Keywords French Guiana; Functional trade-offs; Leaf economics; Peru; Plant traits; Tropical forest; Wood economics
Abstract 1. Trade-offs among functional traits reveal major plant strategies that can give insight into species distributions and ecosystem processes. However, current identification of plant strategies lacks the integration of root structural traits together with leaf and stem traits. 2. We examined correlations among 14 traits representing leaf, stem and woody root tissues. Traits were measured on 1084 individuals representing 758 Neotropical tree species, across 13 sites representative of the environmental variation encompassed by three widespread habitats (seasonally flooded, clay terra firme and white-sand forests) at opposite ends of Amazonia (French Guiana and Peru). 3. Woody root traits were closely aligned with stem traits, but not with leaf traits. Altogether leaf, stem and woody root traits delineated two orthogonal axes of functional trade-offs: a first axis defined by leaf traits, corresponding to a 'leaf economics spectrum', and a second axis defined by covarying stem and woody root traits, corresponding to a 'wood economics spectrum'. These axes remained consistent when accounting for species evolutionary history with phylogenetically independent contrasts. 4. Despite the strong species turnover across sites, the covariation among root and stem structural traits as well as their orthogonality to leaf traits were strongly consistent across habitats and regions. 5. We conclude that root structural traits mirrored stem traits rather than leaf traits in Neotropical trees. Leaf and wood traits define an integrated whole-plant strategy in lowland South American forests that may contribute to a more complete understanding of plant responses to global changes in both correlative and modelling approaches. We suggest further meta-analyses in expanded environmental and geographic zones to determine the generality of this pattern. © 2012 The Authors. Functional Ecology © 2012 British Ecological Society.
Address Department of Biology, University of Florida, Gainesville, FL, 32611, United States
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ISSN 02698463 (Issn) ISBN Medium
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Notes Export Date: 10 October 2012; Source: Scopus; Coden: Fecoe; doi: 10.1111/j.1365-2435.2012.02020.x; Language of Original Document: English; Correspondence Address: Fortunel, C.; INRA, UMR Ecologie des Forêts de Guyane, BP 709, 97387 Kourou Cedex, France; email: claire.fortunel@ecofog.gf Approved no
Call Number EcoFoG @ webmaster @ Serial 440
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Author Groc, S.; Delabie, J.H.C.; Fernández, F.; Leponce, M.; Orivel, J.; Silvestre, R.; Vasconcelos, H.L.; Dejean, A.
Title (up) Leaf-litter ant communities (Hymenoptera: Formicidae) in a pristine Guianese rain-forest: Stable functional structure versus high species turnover Type Journal Article
Year 2014 Publication Myrmecological News Abbreviated Journal Myrmecological News
Volume 19 Issue Pages 43-51
Keywords Diversity gradient; Functional groups; Habitat heterogeneity; Litter-dwelling ant communities; Local scale; Pristine Amazonian rainforest; Taxonomic and functional structure
Abstract We compared the ant assemblages from four very heterogeneous habitats over a short-distance elevational gradient of vegetation (due to the presence of an inselberg) at the Nouragues Research Station, French Guiana. We focused on litter-dwelling ants, combining the use of pitfall traps and the Winkler method according to the Ants of the Leaf Litter Proto-col. This permitted us to note (1) a high leaf-litter ant diversity overall and a decreasing diversity gradient from the lowland rainforest to the top of the inselberg, and (2) differences in species density, composition and functional struc-ture. While the ant assemblages on the plateau and inselberg can be considered functionally similar and typical of an Amazonian rainforest, that of the transition forest, relatively homogenous, rather corresponded to an ant fauna typical of open areas. By contrast, the liana forest assemblage was unexpectedly richer and denser than the others, sheltering a litter-dwelling ant fauna dominated by numerous and abundant cryptic species. These taxonomical and functional dissi-milarities may reflect the influence of the environmental heterogeneity, which, through variable abiotic conditions, can contribute to maintaining a notably rich ant biodiversity in these Neotropical habitats.
Address Université de Toulouse, UPS (Ecolab), 118 route de Narbonne, 31062 Toulouse Cedex 9, France
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ISSN 19944136 (Issn) ISBN Medium
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Notes Export Date: 10 March 2014; Source: Scopus; Language of Original Document: English; Correspondence Address: Groc, S.; Instituto de Biologia, Universidade Federal de Uberlândia (UFU), 38400-902 Uberlândia, Minas Gerais, Brazil; email: groc.sarah@gmail.com Approved no
Call Number EcoFoG @ webmaster @ Serial 534
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