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Author (up) Dezerald, O.; Céréghino, R.; Corbara, B.; Dejean, A.; Leroy, C. url  openurl
  Title Functional trait responses of aquatic macroinvertebrates to simulated drought in a Neotropical bromeliad ecosystem Type Journal Article
  Year 2015 Publication Freshwater Biology Abbreviated Journal Freshwater Biology  
  Volume 60 Issue 9 Pages 1917-1929  
  Keywords Food webs; Precipitations; Rainforests; Resistance/resilience; Tipping point  
  Abstract The duration of the dry seasons in south-eastern Amazonia is expected to increase. Little is known of how freshwater assemblages respond to drought in the humid rainforests and of the extent to which they resist the absence of rainfall before the collapse of the system. We manipulated rainshelters over tank-forming bromeliads (i.e. the interlocking leaf axils of these plants form wells that collect rainwater) to simulate an exceptionally long dry period (49 days, compared with a 10-year mean ± SD annual maximum number of 17 ± 5.3 days without rainfall at the study site) and then a rewetting period. By sampling weekly over 3 months, we followed the dynamics of the representation of abundance-weighted traits in invertebrate assemblages in these treatment plants and in a control group. The functional structure of assemblages was drought resistant until the water volume in the bromeliad pools dropped by 90%, when there was a sudden shift in the functional trait structure due to the loss of most populations except the drought-resistant culicids. Traits related to life history, body size and preferred food showed significant responses to drought. There was a convergence in the functional traits of species surviving in dry plants, strengthening the idea that environmental filtering, rather than stochasticity, determines the functional trajectory of aquatic assemblages during drought. At the end of the dry period, samples of the detritus potentially containing drought-resistant eggs/cysts (and eventually live larvae) were taken from the dry plants and rewetted in the laboratory, allowing us to distinguish resistant species from those requiring recolonisation via subsequent oviposition by adults from elsewhere. Patches of water-filled bromeliads persisting in the area provided the most important pool of colonists, and communities returned to the pre-disturbance state within 1-2 weeks of rewetting. Our results suggest that the functional trait structure of invertebrate assemblages in bromeliads could remain stable under scenarios of precipitation change that would triple the duration of current dry periods at a local scale. Future experiments should evaluate how environmental factors might alter the tipping point between resistance to drought and a collapse in ecosystem processes. © 2015 John Wiley & Sons Ltd.  
  Address IRD, UMR AMAP (botAnique et Modélisation de l'Architecture des Plantes et des vegetations), Boulevard de la Lironde, TA A-51/PS2, Montpellier Cedex 5, France  
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  Notes Export Date: 27 August 2015 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 616  
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Author (up) Dezerald, O.; Leroy, C.; Corbara, B.; Carrias, J.-F.; Pélozuelo, L.; Dejean, A.; Céréghino, R. pdf  url
openurl 
  Title Food-Web Structure in Relation to Environmental Gradients and Predator-Prey Ratios in Tank-Bromeliad Ecosystems Type Journal Article
  Year 2013 Publication PLoS ONE Abbreviated Journal PLoS ONE  
  Volume 8 Issue 8 Pages e71735  
  Keywords  
  Abstract Little is known of how linkage patterns between species change along environmental gradients. The small, spatially discrete food webs inhabiting tank-bromeliads provide an excellent opportunity to analyse patterns of community diversity and food-web topology (connectance, linkage density, nestedness) in relation to key environmental variables (habitat size, detrital resource, incident radiation) and predators:prey ratios. We sampled 365 bromeliads in a wide range of understorey environments in French Guiana and used gut contents of invertebrates to draw the corresponding 365 connectance webs. At the bromeliad scale, habitat size (water volume) determined the number of species that constitute food-web nodes, the proportion of predators, and food-web topology. The number of species as well as the proportion of predators within bromeliads declined from open to forested habitats, where the volume of water collected by bromeliads was generally lower because of rainfall interception by the canopy. A core group of microorganisms and generalist detritivores remained relatively constant across environments. This suggests that (i) a highly-connected core ensures food-web stability and key ecosystem functions across environments, and (ii) larger deviations in food-web structures can be expected following disturbance if detritivores share traits that determine responses to environmental changes. While linkage density and nestedness were lower in bromeliads in the forest than in open areas, experiments are needed to confirm a trend for lower food-web stability in the understorey of primary forests. © 2013 Dézerald et al.  
  Address EcoLab, Laboratoire Ecologie Fonctionnelle et Environnement, CNRS UMR 5245, Toulouse, France  
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  ISSN 19326203 (Issn) ISBN Medium  
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  Notes Export Date: 30 August 2013; Source: Scopus; Art. No.: e71735; Coden: Polnc; doi: 10.1371/journal.pone.0071735; Language of Original Document: English; Correspondence Address: Dézerald, O.; EcoFoG, Ecologie des Forêts de Guyane, CNRS UMR 8172, Kourou, France; email: olivier.dezerald@gmail.com Approved no  
  Call Number EcoFoG @ webmaster @ Serial 499  
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Author (up) Dezerald, O.; Leroy, C.; Corbara, B.; Dejean, A.; Talaga, S.; Céréghino, R. doi  openurl
  Title Environmental drivers of invertebrate population dynamics in Neotropical tank bromeliads Type Journal Article
  Year 2017 Publication Freshwater Biology Abbreviated Journal Freshw Biol  
  Volume 62 Issue 2 Pages 229-242  
  Keywords food webs; freshwater invertebrates; growth rate; life history; rainforest  
  Abstract Tank bromeliads form a conspicuous, yet neglected freshwater habitat in Neotropical forests. Recent studies driven by interests in medical entomology, fundamental aspects of bromeliad ecology and experimental research on food webs have, however, prompted increasing interest in bromeliad aquatic ecosystems. As yet, there is nothing in the literature about the life histories and environmental drivers of invertebrate population dynamics in tank bromeliads.

Based on fortnightly samples taken over one year, size frequency plots and individual dry masses allowed us to establish the life cycles and growth rates of the dominant aquatic invertebrates in a common bromeliad species of French Guiana. Linear mixed-effect models and Mantel tests were used to predict changes in density, biomass, and growth rates in relation to temperature, rainfall, humidity and detrital resources.

Annual variations in invertebrate densities and biomasses could be described according to three types of distribution: unimodal, bimodal or almost constant. Despite seasonal variations, precipitation, temperature, relative humidity and detritus concentration accounted significantly for changes in density and biomass, but we found no significant responses in growth rates of most invertebrate species. Species rather displayed non-seasonal life cycles with overlapping cohorts throughout the year. There was also a trend for delayed abundance peaks among congeneric species sharing similar functional traits, suggesting temporal partitioning of available resources.

Beyond novel knowledge, quantitative information on life histories is important to predict food-web dynamics under the influence of external forcing and self-organisation. Our results suggest that changes in species distribution that will affect population dynamics through biotic interactions in space and/or time could have greater effects on food webs and ecosystem functioning than changes in environmental factors per se.
 
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  ISSN 1365-2427 ISBN Medium  
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  Call Number EcoFoG @ webmaster @ Serial 716  
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Author (up) Dezerald, O.; Talaga, S.; Leroy, C.; Carrias, J.-F.; Corbara, B.; Dejean, A.; Céréghino, R. url  doi
openurl 
  Title Environmental determinants of macroinvertebrate diversity in small water bodies: Insights from tank-bromeliads Type Journal Article
  Year 2014 Publication Hydrobiologia Abbreviated Journal Hydrobiologia  
  Volume 723 Issue 1 Pages 77-86  
  Keywords Freshwater biodiversity; Linear mixed effect modelling; Microcosms; Phytotelmata; Ponds  
  Abstract The interlocking leaves of tank-forming bromeliads (Bromeliaceae) collect rainwater and detritus, thus creating a freshwater habitat for specialized organisms. Their abundance and the possibility of quantifying communities with accuracy give us unparalleled insight into how changes in local to regional environments influence community diversity in small water bodies. We sampled 365 bromeliads (365 invertebrate communities) along a southeastern to northwestern range in French Guiana. Geographic locality determined the species pool for bromeliad invertebrates, and local environments determined the abundance patterns through the selection of traits that are best adapted to the bromeliad habitats. Patterns in community structure mostly emerged from patterns of predator species occurrence and abundance across local-regional environments, while the set of detritivores remained constant. Water volume had a strong positive correlation with invertebrate diversity, making it a biologically relevant measure of the pools' carrying capacity. The significant effects of incoming detritus and incident light show that changes in local environments (e.g., the conversion of forest to cropping systems) strongly influence freshwater communities. Because changes in local environments do not affect detritivores and predators equally, one may expect functional shifts as sets of invertebrates with particular traits are replaced or complemented by other sets with different traits. © 2013 Springer Science+Business Media Dordrecht.  
  Address CNRS, EcoLab (UMR-CNRS 5245), 118 Route de Narbonne, 31062 Toulouse, France  
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  ISSN 00188158 (Issn) ISBN Medium  
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  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 517  
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Author (up) Diatta, Bétémondji Désiré ; Niass, Ousmane ; Diouf, Massamba ; Guéye, Mathieu ; Houel, Emeline ; Boetsch, Gilles doi  openurl
  Title Diversité et composition phytochimique des bâtonnets frotte-dents (cure-dents) proposés chez les Peul de la commune de Tessékéré (Ferlo Nord, Sénégal) Type Journal Article
  Year 2021 Publication Journal of Applied Biosciences Abbreviated Journal  
  Volume 158 Issue Pages 16267-16281  
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  Abstract Objectifs : Le but de cette étude était de déterminer la composition phytochimique et la teneur en grandes classes chimiques des tiges les plus utilisées comme bâtonnets frotte-dents chez les peul de Widou Thiengoli au Nord Ferlo (Sénégal). Méthodes et résultats : Des entretiens ouverts semi structurés ont permis de recueillir les plantes les plus utilisées. L’indice de fidélité renseigne sur la convergence des usages quant à l’emploi des plantes comme bâtonnets frotte-dent comparé aux autres pratiques cosmétiques. L’étude de la composition phytochimique des tiges a ciblé 8 classes chimiques. Les tanins et les saponines sont très fréquents ; les terpénoïdes et les leuco-anthocyanines presque inexistants. Un dosage des flavonoïdes, alcaloïdes et polyphénols, réalisé chez des extraits aqueux, a porté sur 12 plantes. Les meilleures teneurs en polyphénols et alcaloïdes sont recueillies chez Anogeissus leiocarpa, et la meilleure en flavonoïdes chez Commiphora africana. Conclusion et applicabilité des résultats : Ces résultats permettent de sélectionner à travers la composition phytochimique des plantes, les espèces présentant de potentielles activités antimicrobiennes, car renfermant des composés phytochimique doués de fonctions germicides, au- delà de la fonction mécanique connue des bâtonnets dans l’élimination de la plaque dentaire.  
  Address  
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  Publisher Elewa Place of Publication Editor  
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  ISSN 1997-5902 ISBN Medium  
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  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 1053  
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Author (up) Djenontin Tindo, S.; Amusant, N.; Dangou, J.; Wotto, D.V.; Avlessi, F.; Dahouénon-Ahoussi, E.; Lozano, P.; Pioch, D.; Sohounhloué, K.C.D. pdf  openurl
  Title Screening of Repellent, Termiticidal and Preventive activities on Wood, of Azadirachta indica and Carapa procera (Meliaceae) seeds oils Type Journal Article
  Year 2012 Publication International Research Journal of Biological Sciences Abbreviated Journal ISCA J. Biological Sci.  
  Volume 1 Issue 3 Pages 25-29  
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  Publisher International Science Congress Association Place of Publication Editor  
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  Call Number EcoFoG @ webmaster @ Serial 462  
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Author (up) Dlouhá, J.; Alméras, T.; Beauchene, J.; Clair, B.; Fournier, M. url  doi
openurl 
  Title Biophysical dependences among functional wood traits Type Journal Article
  Year 2018 Publication Functional Ecology Abbreviated Journal Funct Ecol  
  Volume 32 Issue 12 Pages 2652-2665  
  Keywords basic density; biomechanical traits; hydraulic traits; wood traits  
  Abstract Abstract Wood properties and especially wood density have been used as functional traits organized along major axes of species life history and strategy. Beyond statistical analyses, a better mechanistic understanding of relationships among wood traits is essential for ecologically relevant interpretation of wood trait variations. A set of theoretical relationships mechanistically linking wood basic density with some other wood traits is derived from cellular material physics. These theoretical models picture basic physical constraints and thus provide null hypotheses for further ecological studies. Analysis is applied to data from two original datasets and several datasets extracted from the literature. Results emphasize the strong physical constraint behind the link between basic density and maximal storable water on the one hand, and elastic modulus on the other hand. Beyond these basic physical constraints, the developed framework reveals physically less expected trends: the amount of free water available for physiological needs increases in less dense wood of fast-growing species, and the cell wall stiffness decreases with density in temperate hardwoods and is higher in sapling stages in the rainforest understorey where competition for light is associated with high mechanical risk. We emphasize the use of theoretically independent traits derived from models of cellular material physics to investigate the functional variation of wood traits together with their environmental and phylogenetic variations. Although the current study is limited to basic density, green wood lumen saturation and wood specific modulus, we further emphasize the identification of complementary independent wood traits representing other biomechanical functions, nutrient storage, hydraulic conductance and resistance to drought. A plain language summary is available for this article.  
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  Publisher John Wiley & Sons, Ltd (10.1111) Place of Publication Editor  
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  ISSN 0269-8463 ISBN Medium  
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  Notes doi: 10.1111/1365-2435.13209 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 851  
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Author (up) Do, N.A.; Dias, D.; Zhang, Z.; Huang, X.; Nguyen, T.T.; Pham, V.V.; Nait-Rabah, O. url  doi
openurl 
  Title Study on the behavior of squared and sub-rectangular tunnels using the Hyperstatic Reaction Method Type Journal Article
  Year 2020 Publication Transportation Geotechnics Abbreviated Journal Transp. Geotech.  
  Volume 22 Issue 100321 Pages  
  Keywords Finite element method; Lining; Squared shape; Sub-rectangular shape; Tunnel; efficiency measurement; finite element method; numerical model; transportation development; transportation planning; tunnel design; tunnel lining  
  Abstract  
  Address Saint-Petersburg Mining University, Russian Federation  
  Corporate Author Thesis  
  Publisher Elsevier Ltd Place of Publication Editor  
  Language Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 22143912 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 915  
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Author (up) Donald, J.; Maxfield, P.; Leroy, C.; Ellwood, M.D.F. doi  openurl
  Title Epiphytic suspended soils from Borneo and Amazonia differ in their microbial community composition Type Journal Article
  Year 2020 Publication Acta Oecologica Abbreviated Journal Acta Oecol.  
  Volume 106 Issue Pages  
  Keywords Asplenium; Bacteria; Borneo; Bromeliaceae; Canopy; French Guiana; Fungi; Plfa; Rainforest; bacterium; community composition; epiphyte; fungus; microbial community; niche; relative abundance; soil microorganism; species diversity; tropical forest; Amazonia; Borneo; Danum Valley; East Malaysia; French Guiana; Malaysia; Nouragues; Sabah; Asplenium; Asplenium nidus; Aves; Bacteria (microorganisms); Bromeliaceae; Fungi  
  Abstract Microbial organisms support the high species diversity associated with tropical forests, and likely drive functional processes, but microorganisms found in rainforest canopies are not well understood. We quantified the microbial diversity of suspended soils from two classical epiphytic model systems (bromeliads & bird's nest ferns) across two localities: the Nouragues Reserve in French Guiana and Danum Valley in Malaysian Borneo. Non-epiphytic suspended soils were also collected as controls at the Nouragues Reserve. Effects of epiphyte type and sample location on microbial community composition were determined using Phospholipid Fatty Acid (PLFA) analysis. Total microbial biomass remained constant across the suspended soil types, but PLFA peaks denoting the relative abundance of different microbes varied between bromeliads, bird's nest ferns and non-epiphytic control soils. Suspended soils associated with bird's nest ferns from Borneo contained a microbial community significantly different in composition from those of congeneric bird's nest ferns from Amazonia, due to shifts in the relative abundance of fungi and bacteria. Our findings reveal that epiphytes create convergent niches for microorganisms in tropical canopies, while highlighting the sensitive nature of suspended soil microbial communities. © 2020 Elsevier Masson SAS  
  Address 20 Baily Place, Cheswick, Bristol, BS16 1BG, United Kingdom  
  Corporate Author Thesis  
  Publisher Elsevier B.V. Place of Publication Editor  
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  ISSN 1146609x (Issn) ISBN Medium  
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  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 959  
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Author (up) Donald, Julian ; Murienne, Jérôme ; Chave, Jérome ; Iribar, Amaia ; Louisanna, Eliane ; Manzi, Sophie ; Roy, Melanie ; Tao, Shengli ; Orivel, Jérome ; Schimann, Heidy; Zinger, Lucie doi  openurl
  Title Multi-taxa environmental DNA inventories reveal distinct taxonomic and functional diversity in urban tropical forest fragments Type Journal Article
  Year 2021 Publication Global Ecology and Conservation Abbreviated Journal  
  Volume Issue 29 Pages e01724  
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  Abstract Urban expansion and associated habitat transformation drives shifts in biodiversity, with declines in taxonomic and functional diversity. Forests fragments within urban landscapes offer a number of ecosystem services, and help to maintain biodiversity and ecosystem functions. Here, we focus on a tropical forest environment, and on the soil biota. Using eDNA metabarcoding, we compare forest fragments within the city of Cayenne, French Guiana, with a neighbouring continuous undisturbed forest. We wished to determine if urban forest fragments conserve high levels of alpha and beta diversity as well as similar functional composition for plants, soil animals, fungi and bacteria. We found that alpha diversity is similar across habitats for plants and fungi, lower in urban forests for metazoans and higher for bacteria. We also found that urban forests communities differ from undisturbed forests in their taxonomic composition, with urban forests exhibiting greater turnover between fragments potentially caused by ecological drift and limited dispersal. However, their functional composition exhibited limited differences, with an enrichment of palms, arbuscular mycorrhizal fungi and bacteria and a depletion of climber plants and termites. Thus, although urban forest fragments do shelter soil biodiversity that differs from native forests, the losses of soil functions may be relatively limited. This study demonstrates the strong potential of a multi-taxa eDNA approach for rapid inventories across taxonomic kingdoms, in particular for cryptic soil diversity. It also demonstrates the key role of urban forest fragments in conserving biodiversity and ecosystem function, and points to a need for more systematic monitoring of these areas in urban management plans.  
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  Call Number EcoFoG @ webmaster @ Serial 1025  
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