Author: "Jean-François Carrias" / Topic: biology - Searchworks@Jio Institute Digital Library Search Results

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1. In situ resistance, not immigration, supports invertebrate community resilience to drought intensification in a Neotropical ecosystem

Author: Joséphine Leflaive, Nicholas A. C. Marino, Vinicius F. Farjalla, Thibaut Rota, Diane S. Srivastava, Bruno Corbara, Régis Céréghino, Vincent E. J. Jassey, Céline Leroy, Jean-François Carrias, Arthur Compin, Camille Bonhomme, Universidade Federal do Estado do Rio de Janeiro (UNIRIO), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Laboratoire Microorganismes : Génome et Environnement (LMGE), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), University of British Columbia (UBC), Ecologie des forêts de Guyane (UMR ECOFOG), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-AgroParisTech-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), EC2CO‐Biohefect, ANR-18-CE02-0015,RESILIENCE,Démêler les rôles des traits biologiques et de la dynamique des métacommunautés sur la résilience multifonctionnelle des écosystèmes néotropicaux(2018), ANR-10-LABX-0025,CEBA,CEnter of the study of Biodiversity in Amazonia(2010), Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), and Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, Metacommunity, media_common.quotation_subject, Resistance, Climate change, Community, Biology, [SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics, Phylogenetics and taxonomy, 010603 evolutionary biology, 01 natural sciences, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Animals, Ecosystem, Freshwater ecosystems Functional traits, Ecology, Evolution, Behavior and Systematics, media_common, Community resilience, Drought, Resilience, Resistance (ecology), Ecology, 010604 marine biology & hydrobiology, fungi, Community structure, food and beverages, Emigration and Immigration, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, 15. Life on land, Invertebrates, Droughts, 13. Climate action, Biological dispersal, Animal Science and Zoology, Psychological resilience, [SDE.BE]Environmental Sciences/Biodiversity and Ecology
Abstract: International audience; While future climate scenarios predict declines in precipitations in many regions of the world, little is known of the mechanisms underlying community resilience to prolonged dry seasons, especially in ‘naïve’ Neotropical rainforests. Predictions of community resilience to intensifying drought are complicated by the fact that the underlying mechanisms are mediated by species' tolerance and resistance traits, as well as rescue through dispersal from source patches.We examined the contribution of in situ tolerance‐resistance and immigration to community resilience, following drought events that ranged from the ambient norm to IPCC scenarios and extreme events. We used rainshelters above rainwater‐filled bromeliads of French Guiana to emulate a gradient of drought intensity (from 1 to 3.6 times the current number of consecutive days without rainfall), and we analysed the post‐drought dynamics of the taxonomic and functional community structure of aquatic invertebrates to these treatments when immigration is excluded (by netting bromeliads) or permitted (no nets). Drought intensity negatively affected invertebrate community resistance, but had a positive influence on community recovery during the post‐drought phase. After droughts of 1 to 1.4 times the current intensities, the overall invertebrate abundance recovered within invertebrate life cycle durations (up to 2 months). Shifts in taxonomic composition were more important after longer droughts, but overall, community composition showed recovery towards baseline states. The non‐random patterns of changes in functional community structure indicated that deterministic processes like environmental filtering of traits drive community re‐assembly patterns after a drought event. Community resilience mostly relied on in situ tolerance‐resistance traits. A rescue effect of immigration after a drought event was weak and mostly apparent under extreme droughts.Under climate change scenarios of drought intensification in Neotropical regions, community and ecosystem resilience could primarily depend on the persistence of suitable habitats and on the resistance traits of species, while metacommunity dynamics could make a minor contribution to ecosystem recovery. Climate change adaptation should thus aim at identifying and preserving local conditions that foster in situ resistance and the buffering effects of habitat features.
Published: 2020
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2. Ecological determinants of community structure across the trophic levels of freshwater food webs: a test using bromeliad phytotelmata

Author: Régis Céréghino, Bruno Corbara, Jean-François Carrias, Céline Leroy, Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Fondation pour la Recherche sur la Biodiversité (FRB Project MICBROME, AAP-IN-2009-038), ANR-10-LABX-0025,CEBA,CEnter of the study of Biodiversity in Amazonia(2010), Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire Microorganismes : Génome et Environnement - Clermont Auvergne (LMGE), Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), ANR: 10-LABX-0025,CEBA,CEnter of the study of Biodiversity in Amazonia(2010), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])
Subjects: 0106 biological sciences, Aquatic Science, Biology, [SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics, Phylogenetics and taxonomy, 010603 evolutionary biology, 01 natural sciences, Predation, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Abundance (ecology), Niche, 14. Life underwater, Functional group (ecology), Trophic level, Abiotic component, Ecology, 010604 marine biology & hydrobiology, Community structure, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, 15. Life on land, Neotropical, Food web, Tank bromeliad, French Guiana, Habitat, REGION NEOTROPICALE, Functional group, Trophic interactions, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Environmental filtering
Abstract: International audience; Understanding the relative importance of habitat and biotic drivers on community assembly across food web components is an important step towards predicting the consequences of environmental changes. Because documenting entire food webs is often impractical, this question has been only partially investigated. Here, we partitioned variation in species assemblages of the major components of tank bromeliad food webs (bacteria, algae, protozoans, detritivorous and predatory invertebrates) into habitat and biotic determinants and examined the influence of habitat variables and predator or prey abundance on all taxonomic assemblages. Ecological determinism of assemblage structure ranged from weak in bacteria (
Published: 2019
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3. Assemblages of anoxygenic phototrophic bacteria in tank bromeliads exhibit a host‐specific signature

Author: Anne‐hélène Le Jeune, Régis Céréghino, Christian Jeanthon, François Enault, Corinne Bardot, Anne-Catherine Lehours, Vincent Darbot, Antoine Vergne, Jean-François Carrias, Eric Giraud, Bruno Corbara, Isabelle Mary, Céline Leroy, Laboratoire Microorganismes : Génome et Environnement (LMGE), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Ecologie des forêts de Guyane (UMR ECOFOG), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-AgroParisTech-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Adaptation et diversité en milieu marin (AD2M), Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des symbioses tropicales et méditerranéennes (UMR LSTM), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Université de Montpellier (UM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Université de Montpellier (UM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro - Montpellier SupAgro, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), ANR-10-LABX-0025,CEBA,CEnter of the study of Biodiversity in Amazonia(2010), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université de Montpellier (UM)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)
Subjects: Assembly rules, [SDV]Life Sciences [q-bio], Plant Science, 03 medical and health sciences, Nitrogen fixation, Dominance (ecology), Plant–bacteria interactions, Ecology, Evolution, Behavior and Systematics, Phylogenetic analyses, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 0303 health sciences, Ecology, biology, Phototroph, 030306 microbiology, Illumina sequencing, 15. Life on land, biology.organism_classification, Anoxygenic photosynthesis, Rhodobacterales, Burkholderiales, [SDE]Environmental Sciences, Biological dispersal, Evolutionary ecology
Abstract: International audience; Anoxygenic phototrophic bacteria (APB) are a very significant metabolic functional group in the phytotelmata of tank-forming Bromeliaceae plants. Considering the close relationships existing between the bromeliad and its tank microbiota, the dominance of APB raises the question of their role in the ecology and evolution of these plants. Here, using pufM gene sequencing for taxonomic profiling, we investigated the structure of APB communities in the tanks of five bromeliad species exhibiting different habitat characteristics (i.e. physicochemical factors associated with the host), and occurring in different localities of French Guiana. We found that APB assemblages were specific to plant species and were less dependent on location or on bromeliad habitat characteristics. This convergence suggests that the identity of the bromeliad species per se is more important than habitat filtering or dispersal to control specific assembly rules for APB. The pufM OTUs were affiliated with five orders of Alpha- and Beta-proteobacteria (Rhodobacterales, Sphingomonadales, Rhizobiales, Burkholderiales and Rhodospirillales), and we assume that they may be major components of the core microbiota of plant-held waters. Our findings also revealed that up to 79% of the sequences were affiliated with APB clades possessing nitrogen-fixing genes suggesting that this metabolic capability is widespread within the APB community inhabiting tank bromeliads. We hypothesized that bromeliads may benefit nutritionally from associations with free-living APB capable to fix atmospheric nitrogen. Synthesis. Understanding the dominance of APB in tank bromeliads and determining whether a potential interplay exists between these partners is an intriguing aspect of possible mutualistic and coevolving interactions between the two existing forms of chlorophototrophy (i.e. bacteriochlorophyll-based anoxygenic and chlorophyll-based oxygenic phototrophy). In the present study, we found that bromeliad species was the main factor that explained variance in APB community composition. These findings suggest that APB and tank bromeliads may have a close, mutualistic relationship and we hypothesize according to our genomic analyses that APB may promote the bromeliad growth by provisioning essential nutrients like nitrogen.
Published: 2021
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4. Author response for 'Assemblages of anoxygenic phototrophic bacteria in tank bromeliads exhibit a host‐specific signature'

Author: Jean-François Carrias, Anne-Hélène Le Jeune, Régis Céréghino, Eric Giraud, Corinne Bardot, Christian Jeanthon, François Enault, Bruno Corbara, Céline Leroy, Isabelle Mary, Vincent Darbot, Anne-Catherine Lehours, and Antoine Vergne
Subjects: Phototroph, biology, Ecology, biology.organism_classification, Signature (topology), Anoxygenic photosynthesis, Host specific, Bacteria
Published: 2021
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5. Resource availability drives bacterial succession during leaf-litter decomposition in a bromeliad ecosystem

Author: Céline Leroy, Guillaume Borrel, Mélanie Gerphagnon, Jean-François Carrias, Héctor Rodríguez-Pérez, Camille Loiseau, Isabelle Mary, Bruno Corbara, Régis Céréghino, Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Ecologie des forêts de Guyane (UMR ECOFOG), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-AgroParisTech-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Biologie Evolutive de la Cellule Microbienne - Evolutionary Biology of the Microbial Cell, Institut Pasteur [Paris], Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), This work was supported by the Agence Nationale de la Recherche throughout the Rainwebs project (grant number ANR-12-BSV7- 0022–01) and an ‘Investissement d'Avenir’ (Labex CEBA, grant number ANR- 10-LABX-25–01)., ANR-10-LABX-0025,CEBA,CEnter of the study of Biodiversity in Amazonia(2010), ANR-12-BSV7-0022,RAINWEBS,Que se passera-t-il si les forêts tropicales s'assèchent ? Changement climatique et réseaux trophiques le long d'un gradient latitudinal(2012), Institut Pasteur [Paris] (IP), Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), and Université de Toulouse (UT)
Subjects: 0106 biological sciences, Niche, Ecological succession, ecological succession, Biology, Environment, [SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics, Phylogenetics and taxonomy, 010603 evolutionary biology, 01 natural sciences, Applied Microbiology and Biotechnology, Microbiology, 03 medical and health sciences, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Ecosystem, Community ecology, Primary succession, 030304 developmental biology, Amplicon sequencing, 0303 health sciences, Decomposition, decomposition, Ecology, Community, Bacteria, amplicon sequencing, Community structure, bacterial diversity, 15. Life on land, Plant litter, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, Plant Leaves, Bacterial diversity, 16S rRNA gene, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Microcosm, community ecology
Abstract: Despite the growing number of investigations on microbial succession during the last decade, most of our knowledge on primary succession of bacteria in natural environments comes from conceptual models and/or studies of chronosequences. Successional patterns of litter-degrading bacteria remain poorly documented, especially in undisturbed environments. Here we conducted an experiment with tank bromeliads as natural freshwater microcosms to assess major trends in bacterial succession on two leaf-litter species incubated with or without animal exclusion. We used amplicon sequencing and a co-occurrence network to assess changes in bacterial community structure according to treatments. Alpha-diversity and community complexity displayed the same trends regardless of the treatments, highlighting that primary succession of detrital-bacteria is subject to resource limitation and biological interactions, much like macro-organisms. Shifts in bacterial assemblages along the succession were characterized by an increase in uncharacterized taxa and potential N-fixing bacteria, the latter being involved in positive co-occurrence between taxa. These findings support the hypothesis of interdependence between taxa as a significant niche-based process shaping bacterial communities during the advanced stage of succession.
Published: 2020
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6. Ecological response to altered rainfall differs across the Neotropics

Author: Dimaris Acosta Mercado, Régis Céréghino, Sarah L. Amundrud, Ignacio M. Barberis, Bruno Corbara, Edd Hammill, Alice B. A. Campos, Céline Leroy, Emilio Realpe, Paula M. de Omena, Nicholas A. C. Marino, Trisha B. Atwood, Olivier Dézerald, Gustavo Q. Romero, Jean-François Carrias, M. Kurtis Trzcinski, Vinicius F. Farjalla, Guillermo Montero, Fabiola Ospina-Bautista, Rodrigo Freire, Gustavo C. O. Piccoli, A. Andrew M. MacDonald, Pablo A. P. Antiqueira, Juliana S. Leal, Diane S. Srivastava, University of British Columbia (UBC), Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Universidade Federal do Rio de Janeiro (UFRJ), University of Puerto Rico at Mayagüez (UPR-M), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Ecologie des forêts de Guyane (UMR ECOFOG), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-AgroParisTech-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Universidade Estadual de Campinas (UNICAMP), Instituto de Investigaciones en Ciencias Agrarias de Rosario [Zavalla] (IICAR), Consejo Nacional de Investigaciones Científicas y Técnicas [Buenos Aires] (CONICET)-Facultad de Ciencias Agrarias [Zavalla] (FCAGR), Universidad Nacional de Rosario [Santa Fe]-Universidad Nacional de Rosario [Santa Fe], Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Terre et Environnement de Lorraine (OTELo), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Écologie et santé des écosystèmes (ESE), AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Utah State University (USU), Universidade Estadual Paulista Júlio de Mesquita Filho = São Paulo State University (UNESP), Universidad de los Andes [Bogota] (UNIANDES), Universidad de Caldas [Manizales, Colombia], ANR-10-LABX-0025,CEBA,CEnter of the study of Biodiversity in Amazonia(2010), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire Microorganismes : Génome et Environnement - Clermont Auvergne (LMGE), Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS), Université des Antilles (UA)-Centre National de la Recherche Scientifique (CNRS)-Université de Guyane (UG)-AgroParisTech-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), ANR-10-LABX-25-01/10-LABX-0025,CEBA,CEnter of the study of Biodiversity in Amazonia(2010), University of British Columbia, Université de Toulouse, University of Puerto Rico Mayaguez Campus, Université Montpellier, Université des Antilles), Université Clermont-Auvergne, Universidad Nacional de Rosario, Université de Lorraine, Ecology and Ecosystem Health, Utah State University, Universidade Estadual Paulista (Unesp), Andes University, Universidad de Caldas, Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Universidade Estadual de Campinas = University of Campinas (UNICAMP), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-INSTITUT AGRO Agrocampus Ouest, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), and Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, Climate Change, Rain, macroinvertebrates, Climate change, Precipitation, Biology, contingency, precipitation, [SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics, Phylogenetics and taxonomy, 010603 evolutionary biology, 01 natural sciences, Contingency, Hydrology (agriculture), Freshwater, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Distributed experiment, Animals, Ecosystem, freshwater, Ecology, Evolution, Behavior and Systematics, Invertebrate, Biomass (ecology), Phytotelmata, Macroinvertebrates, Ecology, 010604 marine biology & hydrobiology, Aquatic ecosystem, Tropics, Global change biology, global change biology, 15. Life on land, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, Invertebrates, distributed experiment, Droughts, Habitat, 13. Climate action, phytotelmata, [SDE.BE]Environmental Sciences/Biodiversity and Ecology
Abstract: Made available in DSpace on 2020-12-12T01:58:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-04-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Consejo Nacional de Investigaciones Científicas y Técnicas Natural Sciences and Engineering Research Council of Canada University of British Columbia Universidad de los Andes Labex Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Universidad Nacional de Rosario Facultad de Ciencias, Universidad de los Andes Agence Nationale de la Recherche Agencia Nacional de Promoción Científica y Tecnológica Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) There is growing recognition that ecosystems may be more impacted by infrequent extreme climatic events than by changes in mean climatic conditions. This has led to calls for experiments that explore the sensitivity of ecosystems over broad ranges of climatic parameter space. However, because such response surface experiments have so far been limited in geographic and biological scope, it is not clear if differences between studies reflect geographic location or the ecosystem component considered. In this study, we manipulated rainfall entering tank bromeliads in seven sites across the Neotropics, and characterized the response of the aquatic ecosystem in terms of invertebrate functional composition, biological stocks (total invertebrate biomass, bacterial density) and ecosystem fluxes (decomposition, carbon, nitrogen). Of these response types, invertebrate functional composition was the most sensitive, even though, in some sites, the species pool had a high proportion of drought-tolerant families. Total invertebrate biomass was universally insensitive to rainfall change because of statistical averaging of divergent responses between functional groups. The response of invertebrate functional composition to rain differed between geographical locations because (1) the effect of rainfall on bromeliad hydrology differed between sites, and invertebrates directly experience hydrology not rainfall and (2) the taxonomic composition of some functional groups differed between sites, and families differed in their response to bromeliad hydrology. These findings suggest that it will be difficult to establish thresholds of “safe ecosystem functioning” when ecosystem components differ in their sensitivity to climatic variables, and such thresholds may not be broadly applicable over geographic space. In particular, ecological forecast horizons for climate change may be spatially restricted in systems where habitat properties mediate climatic impacts, and those, like the tropics, with high spatial turnover in species composition. Departmetn of Zoology and Biodiversity Research Centre University of British Columbia Ecolab Laboratoire Ecologie Fonctionnelle et Environnement CNRS UPS INPT Université de Toulouse Departamento de Ecologia Instituto de Biologia Centro de Ciências da Saúde Universidade Federal do Rio de Janeiro, Ilha do Fundão Programa de Pós-Graduação em Ecologia Universidade Federal do Rio de Janeiro, Ilha do Fundão Department of Biology University of Puerto Rico Mayaguez Campus AMAP IRD CIRAD CNRS INRA Université Montpellier, CEDEX-5 ECOFOG (AgroParisTech CIRAD CNRS INRA Université de Guyane Université des Antilles) CNRS LMGE (Laboratoire Microorganismes: Génome et Environnement) Université Clermont-Auvergne Laboratory of Multitrophic Interactions and Biodiversity Department of Animal Biology Institute of Biology University of Campinas (UNICAMP) Facultad de Ciencias Agrarias Instituto de Investigaciones en Ciencias Agrarias de Rosario IICAR-CONICET-UNR Universidad Nacional de Rosario Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC)-CNRS UMR 7360 Université de Lorraine, Campus Bridoux INRA Agrocampus-Ouest Ecology and Ecosystem Health, 65 rue de Saint-Brieuc Department of Watershed Sciences and the Ecology Center Utah State University Department of Forest and Conservation Sciences University of British Columbia Department of Zoology and Botany University of São Paulo State (UNESP/IBILCE) Department of Biological Sciences Andes University Departamento de Ciencias Biológicas Universidad de Caldas Department of Zoology and Botany University of São Paulo State (UNESP/IBILCE) FAPESP: # 2016/01209-9 Universidad Nacional de Rosario: 01209-9 Universidad Nacional de Rosario: 04603-4 Universidad Nacional de Rosario: 0877 Universidad Nacional de Rosario: 2012 Facultad de Ciencias, Universidad de los Andes: 2012-1 Universidad Nacional de Rosario: 2012-1 FAPESP: 2012/51143-3 Universidad Nacional de Rosario: 2014 Universidad Nacional de Rosario: 2014-9 FAPESP: 2014/04603-4 Universidad Nacional de Rosario: 2016 Universidad Nacional de Rosario: 400454 Universidad Nacional de Rosario: 51143-3 Agence Nationale de la Recherche: ANR-10-LABX-25-01 Agence Nationale de la Recherche: ANR-12-BSV7-0022-01 Agencia Nacional de Promoción Científica y Tecnológica: PICT-2010-1614 CAPES: PNPD-CAPES 2013/0877 PNPD-CAPES 2014/04603-4
Published: 2020
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7. Unexpectedly high bacteriochlorophyllaconcentrations in neotropical tank bromeliads

Author: Régis Céréghino, Benoit Kéraval, Bruno Corbara, Christian Jeanthon, Fanny Perrière, Jean-Pierre Aguer, Anne-Catherine Lehours, Céline Leroy, Anne-Hélène Le Jeune, and Jean-François Carrias
Subjects: 0301 basic medicine, Chlorophyll a, Phototroph, 030106 microbiology, Rainforest, 15. Life on land, Biology, biology.organism_classification, Agricultural and Biological Sciences (miscellaneous), Anoxygenic photosynthesis, Purple bacteria, 03 medical and health sciences, chemistry.chemical_compound, 030104 developmental biology, chemistry, 13. Climate action, Botany, Ecosystem, Bacteriochlorophyll A, Ecology, Evolution, Behavior and Systematics
Abstract: The contribution of bacteriochlorophyll a (BChl a) to photosynthetically driven electron transport is generally low in aquatic and terrestrial systems. Here, we provide evidence that anoxygenic bacterial phototrophy is widespread and substantial in water retained by tank bromeliads of a primary rainforest in French Guiana. An analysis of the water extracted from 104 randomly selected tank bromeliads using infrared fluorimetry suggested the overall presence of abundant anoxygenic phototrophic bacterial populations. We found that purple bacteria dominated these populations responsible for unusually high BChl a/chlorophyll a ratios (>50%). Our data suggest that BChl a-based phototrophy in tank bromeliads can have significant effects on the ecology of tank-bromeliad ecosystems and on the carbon and energy fluxes in Neotropical forests.
Published: 2016
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8. Desiccation resistance traits predict freshwater invertebrate survival and community response to drought scenarios in a Neotropical ecosystem

Author: Régis Céréghino, Thibaut Rota, Joséphine Leflaive, Vincent E.J. Jassey, Léa Françoise, Bruno Corbara, Céline Leroy, Arthur Compin, Camille Bonhomme, Vinicius F. Farjalla, Jean-François Carrias, Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), HYDRECO, Universidade Federal do Rio de Janeiro (UFRJ), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), ANR-18-CE02-0015,RESILIENCE,Démêler les rôles des traits biologiques et de la dynamique des métacommunautés sur la résilience multifonctionnelle des écosystèmes néotropicaux(2018), ANR-10-LABX-0025,CEBA,CEnter of the study of Biodiversity in Amazonia(2010), Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), HYDRECO GUYANE FRA, Partenaires IRSTEA, and Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)
Subjects: 0106 biological sciences, Biodiversity, General Decision Sciences, 010501 environmental sciences, Biology, [SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics, Phylogenetics and taxonomy, 010603 evolutionary biology, 01 natural sciences, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Climate change, LT50, Ecosystem, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences, Trophic level, Rainforests, Biomass (ecology), Macroinvertebrates, Ecology, Resistance (ecology), Community structure, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, 15. Life on land, Habitat, 13. Climate action, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Desiccation, Functional traits
Abstract: The intensification of dry seasons is a major threat to freshwater biodiversity in Neotropical regions. Little is known about resistance to drying stress and the underpinning traits in Neotropical freshwater species, so we don’t know whether desiccation resistance allows to anticipate shifts in biological diversity under future climate scenarios. Here, we used the aquatic invertebrates that live in the rainwater-filled leaves of tank bromeliads, to examine the extent to which desiccation resistance of species measured in the laboratory predicts community response to drought intensification in nature. We measured desiccation resistance in 17 invertebrate species (>90% of the biomass usually found in bromeliads of French Guiana) by recording the median lethal time (LT50) of experimental populations exposed to controlled conditions of residual moisture. In the field, we placed rainshelters above tank bromeliads to emulate drought scenarios ranging from the ambient norm to IPCC scenarios and extreme events, and we recorded the response of functional community structure. LT50 ranged from 4.18 to 19.06 days, and was related to cuticle content and dry body mass. Among other functional indicators that represent strategies to optimize resource use under stressful conditions (e.g., habitat use, trophic specialization), LT50 was the best predictor of community structure responses along a gradient of emulated drought intensities. Therefore, species’ LT50s measured under laboratory conditions can be used to forecast aquatic community response to drying stress in nature. Anticipating how species will cope with drought has never been more important for environmental managers to support climate change adaptation. We show that desiccation resistance in freshwater invertebrates is a key indicator of potential population size and local–global range shifts, and this could be especially true in the Neotropics where species have narrow physiological tolerances for climatic variation.
Published: 2020
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9. Functional traits and environmental conditions predict community isotopic niches and energy pathways across spatial scales

Author: Régis Céréghino, Olivier Dézerald, Angélica L. González, Nicholas A. C. Marino, Barbara A. Richardson, Michael J. Richardson, Gustavo C. O. Piccoli, Bruno Corbara, Vinicius F. Farjalla, Céline Leroy, Diane S. Srivastava, Gustavo Q. Romero, Jean-François Carrias, Ecologie des forêts de Guyane (UMR ECOFOG), Université des Antilles (UA)-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-AgroParisTech-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA), University of British Columbia (UBC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)-Université d'Auvergne - Clermont-Ferrand I (UdA), Université Blaise Pascal (Clermont Ferrand 2) (UBP), PRES Université de Clermont, Laboratoire Microorganismes : Génome et Environnement - Clermont Auvergne (LMGE), Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS), Universidade Federal do Rio de Janeiro [Rio de Janeiro] (UFRJ), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), ANR: 10-LABX-0025,CEBA,CEnter of the study of Biodiversity in Amazonia(2010), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-AgroParisTech-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université d'Auvergne - Clermont-Ferrand I (UdA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Terre et Environnement de Lorraine (OTELo), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT), Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Universidade Federal do Rio de Janeiro (UFRJ), Universidade Estadual Paulista Júlio de Mesquita Filho = São Paulo State University (UNESP), Institute for tropical ecosystem studies - ITES (San Juan, Puerto Rico), University of Puerto Rico (UPR), Universidade Estadual de Campinas = University of Campinas (UNICAMP), Rutgers University [Camden], Rutgers University System (Rutgers), ANR-10-LABX-0025,CEBA,CEnter of the study of Biodiversity in Amazonia(2010), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Terre et Environnement de Lorraine (OTELo), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD [France-Sud])
Subjects: 0106 biological sciences, Metacommunity, metacommunity, [SDV]Life Sciences [q-bio], Biology, 010603 evolutionary biology, 01 natural sciences, functional biogeography, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Ecology, Evolution, Behavior and Systematics, Trophic level, Apex predator, Ecological niche, Ecology, 010604 marine biology & hydrobiology, 15. Life on land, environmental heterogeneity, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, functional diversity, isotopic niche, Food web, Habitat, food webs, trophic structure, Spatial ecology, Species richness, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, energy pathways
Abstract: International audience; Despite ongoing research in food web ecology and functional biogeography, the links between food web structure, functional traits and environmental conditions across spatial scales remain poorly understood. Trophic niches, defined as the amount of energy and elemental space occupied by species and food webs, may help bridge this divide.Here, we ask how the functional traits of species, the environmental conditions of habitats and the spatial scale of analysis jointly determine the characteristics of trophic niches. We used isotopic niches as a proxy of trophic niches, and conducted analyses at spatial scales ranging from local food webs and metacommunities to geographically distant sites.We sampled aquatic macroinvertebrates from 104 tank bromeliads distributed across five sites from Central to South America and compiled the macroinvertebrates’ functional traits and stable isotope values (δ15N and δ13C). We assessed how isotopic niches within each bromeliad were influenced by the functional trait composition of their associated invertebrates and environmental conditions (i.e., habitat size, canopy cover [CC] and detrital concentration [DC]). We then evaluated whether the diet of dominant predators and, consequently, energy pathways within food webs reflected functional and environmental changes among bromeliads across sites. At last, we determined the extent to which the isotopic niches of macroinvertebrates within each bromeliad contributed to the metacommunity isotopic niches within each site and compared these metacommunity‐level niches over biogeographic scales. At the bromeliad level, isotopic niches increased with the functional richness of species in the food web and the DC in the bromeliad. The diet of top predators tracked shifts in prey biomass along gradients of CC and DC. Bromeliads that grew under heterogeneous CC displayed less trophic redundancy and therefore combined to form larger metacommunity isotopic niches. At last, the size of metacommunity niches depended on within‐site heterogeneity in CC.Our results suggest that the trophic niches occupied by food webs can predictably scale from local food webs to metacommunities to biogeographic regions. This scaling process is determined by both the functional traits of species and heterogeneity in environmental conditions.
Published: 2018
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10. What drives detrital decomposition in neotropical tank bromeliads?

Author: Céline Leroy, M. Kurtis Trzcinski, Bruno Corbara, Jean-François Carrias, Alain Dejean, Olivier Dézerald, Régis Céréghino, Laboratoire de Chimie des polymères organiques (LCPO), Université Sciences et Technologies - Bordeaux 1-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)-Université d'Auvergne - Clermont-Ferrand I (UdA), Ecologie des forêts de Guyane (UMR ECOFOG), Université des Antilles (UA)-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-AgroParisTech-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA), Laboratoire Microorganismes : Génome et Environnement - Clermont Auvergne (LMGE), Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS), Ecologie des forêts de Guyane (ECOFOG), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université des Antilles et de la Guyane (UAG)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université d'Auvergne - Clermont-Ferrand I (UdA)-Centre National de la Recherche Scientifique (CNRS), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-AgroParisTech-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Université Clermont Auvergne (UCA), Écologie et santé des écosystèmes (ESE), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, Evolution et Diversité Biologique (EDB), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD [France-Sud]), Université Clermont Auvergne [2017-2020] (UCA [2017-2020]), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Agence Nationale de la Recherche throught the Rainwebs project [ANR-12-BSV7-0022-01], 'Investissement d'Avenir' grant [CEBA: ANR-10-LABX-25-01], Centre National de la Recherche Scientifique, Fond Social Europeen., Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Université Sciences et Technologies - Bordeaux 1-Institut de Chimie du CNRS (INC), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020]), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), and Université de Toulouse (UT)
Subjects: 0106 biological sciences, Rainforest, Eperua, Aquatic Science, Biology, [SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics, Phylogenetics and taxonomy, 010603 evolutionary biology, 01 natural sciences, s Leaf litter, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Ecosystem, Context dependency, ComputingMilieux_MISCELLANEOUS, Biomass (ecology), Phytotelmata, Ecology, 010604 marine biology & hydrobiology, Detritivore, Food webs, Leaf litter, Food web, 15. Life on land, Plant litter, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, biology.organism_classification, Habitat, Litter, Ecosystem function, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, [SDV.EE.IEO]Life Sciences [q-bio]/Ecology, environment/Symbiosis
Abstract: International audience; 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.
Published: 2017
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11. Are ontogenetic shifts in foliar structure and resource acquisition spatially conditioned in tank-bromeliads?

Author: Frédéric Petitclerc, Bruno Corbara, Matthis Petit, Alain Dejean, Céline Leroy, Jean-François Carrias, Olivier Dézerald, and Régis Céréghino
Subjects: Phenotypic plasticity, δ13C, Plant morphology, Ontogeny, Botany, Biological dispersal, Context (language use), Plant Science, 15. Life on land, Adaptation, Biology, Ecology, Evolution, Behavior and Systematics, Trichome
Abstract: The phenotypic plasticity of plants has been explored as a function of either ontogeny (apparent plasticity) or environment (adaptive plasticity), although few studies have analyzed these factors together. In the present study, we take advantage of the dispersal of Aechmea mertensii bromeliads by Camponotus femoratus or Pachycondyla goeldii ants in shaded and sunny environments, respectively, to quantify ontogenetic changes in morphological, foliar, and functional traits, and to analyze ontogenetic and ant species effects on 14 traits. Most of the morphological (plant height, number of leaves), foliar (leaf thickness, leaf mass area, total water content, trichome density), and functional (leaf δ13C) traits differed as a function of ontogeny. Conversely, only leaf δ15N showed an adaptive phenotypic plasticity. On the other hand, plant width, tank width, longest leaf length, stomatal density, and leaf C concentration showed an adaptation to local environment with ontogeny. The exception was leaf N concentration, which showed no trend at all. Aechmea mertensii did not show an abrupt morphological modification such as in heteroblastic bromeliads, although it was characterized by strong, size-related functional modifications for CO2 acquisition. The adaptive phenotypic variation found between the two ant species indicates the spatially conditioned plasticity of A. mertensii in the context of insect-assisted dispersal. However, ant-mediated effects on phenotypic plasticity in A. mertensii are not obvious because ant species and light environment are confounding variables. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 175, 299–312.
Published: 2014
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12. The influence of light, substrate and seed origin on the germination and establishment of an ant-garden bromeliad

Author: Bruno Corbara, Céline Leroy, Jérôme Orivel, Alain Dejean, Frédéric Petitclerc, Jean-François Carrias, Régis Céréghino, Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Ecologie des forêts de Guyane (UMR ECOFOG), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-AgroParisTech-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Université de Clermond-Ferrand 2, Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Agence Nationale de la Recherche (CEBA) : ANR-10-LABX-0025, Laboratoire Microorganismes : Génome et Environnement - Clermont Auvergne (LMGE), Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD [France-Sud]), Université des Antilles (UA)-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-AgroParisTech-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020]), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), and Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Bromeliaceae, 0106 biological sciences, biomeliad, plant performance, Light, forêt tropicale humide, [SDV]Life Sciences [q-bio], plant, Plant Science, Biology, 010603 evolutionary biology, 01 natural sciences, survival, écologie tropicale, tropical rain forests, Nest, Botany, Relative growth rate, Animals, Aechmea mertensii, Symbiosis, Ecosystem, Ecology, Evolution, Behavior and Systematics, Plant evolution, Abiotic component, Behavior, Animal, Ants, fungi, Sowing, food and beverages, General Medicine, 15. Life on land, Biological Evolution, ANT, bromeliad, French Guiana, Plant Leaves, germination, Germination, Biological dispersal, guyane française, Gardens, performance, 010606 plant biology & botany, aechmea mertensii
Abstract: Plant germination and development depend upon a seed's successful dispersal into a suitable habitat and its ability to grow and survive within the surrounding biotic and abiotic environment. The seeds of Aechmea mertensii, a tank-bromeliad species, are dispersed by either Camponotus femoratus or Neoponera goeldii, two ant species that initiate ant gardens (AGs). These two mutualistic ant species influence the vegetative and reproductive traits of the bromeliad through their divergent ecological preferences (i.e. light and substrate). We hypothesised that the seeds dispersed by these two ant species have underlying genetic differences affecting germination, growth and survival of A. mertensii seedlings in different ways. To test this, we used an experimental approach consisting of sowing seeds of A. mertensii: (i) taken from the two AG-ant associations (i.e. seed origin), (ii) in two contrasting light conditions, and (iii) on three different substrates. Light and substrate had significant effects on germination, survival and on eight key leaf traits reflecting plant performance. Seed origin had a significant effect only on germination and on two leaf traits (total dry mass and relative growth rate). Overall, this bromeliad performs better (i.e. high growth and survival rates) when growing both in the shade and in the carton nest developed by C. femoratus ants. These results suggest that the plasticity of the tank bromeliad A. mertensii is mainly due to environment but also to genetic differences related to seed origin, as some traits are heritable. Thus, these two ant species may play contrasting roles in shaping plant evolution and speciation.
Published: 2017
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13. Understorey environments influence functional diversity in tank-bromeliad ecosystems

Author: Bruno Corbara, Olivier Brouard, Régis Céréghino, Alain Dejean, Céline Leroy, Laurent Pélozuelo, and Jean-François Carrias
Subjects: 0106 biological sciences, Biomass (ecology), Detritus, Range (biology), Ecology, 010604 marine biology & hydrobiology, Understory, Aquatic Science, Biology, 010603 evolutionary biology, 01 natural sciences, Food web, Botany, Litter, Ecosystem, Invertebrate
Abstract: 1. A substantial fraction of the freshwater available in neotropical forests is impounded within the rosettes of bromeliads that form aquatic islands in a terrestrial matrix. The ecosystem functioning of bromeliads is known to be influenced by the composition of the contained community but it is not clear whether bromeliad food webs remain functionally similar against a background of variation in the understorey environment. 2. We considered a broad range of environmental conditions, including incident light and incoming litter, and quantified the distribution of a very wide range of freshwater organisms (from viruses to macroinvertebrates) to determine the factors that influence the functional structure of bromeliad food webs in samples taken from 171 tank-bromeliads. 3. We observed a gradient of detritus-based to algal-based food webs from the understorey to the overstorey. Algae, rotifers and collector and predatory invertebrates dominated bromeliad food webs in exposed areas, whereas filter-feeding insects had their highest densities in shaded forest areas. Viruses, bacteria and fungi showed no clear density patterns. Detritus decomposition is mainly due to microbial activity in understorey bromeliads where filter feeders are the main consumers of microbial and particulate organic matter (POM). Algal biomass may exceed bacterial biomass in sun-exposed bromeliads where amounts of detritus were lower but functional diversity was highest. 4. Our results provide evidence that tank-bromeliads, which grow in a broad range of ecological conditions, promote aquatic food web diversity in neotropical forests. Moreover, although bromeliad ecosystems have been categorised as detritus-based systems in the literature, we show that algal production can support a non-detrital food web in these systems.
Published: 2012
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14. Ant-plant mutualisms promote functional diversity in phytotelm communities

Author: Céline Leroy, Caroline Ségura, Jean-François Carrias, Christopher Bosc, Alain Dejean, Régis Céréghino, Bruno Corbara, and Laurent Pélozuelo
Subjects: 0106 biological sciences, Ecology, 010604 marine biology & hydrobiology, media_common.quotation_subject, Community structure, Biodiversity, Interspecific competition, 15. Life on land, Biology, 010603 evolutionary biology, 01 natural sciences, Competition (biology), Myrmecophyte, Abundance (ecology), Ecosystem, Epiphyte, Ecology, Evolution, Behavior and Systematics, media_common
Abstract: Our understanding of the contribution of interspecific interactions to functional diversity in nature lags behind our knowledge of spatial and temporal patterns. Although two-species mutualisms are found in all types of ecosystems, the study of their ecological influences on other community members has mostly been limited to third species, while their influence on entire communities remains largely unexplored. 2. We hypothesized that mutualistic interactions between two respective ant species and an epiphyte mediate the biological traits composition of entire invertebrate communities that use the same host plant, thereby affecting food webs and functional diversity at the community level. 3. Aechmea mertensii (Bromeliaceae) is both a phytotelm ('plant-held water') and an ant-garden epiphyte. We sampled 111 bromeliads (111 aquatic invertebrate communities) associated with either the ant Pachycondyla goeldii or Camponotus femoratus. The relationships between ants, bromeliads and invertebrate abundance data were examined using a redundancy analysis. Biological traits information for invertebrates was structured using a fuzzy-coding technique, and a co-inertia analysis between traits and abundance data was used to interpret functional differences in bromeliad ecosystems. 4. The vegetative traits of A. mertensii depended on seed dispersion by C. femoratus and P. goeldii along a gradient of local conditions. The ant partner selected sets of invertebrates with traits that were best adapted to the bromeliads' morphology, and so the composition of the biological traits of invertebrate phytotelm communities depends on the identity of the ant partner. Biological traits suggest a bottom-up control of community structure in C. femoratus-associated phytotelmata and a greater structuring role for predatory invertebrates in P. goeldii-associated plants. 5. This study presents new information showing that two-species mutualisms affect the functional diversity of a much wider range of organisms. Most biological systems form complex networks where nodes (e. g. species) are more or less closely linked to each other, either directly or indirectly, through intermediate nodes. Our observations provide community-level information about biological interactions and functional diversity, and perspectives for further observations intended to examine whether large-scale changes in interacting species/community structure over broad geographical and anthropogenic gradients affect ecosystem functions.
Published: 2011
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15. High and differential viral infection rates within bacterial ‘morphopopulations’ in a shallow sand pit lake (Lac de Créteil, France)

Author: Bashir Arnous, Télesphore Sime-Ngando, A. S. Pradeep Ram, Jean-François Carrias, Michael Danger, and Gérard Lacroix
Subjects: 0106 biological sciences, 0303 health sciences, Ecology, 030306 microbiology, 010604 marine biology & hydrobiology, Microorganism, Zoology, Pelagic zone, Biology, Seasonality, Plankton, medicine.disease, biology.organism_classification, 01 natural sciences, Applied Microbiology and Biotechnology, Microbiology, Population density, 03 medical and health sciences, Microbial ecology, medicine, 14. Life underwater, Viral disease, Bacteria
Abstract: The ecology of viruses in shallow artificial freshwaters is poorly documented and there is no reference for sand pit lakes. We examined the seasonal abundances and infection rates of viruses in the sand pit Lake Creteil (France). Bacteria were the best predictor of viral abundance (4.0-7.8 × 10(10) viruses L(-1) ), with an average virus-to-bacteria ratio of 13.5 ± 1.9. Virus-induced bacterial mortality (range 37-86%, mean 65%) was higher than that in typical pelagic situations. This was related to high specific contact rates between viruses and bacterial hosts and high burst size (BS) estimates. Seasonal fluctuations in viruses and bacteria were rather homeostatic, although temperature was a major driver of microbial activities. Different bacterial morphotypes, i.e. 'morphopopulations', were analysed. Rod cells dominated the total (90%) and infected (89%) communities. Elongated rods were the most infected (45% of infected cells), whereas fat rods exhibited the highest BS estimates (mean=72 viruses per bacterium) due to a larger specific cell volume. We conclude that the lytic activity of viruses is high and heterogeneous for different bacterial-host phenotypes in the sand pit Lake Creteil. A theoretical exercise shows that this can exert a strong influence on the processes occurring in plankton food webs.
Published: 2010
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16. The significance of transparent exopolymeric particles in the vertical distribution of bacteria and heterotrophic nanoflagellates in Lake Pavin

Author: Nicolas Courcol, Mohamad-Bashir Arnous, and Jean-François Carrias
Subjects: Ecology, Particle (ecology), Aquatic Science, Sedimentation, Plankton, Biology, biology.organism_classification, Water column, Diatom, Phytoplankton, Particle size, Hypolimnion, Ecology, Evolution, Behavior and Systematics, Water Science and Technology
Abstract: The abundance, size distribution, and bacterial colonization of Transparent Exopolymeric Particles (TEP) were examined in two consecutive years during the spring diatom development throughout the water column of the deep meromictic Lake Pavin, France. TEP concentrations ranged from 1.9 to 13.4 × 105 particles l−1 and their distribution and size spectra indicated that these particles are the main factor in governing the transport of diatoms to the deep hypolimnion of the lake. The majority of TEP was colonized by bacteria that constituted 0.4–8.9% of total DAPI-stained bacteria. The intensity of bacterial colonization was strongly related to temperature and decreased with particle size. A more important colonization of small particles in the hypolimnion during thermal stratification suggested that bacterial colonisation also increased with the age of the particle. The abundance of heterotrophic nanoflagellates (HNF) was more significantly related to the density of particles than to the density of total bacteria and the intensity of bacterial colonization of TEP. Our results therefore suggest that TEP are a more important factor for HNF development than attached and free bacteria. We conclude that TEP are involved not only in sedimentation processes but also in the dynamics of bacteria and protozoa in freshwater pelagic environments.
Published: 2010
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17. The contribution of microorganisms and metazoans to mineral nutrition in bromeliads

Author: Bruno Corbara, Régis Céréghino, Jean-François Carrias, Céline Leroy, Ecologie des forêts de Guyane (UMR ECOFOG), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-AgroParisTech-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Université de Clermont-Ferrand, Laboratoire Microorganismes : Génome et Environnement - Clermont Auvergne (LMGE), Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, La Région Guyane, Investissement d'avenir CEBA : ANR 10 LABX 0025, Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Université des Antilles (UA)-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-AgroParisTech-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD [France-Sud]), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020]), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), and Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP)
Subjects: 0106 biological sciences, Range (biology), [SDV]Life Sciences [q-bio], Plant Science, Biology, 010603 evolutionary biology, 01 natural sciences, multiple N sources, Nutrient, Forest ecology, Botany, forest ecology, Ecology, Evolution, Behavior and Systematics, 2. Zero hunger, myrmecotrophy, Ecology, food and beverages, 15. Life on land, digestive mutualism, Myrmecotrophy, Trichome, écologie forestière, leaf delta N-15, Habitat, Epiphyte, Adaptation, multiple N source, 010606 plant biology & botany, insect-assisted nutrients
Abstract: Aims One critical challenge for plants is to maintain an adequate nutrient supply under fluctuating environmental conditions. This is particularly true for epiphytic species that have limited or no access to the pedosphere and often live in harsh climates. Bromeliads have evolved key innovations such as epiphytism, water-absorbing leaf trichomes, tank habit and Crassulacean acid metabolism (CAM) photosynthesis that enable them to survive under various environmental conditions. Bromeliads encompass diverse ecological types that live on different substrates (they can be terrestrial, epilithic or epiphytic) and vary in their ability to retain water (they can be tank-forming or tankless) and photosynthetic pathway (i.e. C3 or CAM). In this review, we outline the nutritional modes and specializations that enable bromeliads to thrive in a wide range of nutrient-poor (mostly nitrogen-depleted) environments. Important Findings Bromeliads have evolved a great diversity of morphologies and functional adaptations leading to the existence of numerous nutritional modes. Focusing on species that have absorptive foliar trichomes, we review evidence that bromeliads have evolved multi-faceted nutritional strategies to respond to fluctuations in the supply of natural nitrogen (N). These plants have developed mutualistic associations with many different and functionally diverse terrestrial and aquatic microorganisms and metazoans that contribute substantially to their mineral nutrition and, thus, their fitness and survival. Bacterial and fungal microbiota-assisted N provisioning, protocarnivory, digestive mutualisms and myrmecotrophic pathways are the main strategies used by bromeliads to acquire nitrogen. The combination of different nutritional pathways in bromeliads represents an important adaptation enabling them to exploit nutrient-poor habitats. Nonetheless, as has been shown for several other vascular plants, multiple partners are involved in nutrient acquisition indicating that there have been convergent adaptations to nutrient scarcity. Finally, we point out some gaps in the current knowledge of bromeliad nutrition that offer fascinating research opportunities.
Published: 2016
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18. Composition and distribution of planktonic ciliates from ponds of different salinity in the solar saltwork of Sfax, Tunisia

Author: Habib Ayadi, Télesphore Sime-Ngando, Mekki Boukhris, Jean-François Carrias, Jannet Elloumi, Abderrahmen Bouain, UR Biodiversité & Ecosystèmes Aquatiques, University of Sfax, Laboratoire Microorganismes : Génome et Environnement ( LMGE ), Université Blaise Pascal - Clermont-Ferrand 2 ( UBP ) -Centre National de la Recherche Scientifique ( CNRS ) -Université d'Auvergne - Clermont-Ferrand I ( UdA ), Laboratoire Chrono-environnement ( LCE ), Université Bourgogne Franche-Comté ( UBFC ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Franche-Comté ( UFC ), Université de Sfax - University of Sfax, Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université d'Auvergne - Clermont-Ferrand I (UdA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Chrono-environnement (UMR 6249) (LCE), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)-Université d'Auvergne - Clermont-Ferrand I (UdA), and Laboratoire Chrono-environnement - CNRS - UBFC (UMR 6249) (LCE)
Subjects: 0106 biological sciences, solar saltwork, Brine shrimp, Aquatic Science, Oceanography, 010603 evolutionary biology, 01 natural sciences, salinity gradient, protozoa, 14. Life underwater, Ciliate, [ SDE.BE ] Environmental Sciences/Biodiversity and Ecology, biology, Ecology, 010604 marine biology & hydrobiology, fungi, Plankton, biology.organism_classification, Halophile, Salinity, Halotolerance, Protozoa, ciliates, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Artemia salina, halophile
Abstract: International audience; The planktonic ciliated protozoa of 14 ponds of increasing salinity were investigated in the saline of Sfax, Tunisia. Taxa of the classes of Spirotrichea and Heterotrichea were the numerous ciliates. Abundance of the community ranged from 0.0 to 11.8 × 104 ciliates per litre. Values decrease significantly with salinity gradient, as species richness does. Based on the range of salinity over which ciliate taxa appeared, we distinguished three groups of ciliates. The first group is mainly composed of oligotrichs and choreotrichs that are commonly found in marine coastal waters. Small ciliates belonging to the order Prostomatida were found in a large range of salinity values, but their densities also decreased with salt concentration. In contrast, large-size species of heterotrichous ciliates were found in ponds with high salinity values only. In these ponds, the presence of prey appeared as an important factor in controlling the abundances of these halotolerant ciliates. Our data also suggest that Fabrea salina, a common halophile ciliate, acts as a competitor of the brine shrimp Artemia salina in the saline of Sfax. Salinity, prey availability, and the presence of competitors seem to be the main factors for the distribution of ciliate taxa in this hypersaline environment.
Published: 2006
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19. A Preliminary Study of Heterotrophic Picoflagellates Using Oligonucleotidic Probes in Lake Pavin

Author: Télesphore Sime-Ngando, Christian Amblard, Emilie Lefèvre, Corinne Bardot, Jean-François Carrias, Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)-Université d'Auvergne - Clermont-Ferrand I (UdA), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université d'Auvergne - Clermont-Ferrand I (UdA)-Centre National de la Recherche Scientifique (CNRS), and Sime-Ngando, Télesphore
Subjects: 0106 biological sciences, Functional role, 0303 health sciences, 030306 microbiology, Ecology, 010604 marine biology & hydrobiology, Heterotroph, Aquatic environment, Aquatic Science, Biology, Ribosomal RNA, Probe, 01 natural sciences, [SDE.BE] Environmental Sciences/Biodiversity and Ecology, Lakes, 03 medical and health sciences, Abundance (ecology), %22">Fish , Seawater, Hydrobiology, 14. Life underwater, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Eucaryote
Abstract: International audience; Free-living heterotrophic flagellates have been widely studied as key intermediates in aquatic food webs. However, very few attempts have been made (all in marine systems) to study the smallest cells belonging to these communities. In this study, we report on the quantitative importance and the vertical distribution of heterotrophic picoflagellates during spring in the oligomesotrophic Lake Pavin, using the FISH approach. The rRNA-based probes used, initially designed for two novel lineages of heterotrophic picoflagellates (i.e., the Stramenopiles NS3 and NS4) in marine systems, revealed high abundances (in the order of 104 cells ml-1 and up to about 6 x 104 cells ml-1) of the targeted picoflagellates in Lake Pavin, i.e. one order of magnitude higher than in seawater samples. 'NS3' cells were more often detected than 'NS4' cells, the average contributions of the two populations to the total abundance of heterotrophic flagellates being at 25 and 9%, respectively. However, the probes used were apparently non-specific to the targeted cells, implying that the occurrence of the two novel lineages NS3 and NS4 of Stramenopiles in freshwaters needs to be confirmed. Although, this study clearly confirms the occurrence, in high abundance, of small heterotrophic eukaryotes in Lake Pavin. In a near future, we believe that the availability of microbial clone libraries will allow us to improve our knowledge of the composition and the functional role of small heterotrophic eukaryotes in freshwaters.
Published: 2005
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20. Virioplankton and microbial communities in aquatic systems: a seasonal study in two lakes of differing trophy

Author: Yvan Bettarel, Christian Amblard, Christophe Portelli, Jean-François Carrias, and Télesphore Sime-Ngando
Subjects: 0106 biological sciences, 0303 health sciences, 030306 microbiology, Ecology, viruses, 010604 marine biology & hydrobiology, Aquatic ecosystem, Aquatic Science, Plankton, Biology, 01 natural sciences, 03 medical and health sciences, Water column, Microbial population biology, Abundance (ecology), parasitic diseases, Eutrophication, Relative species abundance, Trophic level
Abstract: 1. The seasonal and vertical distribution of the abundance of virus-like particles (VLPs), together with the abundances of other microbial organisms (bacteria, unpigmented and pigmented nanoflagellates and ciliates), were determined in an oligomesotrophic lake (Pavin, France) and in a eutrophic lake (Aydat, France) between March and December 2000. 2. The abundance of the viral plankton and those of other microbial taxa were significantly higher in the more productive system. The same was for the virus-to-bacteria quotient (VBQ), which averaged seven in Lake Pavin and nine in Lake Aydat. 3. The abundance of viruses increased during the period of thermal stratification in both lakes, with the highest values being recorded at the end of summer/early autumn in the epi- and the metalimnion. The seasonal pattern of abundance of viruses in both lakes in the surface layer was similar, indicating that the dynamics of viruses may be controlled by environmental factors such as light conditions. 4. There was no correlation between the abundance of viruses and protists. We found correlations between viruses and heterotrophic bacteria in the whole water column in Lake Pavin, but only in the dark bottom waters in Lake Aydat. 5. Overall, the empirical findings in this study lead us to speculate that the weaker correlation between bacteria and viruses in Lake Aydat than in Lake Pavin, as well as the higher VBQ in the former, is a consequence of the increasing relative abundance of non-bacteriophage VLPs along the trophic gradient of aquatic systems.
Published: 2003
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21. Effects of commonly used fixatives on size parameters of freshwater planktonic protists

Author: Olivier Chaput and Jean-François Carrias
Subjects: Ecology, biology, Ciliata, fungi, Heterotroph, Formaldehyde, chemistry.chemical_element, Aquatic Science, Plankton, biology.organism_classification, Iodine, Chloride, chemistry.chemical_compound, Animal science, chemistry, medicine, Protozoa, Glutaraldehyde, Ecology, Evolution, Behavior and Systematics, medicine.drug
Abstract: We tested the effect of four commonly used fixatives (Lugol's iodine, mercuric chloride, glutaraldehyde and formaldehyde) on cell length, width and volume of six species of freshwater planktonic protists. Most of the fixatives significantly influenced the cell dimensions of these species. Significant changes in the volume of protists, expressed as a percent of the average live cell volume, ranged from -64 to +59%. Changes in cell volume were highest for heterotrophic flagellates and scuticociliates, indicating that the biomass of these protists in freshwater systems has probably been underestimated in experiments in which volume estimates were based on fixed samples. The effects were, in the order of increasing change in cell parameters: formaldehyde < glutaraldehyde < Lugol's iodine < mercuric chloride. We observed differences between taxa in their response to the same treatment, particularly for the mercuric chloride fixation. In addition, opposite responses were noted for the scuticociliate species. In the light of our study and other works, we recommend the application of conversion factors of 1.4 and 1.7 for Lugol's and glutaraldehyde-fixed cells, respectively, to accurately estimate the biovolume of protists in fixed samples.
Published: 2002
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22. Two coexisting tank bromeliads host distinct algal communities on a tropical inselberg

Author: A. Couté, Bruno Corbara, Alain Dejean, Régis Céréghino, Céline Leroy, Laurent Pélozuelo, Olivier Brouard, Jean-François Carrias, Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), UPS CNRS Guyane (UCG), Centre National de la Recherche Scientifique (CNRS), Muséum national d'Histoire naturelle (MNHN), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Goose & Duck Breeding Stn, Association des Eleveurs de Dordogne (Asseldor), Laboratoire Microorganismes : Génome et Environnement - Clermont Auvergne (LMGE), Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, UPS 2561 GUYANE, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD [France-Sud])
Subjects: Bromeliaceae, Catopsis, Population, Population Dynamics, Fresh Water, Plant Science, Chlorella, Biology, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Algae, Abundance (ecology), Botany, 14. Life underwater, Biomass, education, Symbiosis, Ecology, Evolution, Behavior and Systematics, Ecosystem, Phylogeny, ComputingMilieux_MISCELLANEOUS, Invertebrate, Abiotic component, Population Density, education.field_of_study, Biomass (ecology), Detritus, Ecology, General Medicine, Biodiversity, 15. Life on land, biology.organism_classification, French Guiana, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Stramenopiles, [SDV.EE.IEO]Life Sciences [q-bio]/Ecology, environment/Symbiosis
Abstract: The tank bromeliads Aechmea aquilega (Salisb.) and Catopsis berteroniana (Schultes f.) coexist on a sun-exposed Neotropical inselberg in French Guiana, where they permit conspicuous freshwater pools to form that differ in size, complexity and detritus content. We sampled the algal communities (both eukaryotic and cyanobacterial taxa, including colourless forms) inhabiting either A. aquilega (n = 31) or C. berteroniana (n = 30) and examined differences in community composition and biomass patterns in relation to several biotic and abiotic variables. Chlorella sp. and Bumilleriopsis sp. were the most common taxa and dominated the algal biomass in A. aquilega and C. berteroniana, respectively. Using a redundancy analysis, we found that water volume, habitat complexity and the density of phagotrophic protozoa and collector-gatherer invertebrates were the main factors explaining the distribution of the algal taxa among the samples. Hierarchical clustering procedures based on abundance and presence/absence data clearly segregated the samples according to bromeliad species, revealing that the algal communities in the smaller bromeliad species were not a subset of the communities found in the larger bromeliad species. We conclude that, even though two coexisting tank bromeliad populations create adjacent aquatic habitats, each population hosts a distinct algal community. Hence, bromeliad diversity is thought to promote the local diversity of freshwater algae in the Neotropics.
Published: 2014
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23. Seasonal dynamics of free and attached heterotrophic nanoflagellates in an oligomesotrophic lake

Author: Catherine Quiblier-Lloberas, Jean-François Carrias, Gilles Bourdier, and Christian Amblard
Subjects: biology, Algae, Abundance (ecology), Ecology, Epilimnion, Phytoplankton, Bacterioplankton, Aquatic Science, Flagellate, biology.organism_classification, Zooplankton, Copepod
Abstract: 1. The seasonal development of heterotrophic nanoflagellates (HNF), bacteria, rotiferans and crustacean zooplankton was studied in the epilimnion of Lake Pavin, an oligomesotrophic lake in the Massif Central of France. 2. HNF abundance varied from 0.1 to 2.5 × 103 mL–1. Free-living HNF reached their highest density in spring when the copepod Acanthodiaptomus denticornis dominated the metazooplankton. They were present in low numbers when rotifers and cladocerans were numerous. 3. Attached HNF, consisting of bicoecids and choanoflagellates, were fixed to large diatoms and to the colonial cyanobacterium Anabaena flos-aquae. The abundance of attached HNF was significantly correlated to bacterial abundance, which fluctuated between 1.1 and 2.7 × 106 mL–1. Highest abundance of these epiphytic protists was recorded when free-living heterotrophic nanoflagellates declined. 4. The comparison of the dynamics of heterotrophic nanoflagellates, bacteria, and the impact of zooplankton grazing suggested that prey abundance, the presence of suitable attachment sites and limited competition from the free-living forms were the main factors controlling the development of the epiphytic flagellate protists. In contrast, the low abundance of free-living forms during the period of rotiferan and cladoceran development suggests the prevalence of a top-down control by predation of the metazoopankton.
Published: 1998
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24. Environmental determinants of macroinvertebrate diversity in small water bodies : insights from tank-bromeliads

Author: Olivier Dézerald, Bruno Corbara, Alain Dejean, Céline Leroy, Jean-François Carrias, Régis Céréghino, Stanislas Talaga, Ecologie des forêts de Guyane (UMR ECOFOG), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-AgroParisTech-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Université Blaise Pascal (Clermont Ferrand 2) (UBP), PRES Université de Clermont, Laboratoire Microorganismes : Génome et Environnement - Clermont Auvergne (LMGE), Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, ‘‘Investissement d’Avenir’’ grant managed by Agence Nationale de la Recherche (CEBA) [ANR-10- LABX-0025], AgroParisTech (FRANCE), Centre de Coopération Internationale en Recherche Agronomique - CIRAD (FRANCE), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National de la Recherche Agronomique - INRA (FRANCE), Institut de Recherche pour le Développement - IRD (FRANCE), Université Blaise Pascal - UBP (FRANCE), Université des Antilles et de la Guyane (FRANCE), Microorganismes : Génome et Environnement - LMGE (Aubière, France), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD [France-Sud]), Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Université des Antilles (UA)-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-AgroParisTech-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA), Laboratoire de Chimie des polymères organiques (LCPO), Université Sciences et Technologies - Bordeaux 1-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Centre National de la Recherche Scientifique (CNRS), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)-Université d'Auvergne - Clermont-Ferrand I (UdA), Ecologie des forêts de Guyane (ECOFOG), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université des Antilles et de la Guyane (UAG)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université d'Auvergne - Clermont-Ferrand I (UdA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), and Université de Toulouse (UT)
Subjects: 0106 biological sciences, Microcosms, Range (biology), Biodiversité et Ecologie, [SDV]Life Sciences [q-bio], Aquatic Science, Biology, 010603 evolutionary biology, 01 natural sciences, Predation, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Abundance (ecology), Ponds, ComputingMilieux_MISCELLANEOUS, Invertebrate, Detritus, Phytotelmata, Ecology, 010604 marine biology & hydrobiology, fungi, Detritivore, Community structure, Freshwater biodiversity Linear mixed effect modelling Microcosms Phytotelmata Ponds, 15. Life on land, Freshwater biodiversity, Zoologie des invertébrés, 6. Clean water, Linear mixed effect modelling, Habitat, Ecosystèmes, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, [SDV.EE.IEO]Life Sciences [q-bio]/Ecology, environment/Symbiosis
Abstract: International audience; 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.
Published: 2014
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25. Food-web structure in relation to environmental gradients and predator-prey ratios in tank-bromeliad ecosystems

Author: Régis Céréghino, Jean-François Carrias, Alain Dejean, Bruno Corbara, Olivier Dézerald, Céline Leroy, Laurent Pélozuelo, Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université d'Auvergne - Clermont-Ferrand I (UdA)-Centre National de la Recherche Scientifique (CNRS), Programme Amazonie II of the French Centre National de la Recherche Scientifique (Project 2ID), Programme Convergence 2007–2013 (Région Guyane) from the European Community (Project DEGA), 'Investissement d’Avenir' grant managed by Agence Nationale de la Recherche (CEBA) [ANR-10-LABX-0025], CNRS, FSE (Fond Social Européen), AgroParisTech (FRANCE), Centre de Coopération Internationale en Recherche Agronomique - CIRAD (FRANCE), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Institut National de la Recherche Agronomique - INRA (FRANCE), Institut de Recherche pour le Développement - IRD (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université Blaise Pascal - UBP (FRANCE), Université des Antilles et de la Guyane (FRANCE), Microorganismes : Génome et Environnement - LMGE (Aubière, France), École normale supérieure - Paris (ENS Paris), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD [France-Sud]), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)-Université d'Auvergne - Clermont-Ferrand I (UdA), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), École normale supérieure - Paris (ENS Paris)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Dézerald, Olivier
Subjects: 0106 biological sciences, Biodiversité et Ecologie, Population Dynamics, Biodiversity, lcsh:Medicine, Generalist and specialist species, 01 natural sciences, Food chain, Predator-Prey Dynamics, Food Web Structure, Community Assembly, lcsh:Science, Freshwater Ecology, [SDV.EE]Life Sciences [q-bio]/Ecology, environment, Multidisciplinary, Geography, Ecology, Environmental gradients, Food web, Trophic Interactions, French Guiana, Habitat, Community Ecology, Nestedness, Research Article, Freshwater Environments, Food Chain, Tank-bromeliads, Bromelia, Biology, 010603 evolutionary biology, Models, Biological, Ecosystems, Predators prey ratios, Animals, Community Structure, Ecologie, Environnement, Population Biology, 010604 marine biology & hydrobiology, lcsh:R, Detritivore, Species diversity, Bayes Theorem, 15. Life on land, Food-web structure, Zoologie des invertébrés, [SDV.BA.ZI]Life Sciences [q-bio]/Animal biology/Invertebrate Zoology, Species Interactions, Predatory Behavior, lcsh:Q, Population Ecology, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Ecological Environments
Abstract: International audience; 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.
Published: 2013
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26. Mutualistic ants contribute to tank-bromeliad nutrition

Author: Bruno Corbara, Régis Céréghino, Laurent Pélozuelo, Alain Dejean, Olivier Brouard, Céline Leroy, Jean-François Carrias, Olivier Dézerald, AgroParisTech (FRANCE), Centre de Coopération Internationale en Recherche Agronomique - CIRAD (FRANCE), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut National de la Recherche Agronomique - INRA (FRANCE), Institut de Recherche pour le Développement - IRD (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université Blaise Pascal - UBP (FRANCE), Université des Antilles et de la Guyane (FRANCE), Microorganismes : Génome et Environnement - LMGE (Aubière, France), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université d'Auvergne - Clermont-Ferrand I (UdA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Ecologie des forêts de Guyane (ECOFOG), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université des Antilles et de la Guyane (UAG)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), Institut National Polytechnique de Toulouse - INPT (FRANCE), Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), ‘Investissement d’Avenir’ grant managed by Agence Nationale de la Recherche (CEBA) [ANR-10-LABX-0025], Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD [France-Sud]), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)-Université d'Auvergne - Clermont-Ferrand I (UdA), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), and Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, Bromeliaceae, δ¹⁵N, tank bromeliad, Biodiversité et Ecologie, Plant Science, 01 natural sciences, nitrogen, Predation, d15N, Nutrient, Photosynthesis, Predator, delta N-15, Trophic level, Stable isotopes, 2. Zero hunger, chemistry.chemical_classification, biology, Ecology, Food webs, food and beverages, Food web, French Guiana, Algae, Nitrogen, stable isotopes, ants, Formicinae, 010603 evolutionary biology, Botany, Animals, Organic matter, Symbiosis, Ecologie, Environnement, Phytotelmata, Nitrogen Isotopes, Ants, fungi, mutualistic interactions, Water, Original Articles, 15. Life on land, biology.organism_classification, Myrmecotrophy, Zoologie des invertébrés, Tank bromeliad, Mutualistic interactions, chemistry, food webs, phytotelmata, 010606 plant biology & botany, [SDV.EE.IEO]Life Sciences [q-bio]/Ecology, environment/Symbiosis
Abstract: International audience; Background and AimsEpiphytism imposes physiological constraints resulting from the lack of access to the nutrient sources available to ground-rooted plants. A conspicuous adaptation in response to that lack is the phytotelm (plant-held waters) of tank-bromeliad species that are often nutrient-rich. Associations with terrestrial invertebrates also result in higher plant nutrient acquisition. Assuming that tank-bromeliads rely on reservoir-assisted nutrition, it was hypothesized that the dual association with mutualistic ants and the phytotelm food web provides greater nutritional benefits to the plant compared with those bromeliads involved in only one of these two associations.MethodsQuantitative (water volume, amount of fine particulate organic matter, predator/prey ratio, algal density) and qualitative variables (ant-association and photosynthetic pathways) were compared for eight tank- and one tankless-bromeliad morphospecies from French Guiana. An analysis was also made of which of these variables affect nitrogen acquisition (leaf N and δ(15)N).Key ResultsAll variables were significantly different between tank-bromeliad species. Leaf N concentrations and leaf δ(15)N were both positively correlated with the presence of mutualistic ants. The amount of fine particulate organic matter and predator/prey ratio had a positive and negative effect on leaf δ(15)N, respectively. Water volume was positively correlated with leaf N concentration whereas algal density was negatively correlated. Finally, the photosynthetic pathway (C3 vs. CAM) was positively correlated with leaf N concentration with a slightly higher N concentration for C3-Tillandsioideae compared with CAM-Bromelioideae.ConclusionsThe study suggests that some of the differences in N nutrition between bromeliad species can be explained by the presence of mutualistic ants. From a nutritional standpoint, it is more advantageous for a bromeliad to use myrmecotrophy via its roots than to use carnivory via its tank. The results highlight a gap in our knowledge of the reciprocal interactions between bromeliads and the various trophic levels (from bacteria to large metazoan predators) that intervene in reservoir-assisted nutrition.
Published: 2013
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27. An ant-plant mutualism induces shifts in the protist community structure of a tank-bromeliad

Author: Laurent Pélozuelo, Alain Dejean, Céline Leroy, Jean-François Carrias, Bruno Corbara, Régis Céréghino, Olivier Brouard, AgroParisTech (FRANCE), Centre de Coopération Internationale en Recherche Agronomique - CIRAD (FRANCE), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut National de la Recherche Agronomique - INRA (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université Blaise Pascal - UBP (FRANCE), Université des Antilles et de la Guyane (FRANCE), Ecologie des Forêts de Guyane - EcoFoG (Kourou, Guyane), Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)-Université d'Auvergne - Clermont-Ferrand I (UdA), Ecologie des forêts de Guyane (ECOFOG), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université des Antilles et de la Guyane (UAG)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées, Institut National Polytechnique de Toulouse - INPT (FRANCE), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université d'Auvergne - Clermont-Ferrand I (UdA)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), IST, Centre d'Etude et de Recherche de Djibouti (CERD), CERD, Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), French Centre National de la Recherche Scientifique (Project 2ID of the programme Amazonie II), and Fondation pour la Recherche sur la Biodiversité (Project MICBROME) [AAPIN-2009-038]
Subjects: 0106 biological sciences, Biodiversité et Ecologie, Biodiversity, Biology, medicine.disease_cause, 010603 evolutionary biology, 01 natural sciences, [SDV.MP.PRO]Life Sciences [q-bio]/Microbiology and Parasitology/Protistology, Camponotus femoratus, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Myrmecophyte, medicine, Aechmea mertensii, Ant-garden, Ecology, Evolution, Behavior and Systematics, Mutualism (biology), Protist communities, Microbial food web, Phytotelmata, Ecology, 010604 marine biology & hydrobiology, Community structure, Protist, Protists, 15. Life on land, Zoologie des invertébrés, Pachycondyla goeldii, French Guiana, [SDV.BA.ZI]Life Sciences [q-bio]/Animal biology/Invertebrate Zoology, Protist richness, Habitat, Ant-plant, Ecosystèmes, Epiphyte, Species richness, [SDE.BE]Environmental Sciences/Biodiversity and Ecology
Abstract: International audience; Although ants may induce community-wide effects via changes in physical habitats in terrestrial environments, their influence on aquatic communities living in plant-held waters remains largely underexplored. The neotropical tank-bromeliad Aechmea mertensii (Bromeliaceae) occurs along forest edges in ant-gardens initiated by Camponotus femoratus or by Pachycondyla goeldii. Its leaves form wells that hold rainwater and provide suitable habitats for many aquatic organisms. We postulated that these ant-plant mutualisms indirectly affect the microbial community structure via changes in the environmental conditions experienced by the plants. To test this hypothesis, we analyzed the protist communities from 63 tank-bromeliads associated with either C. femoratus or P. goeldii (hereafter Cf-Aechmea and Pg-Aechmea) along a forest edge in French Guiana. For each plant, a large number of environmental variables (including habitat structure, food resources, incident radiation and the presence of aquatic invertebrates) were quantified to determine their relative importance in driving any observed differences across ant-associated plants. Pg-Aechmea are located in sun-exposed areas and hold low volumes of water and low amounts of detritus, whereas Cf-Aechmea are located in partially shaded areas and accumulate higher amounts of water and detritus. Protists (i.e., protozoa and algae) inhabiting Cf-Aechmea exhibit greater richness and abundances than those in Pg-Aechmea. Variations in detritus content, number of leaves, incident radiation, and the epiphyte richness of the ant-garden were the main factors explaining the variation in protist richness. A shift in the functional group composition of protists between bromeliads tended by different ant species suggested that mutualistic ants indirectly mediate changes in the microbial food web.
Published: 2012
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28. Ant species identity mediates reproductive traits and allocation in an ant-garden bromeliad

Author: Laurent Pélozuelo, Alain Dejean, Jean-François Carrias, Régis Céréghino, Bruno Corbara, Céline Leroy, AgroParisTech (FRANCE), Centre de Coopération Internationale en Recherche Agronomique - CIRAD (FRANCE), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Institut National de la Recherche Agronomique - INRA (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université Blaise Pascal - UBP (FRANCE), Université des Antilles et de la Guyane (FRANCE), Microorganismes : Génome et Environnement - LMGE (Aubière, France), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Ecologie des forêts de Guyane (ECOFOG), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université des Antilles et de la Guyane (UAG)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université d'Auvergne - Clermont-Ferrand I (UdA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Université Toulouse III - Paul Sabatier (UT3), Programme Amazonie II of the French Centre National de la Recherche Scientifique (Project 2ID), Programme Convergence 2007–2013 (Région Guyane) from the European Community (Project DEGA), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)-Université d'Auvergne - Clermont-Ferrand I (UdA), Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), and Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP)
Subjects: 0106 biological sciences, Bromeliaceae, Pollination, Genetic Speciation, Nitrogen, Seed dispersal, Biodiversité et Ecologie, Flowers, Plant Science, Biology, 010603 evolutionary biology, 01 natural sciences, Camponotus femoratus, Pollinator, Floral traits, Seed Dispersal, Animals, Aechmea mertensii, Reproductive allocation, delta N-15, D15N, Stable isotopes, Plant evolution, Abiotic component, Ecologie, Environnement, Ants, Ecology, Original Articles, biology.organism_classification, Biological Evolution, Zoologie des invertébrés, Fruit-set, French Guiana, Pachycondyla goeldii, Inflorescence, Fruit, Seeds, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Mutualistic ants, Bromeliad, 010606 plant biology & botany
Abstract: International audience; BACKGROUND AND AIMS: Determining the sources of variation in floral morphology is crucial to understanding the mechanisms underlying Angiosperm evolution. The selection of floral and reproductive traits is influenced by the plant's abiotic environment, florivores and pollinators. However, evidence that variations in floral traits result from mutualistic interactions with insects other than pollinators is lacking in the published literature and has rarely been investigated. We aimed to determine whether the association with either Camponotus femoratus or Pachycondyla goeldii (both involved in seed dispersal and plant protection) mediates the reproductive traits and allocation of Aechmea mertensii, an obligatory ant-garden tank-bromeliad, differently. METHODS: Floral and reproductive traits were compared between the two A. mertensii ant-gardens. The nitrogen flux from the ants to the bromeliads was investigated through experimental enrichments with stable isotopes ((15)N). KEY RESULTS: Camponotus femoratus-associated bromeliads produced inflorescences up to four times longer than did P. goeldii-associated bromeliads. Also, the numbers of flowers and fruits were close to four times higher, and the number of seeds and their mass per fruit were close to 1*5 times higher in C. femoratus than in P. goeldii-associated bromeliads. Furthermore, the (15)N-enrichment experiment showed that C. femoratus-associated bromeliads received more nitrogen from ants than did P. goeldii-associated bromeliads, with subsequent positive repercussions on floral development. Greater benefits were conferred to A. mertensii by the association with C. femoratus compared with P. goeldii ants. CONCLUSIONS: We show for the first time that mutualistic associations with ants can result in an enhanced reproductive allocation for the bromeliad A. mertensii. Nevertheless, the strength and direction of the selection of floral and fruit traits change based on the ant species and were not related to light exposure. The different activities and ecological preferences of the ants may play a contrasting role in shaping plant evolution and speciation.
Published: 2012
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29. Vertical and temporal heterogeneity of planktonic ciliated protozoa in a humic lake

Author: Christian Amblard, Gilles Bourdier, and Jean-François Carrias
Subjects: Biomass (ecology), Ecology, Ciliated protozoa, biology, Ciliata, Aquatic Science, Plankton, Seasonality, biology.organism_classification, medicine.disease, Temporal heterogeneity, Food supply, medicine, Protozoa, Ecology, Evolution, Behavior and Systematics
Published: 1994
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30. Are Algae Relevant to the Detritus-Based Food Web in Tank-Bromeliads?

Author: Anne-Hélène Le Jeune, Olivier Brouard, Régis Céréghino, Bruno Corbara, Olivier Roux, Jean-François Carrias, Alain Dejean, Laurent Pélozuelo, Céline Leroy, Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université d'Auvergne - Clermont-Ferrand I (UdA)-Centre National de la Recherche Scientifique (CNRS), Ecologie des forêts de Guyane (ECOFOG), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université des Antilles et de la Guyane (UAG)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, AgroParisTech (FRANCE), Centre de Coopération Internationale en Recherche Agronomique - CIRAD (FRANCE), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut National de la Recherche Agronomique - INRA (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de la Méditerranée - Aix-Marseille II (FRANCE), Université des Antilles et de la Guyane (FRANCE), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)-Université d'Auvergne - Clermont-Ferrand I (UdA), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Programme Amazonie II of the French Centre National de la Recherche Scientifique (Project 2ID), Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), and Institut National Polytechnique de Toulouse - INPT (FRANCE)
Subjects: 0106 biological sciences, Biodiversité et Ecologie, lcsh:Medicine, Aquatic ecosystem, Plant Science, 01 natural sciences, Food chain, Food Web Structure, Grazing, Relative Abundance Distribution, lcsh:Science, Freshwater Ecology, Biomass (ecology), Multidisciplinary, biology, Primary producers, Ecology, Biodiversity, Plants, Biota, Food web, Trophic Interactions, Botanique, Ecosystèmes, Community Ecology, Ecosystem Functioning, Research Article, Freshwater Environments, Catopsis, Food Chain, Ecological Metrics, Algae, Biomass (Ecology), Bromelia, Primary rainforest, Aquatic food web, Insectivorous, 010603 evolutionary biology, Microbiology, Ecosystems, Microbial Ecology, Species Specificity, Plant-Environment Interactions, Botany, Biology, Community Structure, 010604 marine biology & hydrobiology, Plant Ecology, lcsh:R, fungi, Phytotelm plants, 15. Life on land, biology.organism_classification, Bromeliads, lcsh:Q, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Ecological Environments
Abstract: International audience; We assessed the occurrence of algae in five species of tank-bromeliads found in contrasting environmental sites in a Neotropical, primary rainforest around the Nouragues Research Station, French Guiana. The distributions of both algal abundance and biomass were examined based on physical parameters, the morphological characteristics of bromeliad species and with regard to the structure of other aquatic microbial communities held in the tanks. Algae were retrieved in all of the bromeliad species with mean densities ranging from ∼10(2) to 10(4) cells/mL. Their biomass was positively correlated to light exposure and bacterial biomass. Algae represented a tiny component of the detrital food web in shaded bromeliads but accounted for up to 30 percent of the living microbial carbon in the tanks of Catopsis berteroniana, located in a highly exposed area. Thus, while nutrient supplies are believed to originate from wind-borne particles and trapped insects (i.e., allochtonous organic matter), our results indicate that primary producers (i.e., autochtonous organic matter) are present in this insectivorous bromeliad. Using a 24-h incubation of size-fractionated and manipulated samples from this plant, we evaluated the impact of mosquito foraging on algae, other microorganisms and rotifers. The prey assemblages were greatly altered by the predation of mosquito larvae. Grazing losses indicated that the dominant algal taxon, Bumilleriopsis sp., like protozoa and rotifers, is a significant part of the diet of mosquito larvae. We conclude that algae are a relevant functional community of the aquatic food web in C. berteroniana and might form the basis of a complementary non-detrital food web.
Published: 2011
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31. Bacteria, Attached to Surfaces

Author: Jean-François Carrias, Télesphore Sime-Ngando, Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)-Université d'Auvergne - Clermont-Ferrand I (UdA), and Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université d'Auvergne - Clermont-Ferrand I (UdA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Inland waters, Microbial diversity, Microorganism, Attachment, Bacterial adhesion, Biology, Sessile bacteria, 03 medical and health sciences, Extracellular polymeric substance, Microbial mats, Organic matter, 14. Life underwater, Microbial mat, 030304 developmental biology, chemistry.chemical_classification, Freshwaters, 0303 health sciences, 030306 microbiology, Ecology, Aquatic ecosystem, Biofilm, Organic aggregates, Surface colonization, Bacteroidetes, 15. Life on land, biology.organism_classification, Fixed bacteria, chemistry, Microbial consortia, 13. Climate action, Biofilms, Attached bacteria, Epiphytic communities, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Bacteria
Abstract: The occurrence of bacteria attached to surfaces is characteristic of world inland water habitats. Attached bacteria are generally associated with other microorganisms, forming complex microbial consortia living in biofilms, microbial mats, and organic aggregates, or on other organisms as epibiotic communities. In all cases, bacteria largely dominate these consortia and are central to their formation, through their adhesive properties and their capacities to synthesize extracellular polymeric substances and to grow as entrapped colonies within these organic matrices. Attached bacteria are highly diverse, and in freshwaters mostly comprise uncultivated β-proteobacteria and members of Bacteroidetes. Some species harbor specialized appendages for attachment and others occupy particular microniches within their habitats. The controlling factors for attached bacteria are only partially known, primarily from the availability of substrates (i.e., the productivity of the milieu) and the activity of raptorial grazers, mainly protists. Attached bacteria respire and recycle organic matter into important nutrients and CO2 at high rates in biofilms and enhance planktonic rates, where suspended organic aggregates are well known microhabitats and hot spots of elevated microbial activity. Habitats for attached bacteria in aquatic ecosystems may provide protection from harmful conditions such as desiccation, pollutants, and UV solar radiation.
Published: 2009
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32. Communities structure of the planktonic halophiles in the solar saltern of Sfax, Tunisia

Author: Jannet Elloumi, Abderrahmen Bouain, Télesphore Sime-Ngando, Habib Ayadi, Jean-François Carrias, Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)-Université d'Auvergne - Clermont-Ferrand I (UdA), UR Biodiversité & Ecosystèmes Aquatiques, Université de Sfax - University of Sfax, Laboratoire Chrono-environnement - CNRS - UBFC (UMR 6249) (LCE), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Laboratoire Microorganismes : Génome et Environnement ( LMGE ), Université Blaise Pascal - Clermont-Ferrand 2 ( UBP ) -Centre National de la Recherche Scientifique ( CNRS ) -Université d'Auvergne - Clermont-Ferrand I ( UdA ), University of Sfax, Laboratoire Chrono-environnement ( LCE ), Université Bourgogne Franche-Comté ( UBFC ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Franche-Comté ( UFC ), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université d'Auvergne - Clermont-Ferrand I (UdA)-Centre National de la Recherche Scientifique (CNRS), and Laboratoire Chrono-environnement (UMR 6249) (LCE)
Subjects: 0106 biological sciences, Tunisia, Aquatic Science, Biology, Oceanography, 01 natural sciences, Algal bloom, Zooplankton, salinity gradient, 03 medical and health sciences, Botany, Phytoplankton, 14. Life underwater, Picoplankton, 030304 developmental biology, 0303 health sciences, [ SDE.BE ] Environmental Sciences/Biodiversity and Ecology, Ecology, 010604 marine biology & hydrobiology, plankton, Plankton, biology.organism_classification, Halophile, Salinity, 13. Climate action, solar salt work, Artemia salina, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, halophile
Abstract: International audience; The composition and distribution of the main planktonic halophilic micro-organisms (heterotrophic and autotrophic picoplankton, nanoplankton, phytoplankton, ciliates) and metazooplankton were investigated in six ponds of increasing salinity in the solar salt works of Sfax, Tunisia, from January to December 2003. Marked changes in the composition and biomass of the communities were found along the salinity gradient, especially at salinities of 150 and 350. Autotrophic picoplankton, nanoplankton, diatoms, dinoflagellates and ciliates characterized the less salted ponds. Planktonic biomass was the highest at intermediate salinity as a consequence of a bloom of Ochromonas. Species richness of phytoplankton, ciliates and zooplankton greatly decrease above a salinity of 150 and typical halophiles (Dunaliella salina, cyanobacteria, Fabrea salina and Artemia salina) were found between 150 and 350 salinity. In this environment, F. salina appeared more adapted than the brine shrimp to survive during phytoplankton blooms. The halophilic plankton was however almost entirely composed of heterotrophic prokaryotes in the crystallizers. We thus observed a progressive disappearance of the autotrophic planktonic communities along the salinity gradient. Multivariate analysis of the communities provides evidence that ponds represent discrete aquatic ecosystems within this salt works.
Published: 2009

33. Unveiling fungal zooflagellates as members of freshwater picoeukaryotes: evidence from a molecular diversity study in a deep meromictic lake

Author: Emilie Lefèvre, Jean-François Carrias, Christian Amblard, Eric Viscogliosi, Christophe Noël, Télesphore Sime-Ngando, Corinne Bardot, Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université d'Auvergne - Clermont-Ferrand I (UdA)-Centre National de la Recherche Scientifique (CNRS), Institute for Research on Environment and Sustainability, Newcastle University [Newcastle], Schistosomiase, paludisme et inflammation, Institut Pasteur de Lille, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lille, Droit et Santé, and Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)-Université d'Auvergne - Clermont-Ferrand I (UdA)
Subjects: 0106 biological sciences, Chlorophyll, Fresh Water, 010603 evolutionary biology, 01 natural sciences, Microbiology, Alveolate, DNA, Ribosomal, Polymerase Chain Reaction, 18S ribosomal RNA, 03 medical and health sciences, Phylogenetics, Phytoplankton, RNA, Ribosomal, 18S, Taxonomic rank, Flagellate, Ecology, Evolution, Behavior and Systematics, Ecosystem, Phylogeny, 030304 developmental biology, 0303 health sciences, Picoeukaryote, biology, Ecology, Chlorophyll A, Fungi, Temperature, biology.organism_classification, Plankton, Oxygen, France, Seasons, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Cercozoa
Abstract: International audience; This study presents an original 18S rRNA PCR survey of the freshwater picoeukaryote community, and was designed to detect unidentified heterotrophic picoflagellates (size range 0.6-5 microm) which are prevalent throughout the year within the heterotrophic flagellate assemblage in Lake Pavin. Four clone libraries were constructed from samples collected in two contrasting zones in the lake. Computerized statistic tools have suggested that sequence retrieval was representative of the in situ picoplankton diversity. The two sampling zones exhibited similar diversity patterns but shared only about 5% of the operational taxonomic units (OTUs). Phylogenetic analysis clustered our sequences into three taxonomic groups: Alveolates (30% of OTUs), Fungi (23%) and Cercozoa (19%). Fungi thus substantially contributed to the detected diversity, as was additionally supported by direct microscopic observations of fungal zoospores and sporangia. A large fraction of the sequences belonged to parasites, including Alveolate sequences affiliated to the genus Perkinsus known as zooparasites, and chytrids that include host-specific parasitic fungi of various freshwater phytoplankton species, primarily diatoms. Phylogenetic analysis revealed five novel clades that probably include typical freshwater environmental sequences. Overall, from the unsuspected fungal diversity unveiled, we think that fungal zooflagellates have been misidentified as phagotrophic nanoflagellates in previous studies. This is in agreement with a recent experimental demonstration that zoospore-producing fungi and parasitic activity may play an important role in aquatic food webs.
Published: 2007
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34. Zooplankton distribution in four ponds of different salinity: a seasonal study in the solar salterns of Sfax (Tunisia)

Author: Néji Toumi, Télesphore Sime-Ngando, Habib Ayadi, Mekki Boukhris, Jean-François Carrias, Olfa Abid, Abderrahmen Bouain, Carrias, Jean-François, UR Biodiversité & Ecosystèmes Aquatiques, Université de Sfax - University of Sfax, Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)-Université d'Auvergne - Clermont-Ferrand I (UdA), and Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université d'Auvergne - Clermont-Ferrand I (UdA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, Salinity, Tunisia, Arthropoda, Seasonal variation, Freshwater environment, Branchiopoda, Aquatic Science, 010603 evolutionary biology, 01 natural sciences, Zooplankton, Copepoda, Abundance (ecology), Crustacea, 14. Life underwater, Invertebrata, Detritus, biology, Ecology, 010604 marine biology & hydrobiology, fungi, Pond, Aquatic environment, Plankton, biology.organism_classification, Crustacean, Environmental factor, [SDE.BE] Environmental Sciences/Biodiversity and Ecology, Africa, Hydrobiology, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Artemia
Abstract: International audience; The seasonal distribution of metazooplankton and large-sized ciliates was studied in four ponds of different salinity in the solar salterns of Sfax (Tunisia). Total zooplankton abundance varied from 1 × 103 to 4.7 x 106 ind m-3. Salinity had a negative effect on the abundance of copepods and rotifers which were absent in the pond with the highest salt concentration (180‰) in which the number of taxa was low and Artemia or the ciliate Fabrea largely dominated the zooplankton community. Temperature and the presence of Dunaliella salina as prey appeared as key factors in controlling the abundance of Artemia, while organic detritus appeared as important in the diet of Fabrea. Change in zooplankton species composition along the hypersaline gradient (40-90‰) was primarily related to salinity. However, our data suggest the importance of both the abundance and composition of food in the spatial and temporal variations of some zooplankton species.
Published: 2005

35. Distribution, size, and bacterial colonization of pico- and nano-detrital organic particles (DOP) in two lakes of different trophic status

Author: Christian Amblard, Télesphore Sime-Ngando, Jean-Philippe Serre, Jean-François Carrias, Carrias, Jean-François, Laboratoire Microorganismes : Génome et Environnement (LMGE), and Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université d'Auvergne - Clermont-Ferrand I (UdA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, Chlorophyll a, 010504 meteorology & atmospheric sciences, Freshwater environment, Particle (ecology), Aquatic Science, Biology, Oceanography, 01 natural sciences, Auvergne, chemistry.chemical_compound, Size, Abundance (ecology), Quantitative analysis, 0105 earth and related environmental sciences, Trophic level, Particulate matters, Bacteria, Ecology, 010604 marine biology & hydrobiology, Depth, Lacustrine environment, Vertical distribution, biology.organism_classification, Substrate (marine biology), 6. Clean water, Europe, [SDE.BE] Environmental Sciences/Biodiversity and Ecology, chemistry, Environmental chemistry, Composition (visual arts), Organic matter, France, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Eutrophication
Abstract: International audience; Abundance, size spectra, and bacterial colonization of three types of freshwater pico- and nano-detrital organic particles (DOP), namely transparent exopolymeric particles (TEP), Coomassie-stained proteinaceous particles (CSP), and 4',6-diamidino-2-phenylindole (DAPI) yellow particles (DYP), were examined by epifluorescence microscope equipped with a color camera and a video recorder. The study was conducted during spring in the oligomesotrophic Lake Pavin and the eutrophic Lake Aydat, France. Pico- and nano-DOP were abundant (105-108 particles L-1) and exhibited significant variations in morphometric characteristics and numerical density within and among lakes, which is consistent with comparable studies known mostly from marine systems. Surface area and abundance of pico- and nano-DYP and nanoTEP were significantly higher in Lake Aydat than in Lake Pavin. Both these variables significantly increased with chlorophyll a concentration and the abundance of total heterotrophic bacteria. Bacterial colonization of DOP was highly related to the nature of the particle. Attached bacterial counts were on the order of 107-108 bacteria L-1, representing 1-17% of the total bacterial counts. Overall, we conclude that nonliving particulate organic matter are ubiquitous and abundantly occurring components in lakes where, at least, they serve as support for the attachment and as substrate for the metabolism of bacteria, the latter role being likely dependent on the composition of the particles and the trophic status of the milieu.
Published: 2002

36. Viral lysis, flagellate grazing potential, and bacterial production in Lake Pavin

Author: Yvan Bettarel, Jean-François Carrias, P. Lavandier, Denis Sargos, Christian Amblard, Frédéric Garabetian, Télesphore Sime-Ngando, Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université d'Auvergne - Clermont-Ferrand I (UdA)-Centre National de la Recherche Scientifique (CNRS), Centre d'Ecologie des Systèmes Aquatiques Continentaux (CESAC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)-Université d'Auvergne - Clermont-Ferrand I (UdA), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, Pigments, Lysis, Biotope, Heterotroph, Freshwater environment, Soil Science, Predation, Cell Count, Fresh Water, Biology, 01 natural sciences, Microbiology, 03 medical and health sciences, Microbial ecology, Epilimnion, Short term, Transmission, Animals, Flagellate, Mortality, Ecology, Evolution, Behavior and Systematics, Ecosystem, 0303 health sciences, Ecology, Bacteria, 030306 microbiology, 010604 marine biology & hydrobiology, Altitude, Eukaryota, biology.organism_classification, Europe, Infected cell, Ecological abundance, Lakes, Microscopy, Electron, Viruses, Loss, France, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Water Microbiology, Clearance rate, Microbial loop
Abstract: International audience; Abundances of different compartments of the microbial loop (i.e., viruses, heterotrophic bacteria, nonpigmented nanoflagellates, and pigmented nanoflagellates), bacterial heterotrophic production (BHP), viral lysis, and potential flagellate grazing impacts on the bacterial assemblages were estimated during a short-term study (24 h) conducted in June 1998 in the epilimnion (5 m) and metalimnion (10 m) of a moderate-altitude oligomesotrophic lake (Lake Pavin, France). Viral and bacterial abundances were higher in the metalimnion than in the epilimnion, whereas pigmented and nonpigmented nanoflagellates were more numerous in the epilimnion. The control of the BHP due to viral lysis (determined by examination of viral-containing bacteria using a transmission electron microscope) was significantly higher in the meta- (range = 6.0-33.7%, mean = 15.6%) than in the epilimnion (3.5-10.3%, 6.4%). The same was for the losses of BHP from the potential predation by nanoflagellates which ranged from 0.5 to 115.4% (mean = 38.7%) in the epilimnion, and from 0.7 to 97.5% (mean = 66.7%) in the metalimnion. Finally, estimated viral mediated mortality rates from the percentage of visibly infected cells and potential nanoflagellate grazing rates based on assumed clearance rates suggest that flagellates consumed a larger proportion of bacterial production than was lost to viral lysis.
Published: 2001

37. Dynamics and growth estimates of planktonic protists during early spring in Lake Pavin, France

Author: Télesphore Sime-Ngando, Antoine Thouvenot, Jean-François Carrias, Christian Amblard, Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université d'Auvergne - Clermont-Ferrand I (UdA)-Centre National de la Recherche Scientifique (CNRS), and Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)-Université d'Auvergne - Clermont-Ferrand I (UdA)
Subjects: 0106 biological sciences, 010504 meteorology & atmospheric sciences, Aquatic Science, Biology, medicine.disease_cause, 01 natural sciences, Algal bloom, Flagellates, Growth rates, medicine, 14. Life underwater, Gymnodinium, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences, Trophic level, Ciliate, Freshwaters, Ciliates, Ecology, 010604 marine biology & hydrobiology, Dinoflagellate, Protist, Pelagic zone, Protists, Plankton, biology.organism_classification, Lakes, [SDE.BE]Environmental Sciences/Biodiversity and Ecology
Abstract: International audience; The in situ growth rates of the dominant planktonic protists were estimated in Lake Pavin during early spring, from unfiltered (UF, i.e. raw) and fractionated (
Published: 2001
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38. Protistan Bacterivory in an Oligomesotrophic Lake: Importance of Attached Ciliates and Flagellates

Author: Gilles Bourdier, Christian Amblard, and Jean-François Carrias
Subjects: Bacterivore, Ecology, biology, Soil Science, biology.organism_classification, Zooplankton, Diatom, Algae, parasitic diseases, Phytoplankton, Protozoa, Photic zone, Flagellate, Ecology, Evolution, Behavior and Systematics
Abstract: Seasonal and depth variations of the abundance, biomass, and bacterivory of protozoa (heterotrophic and mixotrophic flagellates and ciliates) were determined during thermal stratification in an oligomesotrophic lake (Lake Pavin, France). Maximal densities of heterotrophic flagellates (1.9x10(3) cells ml-1) and ciliates (6.1 cells ml-1) were found in the metalimnion. Pigmented flagellates dominated the flagellate biomass in the euphotic zone. Community composition of ciliated protists varied greatly with depth, and both the abundance and biomass of ciliates was dominated by oligotrichs. Heterotrophic flagellates dominated grazing, accounting for 84% of total protistan bacterivory. Maximal grazing impact of heterotrophic flagellates was 18.9x10(6) bacteria 1(-1)h-1. On average, 62% of nonpigmented flagellates were found to ingest particles. Ciliates and mixotrophic flagellates averaged 13% and 3% of protistan bacterivory, respectively. Attached protozoa (ciliates and flagellates) were found to colonize the diatom Asterionella formosa. Attached bacterivores had higher ingestion rates than free bacterivorous protozoa and may account for 66% of total protozoa bacterivory. Our results indicated that even in low numbers, epibiotic protozoa may have a major grazing impact on free bacteria.
Published: 1996

39. The microbial loop in a humic lake: seasonal and vertical variations in the structure of the different communities

Author: Nadine Maurin, Jean-François Carrias, Gilles Bourdier, and Christian Amblard
Subjects: Cyanobacteria, Detritus, Water column, Algae, biology, Ecology, Dissolved organic carbon, Autotroph, Plankton, biology.organism_classification, Microbial loop
Abstract: Seasonal and vertical variations of the main microbial communities (heterotrophic bacteria, autotrophic picoplank- ton, auto- and heterotrophic nanoflagellates, ciliated protozoa and microalgae) and auto- and heterotrophic activities were estimated in a brown-colored humic and moderately acid lake in central France, the lake of Vassiviere. The results demonstrated the dominant role of light in the vertical distribution of autotrophic and mixotrophic microor- ganisms which are confined to the 0–5 m layer during thermal stratification. The bacterial biomass was high throughout the water column probably because of the great availability of dissolved organic matter. Consequently, the predatory microzooplankton and particularly the various trophic groups of ciliated protozoa, were distributed in the water column according to the vertical distribution of the particular food resources (detritus, bacteria, algae). However, despite the great abundance of algae and bacteria, biomass of flagellated and ciliated protozoa was relatively weak. Most of the phytoplanktonic biomass was filamentous (Diatoms) or colonial (Cyanobacteria) and therefore almost probably difficult to ingest for algivorous microzooplankton. Regarding the low abundance of bacterivorous protozoa, the relation with the special physicochemical properties of this lake is discussed.
Published: 1995
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40. Seasonal dynamics and vertical distribution of planktonic ciliates and their relationship to microbial food resources in the oligomesotrophic Lake Pavin

Author: Christian Amblard, Jean-François Carrias, and Gilles Bourdier
Subjects: Ciliate, Ecology, biology, Aquatic Science, Plankton, biology.organism_classification, Zooplankton, Algae, Phytoplankton, Photic zone, Hypolimnion, Picoplankton, Ecology, Evolution, Behavior and Systematics
Abstract: The planktonic ciliated protozoa and their potential prey (bacteria, autotrophic picoplankton, flagellates, algae) in Lake Pavin (Massif central of France) were investigated during the period of April to December, 1992. Ciliate abundance varied from 300 to 24,200 cells/l. Peak densities were observed during mixis for all sampling depths and in May-June in the cold aerobic hypolimnion. During the rest of the year, the species composition varied greatly with depth and season. Small algivorous prostomatids and large mixotrophic oligotrichs were most abundant in the euphotic zone during summer. Small filter-feeders were present at each depth throughout the study whereas haptorids and large size taxa were restricted to 15 m depth during spring and autumn. The highest density of ciliates occurred in the deep (40 m) cold aerobic hypolimnion due to the major spring development of the scuticociliate Uronema nigricans. This species seems to be adapted to cold and dilute freshwater habitats. Evidence for a major impact of availability and diversity of appropriate food in determining ciliate composition at different seasons and depths are given.

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