|   | 
Détails
   web
Enregistrements
Auteur Brouwer, G.M.; Duijnstee, I. a. P.; Hazeleger, J.H.; Rossi, F.; Lourens, L.J.; Middelburg, J.J.; Wolthers, M.
Titre Diet shifts and population dynamics of estuarine foraminifera during ecosystem recovery after experimentally induced hypoxia crises Type Article scientifique
Année 2016 Publication Revue Abrégée Estuar. Coast. Shelf Sci.
Volume (down) 170 Numéro Pages 20-33
Mots-Clés Bacteria; Benthic foraminifera; C-13 label; communities; Diet shifts; differential response; diversity; Hypoxia; in-situ; Intertidal; Macrofauna; Meiofauna; microphytobenthos carbon; population dynamics; Sediment
Résumé This study shows foraminiferal dynamics after experimentally induced hypoxia within the wider context of ecosystem recovery. C-13-labeled bicarbonate and glucose were added to the sediments to examine foraminiferal diet shifts during ecosystem recovery and test-size measurements were used to deduce population dynamics. Hypoxia-treated and undisturbed patches were compared to distinguish natural (seasonal) fluctuations from hypoxia-induced responses. The effect of timing of disturbance and duration of recovery were investigated. The foraminiferal diets and population dynamics showed higher fluctuations in the recovering patches compared to the controls. The foraminiferal diet and population structure of Haynesina germanica and Ammonia beccarii responded differentially and generally inversely to progressive stages of ecosystem recovery. Tracer inferred diet estimates in April and June and the two distinctly visible cohorts in the test-size distribution, discussed to reflect reproduction in June, strongly suggest that the ample availability of diatoms during the first month of ecosystem recovery after the winter hypoxia was likely profitable to A. beccarii. Enhanced reproduction itself was strongly linked to the subsequent dietary shift to bacteria. The distribution of the test dimensions of H. germanica indicated that this species had less fluctuation in population structure during ecosystem recovery but possibly reproduced in response to the induced winter hypoxia. Bacteria seemed to consistently contribute more to the diet of H. germanica than diatoms. For the diet and test-size distribution of both species, the timing of disturbance seemed to have a higher impact than the duration of the subsequent recovery period. (C) 2016 Published by Elsevier Ltd.
Adresse
Auteur institutionnel Thèse
Editeur Lieu de Publication Éditeur
Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0272-7714 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ alain.herve @ collection 2065
Lien permanent pour cet enregistrement
 

 
Auteur McLean, M.; Mouillot, D.; Villeger, S.; Graham, N.A.J.; Auber, A.
Titre Interspecific differences in environmental response blur trait dynamics in classic statistical analyses Type Article scientifique
Année 2019 Publication Revue Abrégée Mar. Biol.
Volume (down) 166 Numéro 12 Pages 152
Mots-Clés climate-change; community composition; ecology; framework; functional diversity; impact; rules
Résumé Trait-based ecology strives to better understand how species, through their bio-ecological traits, respond to environmental changes, and influence ecosystem functioning. Identifying which traits are most responsive to environmental changes can provide insight for understanding community structuring and developing sustainable management practices. However, misinterpretations are possible, because standard statistical methods (e.g., principal component analysis and linear regression) for identifying and ranking the responses of different traits to environmental changes ignore interspecific differences. Here, using both artificial data and real-world examples from marine fish communities, we show how considering species-specific responses can lead to drastically different results than standard community-level methods. By demonstrating the potential impacts of interspecific differences on trait dynamics, we illuminate a major, yet rarely discussed issue, highlighting how analytical misinterpretations can confound our basic understanding of trait responses, which could have important consequences for biodiversity conservation.
Adresse
Auteur institutionnel Thèse
Editeur Lieu de Publication Éditeur
Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0025-3162 ISBN Médium
Région Expédition Conférence
Notes WOS:000496131000001 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2660
Lien permanent pour cet enregistrement
 

 
Auteur Dobrovolski, R.; Loyola, R.D.; Guilhaumon, F.; Gouveia, S.F.; Diniz, J.A.F.
Titre Global agricultural expansion and carnivore conservation biogeography Type Article scientifique
Année 2013 Publication Revue Abrégée Biol. Conserv.
Volume (down) 165 Numéro Pages 162-170
Mots-Clés Agriculture; Global biodiversity conservation priorities; Image; Mammal; Spatial prioritization; Zonation; biodiversity; biodiversity conservation; conservation; conserving; extinction risk; hotspots; human-population density; integrating economic costs; land-use; mammal conservation; prioritization schemes; protected areas
Résumé Global conservation prioritization must address conflicting land uses. We tested for spatial congruence between agricultural expansion in the 21st century and priority areas for carnivore conservation worldwide. We evaluated how including agricultural expansion data in conservation planning reduces such congruence and estimated the consequences of such an approach for the performance of resulting priority area networks. We investigated the correlation between projections of agricultural expansion and the solutions of global spatial prioritizations for carnivore conservation through the implementation of different goals: (1) purely maximizing species representation and (2) representing species while avoiding sites under high pressure for agriculture expansion. We also evaluated the performance of conservation solutions based on species' representation and their spatial congruence with established global prioritization schemes. Priority areas for carnivore conservation were spatially correlated with future agricultural distribution and were more similar to global conservation schemes with high vulnerability. Incorporating future agricultural expansion in the site selection process substantially reduced spatial correlation with agriculture, resulting in a spatial solution more similar to global conservation schemes with low vulnerability. Accounting for agricultural expansion resulted in a lower representation of species, as the average proportion of the range represented reduced from 58% to 32%. We propose that priorities for carnivore conservation could be integrated into a strategy that concentrates different conservation actions towards areas where they are likely to be more effective regarding agricultural expansion. (C) 2013 Elsevier Ltd. All rights reserved.
Adresse
Auteur institutionnel Thèse
Editeur Lieu de Publication Éditeur
Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0006-3207 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 622
Lien permanent pour cet enregistrement
 

 
Auteur Escalas, A.; Catherine, A.; Maloufi, S.; Cellamare, M.; Hamlaoui, S.; Yepremian, C.; Louvard, C.; Troussellier, M.; Bernard, C.
Titre Drivers and ecological consequences of dominance in periurban phytoplankton communities using networks approaches Type Article scientifique
Année 2019 Publication Revue Abrégée Water Res.
Volume (down) 163 Numéro Pages Unsp-114893
Mots-Clés blooms; climate-change; Co-occurrence network; Community cohesion; Community functioning; cooccurrence patterns; cyanobacteria dominance; diversity; Dominance; fresh-waters; lakes; light; Periurban waterbodies; Phytoplankton; resource use efficiency; species richness
Résumé Evaluating the causes and consequences of dominance by a limited number of taxa in phytoplankton communities is of huge importance in the current context of increasing anthropogenic pressures on natural ecosystems. This is of particular concern in densely populated urban areas where usages and impacts of human populations on water ecosystems are strongly interconnected. Microbial biodiversity is commonly used as a bioindicator of environmental quality and ecosystem functioning, but there are few studies at the regional scale that integrate the drivers of dominance in phytoplankton communities and their consequences on the structure and functioning of these communities. Here, we studied the causes and consequences of phytoplankton dominance in 50 environmentally contrasted waterbodies, sampled over four summer campaigns in the highly-populated Ile-de-France region (IDF). Phytoplankton dominance was observed in 32-52% of the communities and most cases were attributed to Chlorophyta (35.5-40.6% of cases) and Cyanobacteria (30.3-36.5%). The best predictors of dominance were identified using multinomial logistic regression and included waterbody features (surface, depth and connection to the hydrological network) and water column characteristics (total N, TN:TP ratio, water temperature and stratification). The consequences of dominance were dependent on the identity of the dominant organisms and included modifications of biological attributes (richness, cohesion) and functioning (biomass, RUE) of phytoplankton communities. We constructed co-occurrence networks using high resolution phytoplankton biomass and demonstrated that networks under dominance by Chlorophyta and Cyanobacteria exhibited significantly different structure compared with networks without dominance. Furthermore, dominance by Cyanobacteria was associated with more profound network modifications (e.g. cohesion, size, density, efficiency and proportion of negative links), suggesting a stronger disruption of the structure and functioning of phytoplankton communities in the conditions in which this group dominates. Finally, we provide a synthesis on the relationships between environmental drivers, dominance status, community attributes and network structure. (C) 2019 Elsevier Ltd. All rights reserved.
Adresse
Auteur institutionnel Thèse
Editeur Lieu de Publication Éditeur
Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0043-1354 ISBN Médium
Région Expédition Conférence
Notes WOS:000483006400038 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2636
Lien permanent pour cet enregistrement
 

 
Auteur Becheler, R.; Cassone, A.-L.; Noel, P.; Mouchel, O.; Morrison, C.L.; Arnaud-Haond, S.
Titre Low incidence of clonality in cold water corals revealed through the novel use of a standardized protocol adapted to deep sea sampling Type Article scientifique
Année 2017 Publication Revue Abrégée Deep-Sea Res. Part II-Top. Stud. Oceanogr.
Volume (down) 145 Numéro Pages 120-130
Mots-Clés diversity; dispersal; disturbance; Lophelia pertusa; Madrepora oculata; organisms; population-structure; asexual reproduction; Clonality; Cold-water coral; Fine-grained spatial genetic structure; gorgonian coral; lophelia-pertusa; pertusa linnaeus 1758; spatial genetic-structure; Standardized sampling
Résumé Sampling in the deep sea is a technical challenge, which has hindered the acquisition of robust datasets that are necessary to determine the fine-grained biological patterns and processes that may shape genetic diversity. Estimates of the extent of clonality in deep-sea species, despite the importance of clonality in shaping the local dynamics and evolutionary trajectories, have been largely obscured by such limitations. Cold-water coral reefs along European margins are formed mainly by two reef-building species, Lophelia pertusa and Madrepora oculata. Here we present a fine-grained analysis of the genotypic and genetic composition of reefs occurring in the Bay of Biscay, based on an innovative deep-sea sampling protocol. This strategy was designed to be standardized, random, and allowed the georeferencing of all sampled colonies. Clonal lineages discriminated through their Multi-Locus Genotypes (MLG) at 6-7 microsatellite markers could thus be mapped to assess the level of clonality and the spatial spread of clonal lineages. High values of clonal richness were observed for both species across all sites suggesting a limited occurrence of clonality, which likely originated through fragmentation. Additionally, spatial autocorrelation analysis underlined the possible occurrence of fine-grained genetic structure in several populations of both L. pertusa and M. oculata. The two cold-water coral species examined had contrasting patterns of connectivity among canyons, with among-canyon genetic structuring detected in M. oculata, whereas L. pertusa was panmictic at the canyon scale. This study exemplifies that a standardized, random and georeferenced sampling strategy, while challenging, can be applied in the deep sea, and associated benefits outlined here include improved estimates of fine grained patterns of clonality and dispersal that are comparable across sites and among species.
Adresse
Auteur institutionnel Thèse
Editeur Lieu de Publication Éditeur
Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0967-0645 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ alain.herve @ collection 2257
Lien permanent pour cet enregistrement