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Auteur Ramirez-Romero, E.; Molinero, J.C.; Sommer, U.; Salhi, N.; Yahia, O.K.-D.; Yahia, M.N.D.
Titre Phytoplankton size changes and diversity loss in the southwestern Mediterranean Sea in relation to long-term hydrographic variability Type Article scientifique
Année 2020 Publication Revue Abrégée Estuar. Coast. Shelf Sci.
Volume 235 Numéro (up) Pages 106574
Mots-Clés bay; climate-change; Diversity loss; dynamics; evolution; jellyfish; marine; Nanophytoplankton; Ocean warming; patterns; Phytoplankton diversity; plankton communities; Size structural changes; Southwestern mediterranean; temperature; time-series
Résumé Structural changes in plankton primary producers have large implications for food web dynamics, energy fluxes and the vertical export of biogenic particulate carbon. Here we examine phytoplankton data spanning the period 1993-2008 from the Bay of Tunis, southwestern Mediterranean Sea, in relation to long term hydroclimate variability. We show a conspicuous shift in the structure of the phytoplankton community characterized by an increase of small-sized species and diversity loss, revealing a dominance of smaller blooming diatoms and cyanobacteria. Such changes were concurrent with marked modifications in hydroclimatic patterns experienced in the Bay of Tunis consisting of a shift towards enhanced winter precipitation together with rising temperatures. This novel study shows an overall rise in the proportion of small phytoplankton cells and a decreasing trend in phytoplankton diversity in the southern Mediterranean area. These findings warn of a potential decline of trophic efficiency and lesser food web stability resulting from mean size reduction and the diversity loss.
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Volume de collection Numéro de collection Edition
ISSN 0272-7714 ISBN Médium
Région Expédition Conférence
Notes WOS:000527915700034 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2766
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Auteur Puerta, P.; Johnson, C.; Carreiro-Silva, M.; Henry, L.-A.; Kenchington, E.; Morato, T.; Kazanidis, G.; Luis Rueda, J.; Urra, J.; Ross, S.; Wei, C.-L.; Manuel Gonzalez-Irusta, J.; Arnaud-Haond, S.; Orejas, C.
Titre Influence of Water Masses on the Biodiversity and Biogeography of Deep-Sea Benthic Ecosystems in the North Atlantic Type Article scientifique
Année 2020 Publication Revue Abrégée Front. Mar. Sci.
Volume 7 Numéro (up) Pages 239
Mots-Clés antarctic intermediate water; biodiversity; biogeography; climate-change impacts; coral lophelia-pertusa; deep-sea; food-supply mechanisms; global habitat suitability; meridional overturning circulation; ne atlantic; North Atlantic; ocean acidification; porcupine seabight; rockall trough margin; vulnerable marine ecosystems; water masses
Résumé Circulation patterns in the North Atlantic Ocean have changed and re-organized multiple times over millions of years, influencing the biodiversity, distribution, and connectivity patterns of deep-sea species and ecosystems. In this study, we review the effects of the water mass properties (temperature, salinity, food supply, carbonate chemistry, and oxygen) on deep-sea benthic megafauna (from species to community level) and discussed in future scenarios of climate change. We focus on the key oceanic controls on deep-sea megafauna biodiversity and biogeography patterns. We place particular attention on cold-water corals and sponges, as these are ecosystem-engineering organisms that constitute vulnerable marine ecosystems (VME) with high associated biodiversity. Besides documenting the current state of the knowledge on this topic, a future scenario for water mass properties in the deep North Atlantic basin was predicted. The pace and severity of climate change in the deep-sea will vary across regions. However, predicted water mass properties showed that all regions in the North Atlantic will be exposed to multiple stressors by 2100, experiencing at least one critical change in water temperature (+2 degrees C), organic carbon fluxes (reduced up to 50%), ocean acidification (pH reduced up to 0.3), aragonite saturation horizon (shoaling above 1000 m) and/or reduction in dissolved oxygen (> 5%). The northernmost regions of the North Atlantic will suffer the greatest impacts. Warmer and more acidic oceans will drastically reduce the suitable habitat for ecosystem-engineers, with severe consequences such as declines in population densities, even compromising their long-term survival, loss of biodiversity and reduced biogeographic distribution that might compromise connectivity at large scales. These effects can be aggravated by reductions in carbon fluxes, particularly in areas where food availability is already limited. Declines in benthic biomass and biodiversity will diminish ecosystem services such as habitat provision, nutrient cycling, etc. This study shows that the deep-sea VME affected by contemporary anthropogenic impacts and with the ongoing climate change impacts are unlikely to withstand additional pressures from more intrusive human activities. This study serves also as a warning to protect these ecosystems through regulations and by tempering the ongoing socio-political drivers for increasing exploitation of marine resources.
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Notes WOS:000526864100001 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2767
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Auteur Fournier, T.; Fevre, J.; Carcaillet, F.; Carcaillet, C.
Titre For a few years more: reductions in plant diversity 70 years after the last fire in Mediterranean forests Type Article scientifique
Année 2020 Publication Revue Abrégée Plant Ecol.
Volume Numéro (up) Pages
Mots-Clés climate-change; community composition; Community diversity; disturbance; Disturbance; Ecology; establishment; Fire; Forest; land-use; pinus-halepensis; postfire regeneration; regeneration patterns; Richness; succession; Succession; vegetation dynamics
Résumé Changes in community diversity and dynamics after fires in Mediterranean ecosystems are rarely investigated more than a few years after the fire even though pronounced changes can be expected in the longer term due to substitution of canopy species. Pinus halepensis is strongly promoted by wildfire and should therefore be gradually substituted by Quercus species as the time since the last fire increases. We hypothesized that this tree substitution would cause changes in understorey plant diversity by changing resource availability and the abundance and properties of woody debris, leading to changes in biogeochemical processes. To test this hypothesis, we investigated the effect of the time since last fire on vascular plant composition and diversity by studying a 130 years post-fire chronosequence in mixed Mediterranean forests. The canopy composition went from domination by Pinus halepensis to domination by Quercus 70 years after the most recent fire. This transformation was associated with a change in the understorey involving a rarefaction of species present during the first decades after the fire. The plant density or cover also changed with time since the last fire, indicating a succession driven by species rarefaction rather than substitution. The mean richness and Shannon diversity per quadrat were highest shortly after the fire, and were significantly lower 70 or more years after the last fire. Fires are important for supporting highly diversified fire-dependent plant communities, and total plant richness decreases monotonically over time after fires, suggesting that fire suppression may reduce diversity in Mediterranean forests.
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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 1385-0237 ISBN Médium
Région Expédition Conférence
Notes WOS:000530957300001 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2793
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Auteur McLean, M.; Auber, A.; Graham, N.A.J.; Houk, P.; Villeger, S.; Violle, C.; Thuiller, W.; Wilson, S.K.; Mouillot, D.
Titre Trait structure and redundancy determine sensitivity to disturbance in marine fish communities Type Article scientifique
Année 2019 Publication Revue Abrégée Glob. Change Biol.
Volume 25 Numéro (up) 10 Pages 3424-3437
Mots-Clés biodiversity; climate change; climate-change; coral reefs; coral-reef fish; diversity stability; ecological traits; ecosystem functioning; ecosystem productivity; egg buoyancy; English Channel; functional diversity; functional redundancy; north-sea; regime shifts; response diversity; vulnerability
Résumé Trait diversity is believed to influence ecosystem dynamics through links between organismal traits and ecosystem processes. Theory predicts that key traits and high trait redundancy-large species richness and abundance supporting the same traits-can buffer communities against environmental disturbances. While experiments and data from simple ecological systems lend support, large-scale evidence from diverse, natural systems under major disturbance is lacking. Here, using long-term data from both temperate (English Channel) and tropical (Seychelles Islands) fishes, we show that sensitivity to disturbance depends on communities' initial trait structure and initial trait redundancy. In both ecosystems, we found that increasing dominance by climatically vulnerable traits (e.g., small, fast-growing pelagics/corallivores) rendered fish communities more sensitive to environmental change, while communities with higher trait redundancy were more resistant. To our knowledge, this is the first study demonstrating the influence of trait structure and redundancy on community sensitivity over large temporal and spatial scales in natural systems. Our results exemplify a consistent link between biological structure and community sensitivity that may be transferable across ecosystems and taxa and could help anticipate future disturbance impacts on biodiversity and ecosystem functioning.
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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 1354-1013 ISBN Médium
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Notes WOS:000486150200018 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2652
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Auteur Yates, K.L.; Bouchet, P.J.; Caley, M.J.; Mengersen, K.; Randin, C.F.; Parnell, S.; Fielding, A.H.; Bamford, A.J.; Ban, S.; Marcia Barbosa, A.; Dormann, C.F.; Elith, J.; Embling, C.B.; Ervin, G.N.; Fisher, R.; Gould, S.; Graf, R.F.; Gregr, E.J.; Halpin, P.N.; Heikkinen, R.K.; Heinanen, S.; Jones, A.R.; Krishnakumar, P.K.; Lauria, V.; Lozano-Montes, H.; Mannocci, L.; Mellin, C.; Mesgaran, M.B.; Moreno-Amat, E.; Mormede, S.; Novaczek, E.; Oppel, S.; Crespo, G.O.; Peterson, A.T.; Rapacciuolo, G.; Roberts, J.J.; Ross, R.E.; Scales, K.L.; Schoeman, D.; Snelgrove, P.; Sundblad, G.; Thuiller, W.; Torres, L.G.; Verbruggen, H.; Wang, L.; Wenger, S.; Whittingham, M.J.; Zharikov, Y.; Zurell, D.; Sequeira, A.M.M.
Titre Outstanding Challenges in the Transferability of Ecological Models Type Article scientifique
Année 2018 Publication Revue Abrégée Trends Ecol. Evol.
Volume 33 Numéro (up) 10 Pages 790-802
Mots-Clés abundance; biotic interactions; climate-change; decision-making; distributions; habitat selection; niche; predictive models; species distribution models; temporal transferability
Résumé Predictive models are central to many scientific disciplines and vital for informing management in a rapidly changing world. However, limited understanding of the accuracy and precision of models transferred to novel conditions (their 'transferability') undermines confidence in their predictions. Here, 50 experts identified priority knowledge gaps which, if filled, will most improve model transfers. These are summarized into six technical and six fundamental challenges, which underlie the combined need to intensify research on the determinants of ecological predictability, including species traits and data quality, and develop best practices for transferring models. Of high importance is the identification of a widely applicable set of transferability metrics, with appropriate tools to quantify the sources and impacts of prediction uncertainty under novel conditions.
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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 0169-5347 ISBN Médium
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Notes Approuvé pas de
Numéro d'Appel MARBEC @ alain.herve @ collection 2447
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