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Auteur Barnagaud, J.-Y.; Kissling, W.D.; Tsirogiannis, C.; Fisikopoulos, V.; Villeger, S.; Sekercioglu, C.H.; Svenning, J.-C.
Titre Biogeographical, environmental and anthropogenic determinants of global patterns in bird taxonomic and trait turnover Type Article scientifique
Année 2017 Publication Revue Abrégée Glob. Ecol. Biogeogr.
Volume 26 Numéro 10 Pages 1190-1200
Mots-Clés Anthropocene; Beta diversity; Beta-diversity; biogeographical legacies; biotic homogenization; climate changes; community; components; dispersal; functional diversity; functional diversity; life-history traits; mammal assemblages; net primary production; regional assemblages; specialization; species richness
Résumé AimTo assess contemporary and historical determinants of taxonomic and ecological trait turnover in birds worldwide. We tested whether taxonomic and trait turnover (1) are structured by regional bioclimatic conditions, (2) increase in relationship with topographic heterogeneity and environmental turnover and change according to current and historical environmental conditions, and (3) decrease with human impact. Major TaxaBirds. LocationGlobal. MethodsWe used computationally efficient algorithms to map the taxonomic and trait turnover of 8,040 terrestrial bird assemblages worldwide, based on a grid with 110km x 110 km resolution overlaid on the extent-of-occurrence maps of 7,964 bird species, and nine ecological traits reflecting six key aspects of bird ecology (diet, habitat use, thermal preference, migration, dispersal and body size). We used quantile regression and model selection to quantify the influence of biomes, environment (temperature, precipitation, altitudinal range, net primary productivity, Quaternary temperature and precipitation change) and human impact (human influence index) on bird turnover. ResultsBird taxonomic and trait turnover were highest in the north African deserts and boreal biomes. In the tropics, taxonomic turnover tended to be higher, but trait turnover was lower than in other biomes. Taxonomic and trait turnover exhibited markedly different or even opposing relationships with climatic and topographic gradients, but at their upper quantiles both types of turnover decreased with increasing human influence. Main conclusionsThe influence of regional, environmental and anthropogenic factors differ between bird taxonomic and trait turnover, consistent with an imprint of niche conservatism, environmental filtering and topographic barriers on bird regional assemblages. Human influence on these patterns is pervasive and demonstrates global biotic homogenization at a macroecological scale.
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ISSN 1466-822x ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2212
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Auteur Dias, M.S.; Oberdorff, T.; Hugueny, B.; Leprieur, F.; Jezequel, C.; Cornu, J.F.; Brosse, S.; Grenouillet, G.; Tedesco, P.A.
Titre Global imprint of historical connectivity on freshwater fish biodiversity Type Article scientifique
Année 2014 Publication Revue Abrégée Ecology Letters
Volume 17 Numéro 9 Pages 1130-1140
Mots-Clés Alpha diversity; Beta diversity; Biogeography; Quaternary climate changes; africa; climate changes; contemporary; diversity patterns; endemism; evolution; freshwater fish; global; history; north-america; richness; river systems; scale; sea-level changes; species turnover; species-richness
Résumé The relative importance of contemporary and historical processes is central for understanding biodiversity patterns. While several studies show that past conditions can partly explain the current biodiversity patterns, the role of history remains elusive. We reconstructed palaeo-drainage basins under lower sea level conditions (Last Glacial Maximum) to test whether the historical connectivity between basins left an imprint on the global patterns of freshwater fish biodiversity. After controlling for contemporary and past environmental conditions, we found that palaeo-connected basins displayed greater species richness but lower levels of endemism and beta diversity than did palaeo-disconnected basins. Palaeo-connected basins exhibited shallower distance decay of compositional similarity, suggesting that palaeo-river connections favoured the exchange of fish species. Finally, we found that a longer period of palaeo-connection resulted in lower levels of beta diversity. These findings reveal the first unambiguous results of the role played by history in explaining the global contemporary patterns of biodiversity.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 1461-023x ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 631
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Auteur Duffy, L.M.; Kuhnert, P.; Pethybridge, H.R.; Young, J.W.; Olson, R.J.; Logan, J.M.; Goñi, N.; Romanov, E.; Allain, V.; Staudinger, M.; Abecassis, M.; Choy, C.A.; Hobday, A.J.; Simier, M.; Galván-Magaña, F.; Potier, M.; Ménard, F.
Titre Global trophic ecology of yellowfin, bigeye, and albacore tunas: understanding predation on micronekton communities at ocean-basin scales Type Article scientifique
Année 2017 Publication Revue Abrégée Deep Sea Research Part II: Topical Studies in Oceanography
Volume 140 Numéro Pages 55-73
Mots-Clés classification trees; climate changes; ecosystems; food webs; inter-ocean comparison; macroecology; Meta-analysis; trophic relationships
Résumé Predator-prey interactions for three commercially valuable tuna species: yellowfin (Thunnus albacares), bigeye (T. obesus), and albacore (T. alalunga), collected over a 40-year period from the Pacific, Indian, and Atlantic Oceans, were used to quantitatively assess broad, macro-scale trophic patterns in pelagic ecosystems. Analysis of over 14,000 tuna stomachs, using a modified classification tree approach, revealed for the first time the global expanse of pelagic predatory fish diet and global patterns of micronekton diversity. Ommastrephid squids were consistently one of the top prey groups by weight across all tuna species and in most ocean bodies. Interspecific differences in prey were apparent, with epipelagic scombrid and mesopelagic paralepidid fishes globally important for yellowfin and bigeye tunas, respectively, while vertically-migrating euphausiid crustaceans were important for albacore tuna in the Atlantic and Pacific Oceans. Diet diversity showed global and regional patterns among tuna species. In the central and western Pacific Ocean, characterized by low productivity, a high diversity of micronekton prey was consumed while low prey diversity was evident in highly productive coastal waters where upwelling occurs. Spatial patterns of diet diversity were most variable in yellowfin and bigeye tunas while a latitudinal diversity gradient was observed with lower diversity in temperate regions for albacore tuna. Sea-surface temperature was a reasonable predictor of the diets of yellowfin and bigeye tunas, whereas chlorophyll-a was the best environmental predictor of albacore diet. These results suggest that the ongoing expansion of warmer, less productive waters in the world’s oceans may alter foraging opportunities for tunas due to regional changes in prey abundances and compositions.
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ISSN 0967-0645 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2102
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