8 documents.
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Cermeño P., J.M. Benton, O. Paz, C, Vérard
Scientific Reports, 1, 15969, 1-9. DOI: 10.1038/s41598-017-16257-w (BibTeX: cermeno.etal.2017)
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Marañón E., W.M. Balch, P. Cermeño, N. González, C. Sobrino, A. Fernández, M. Huete-Ortega, D.C. López-Sandoval, M. Delgado, M. Estrada, M. Álvarez, E. Fernández-Guallart, C. Pelejero
Limnology and Oceanography, 61, 4, 1345-1357. DOI: 10.1002/lno.10295 (BibTeX: maranon.etal.2016)
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Cermeño P., P. Chouciño, B. Fernández-Castro, F.G. Figueiras, E. Marañón, C. Marrasé, B. Mouriño-Carballido, M. Pérez-Lorenzo, T. Rodríguez-Ramos, I.G. Teixeira, S.M. Vallina
Frontiers in Marine Science, 3, 173, 1-10. DOI: 10.3389/fmars.2016.00173 (BibTeX: cermeno.etal.2016)
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Pinedo-González P., A.J. West, A. Tovar-Sánchez, C.M. Duarte, E. Marañón, P. Cermeño, N. González, C. Sobrino, M. Huete-Ortega, A. Fernández, D.C. López-Sandoval, M. Vidal, D. Blasco, M. Estrada, S.A. Sañudo-Wilhelmy
Global Biogeochemical Cycles, 29, 10, 1763-1781. DOI: 10.1002/2015GB005149 (BibTeX: pinedogonzalez.etal.2015)
Resum: Veure
The distribution of bioactive trace metals has the potential to enhance or limit primary productivity and carbon export in some regions of the world ocean. To study these connections, the concentrations of Cd, Co, Cu, Fe, Mo, Ni, and V were determined for 110 surface water samples collected during the Malaspina 2010 Circumnavigation Expedition (MCE). Total dissolved Cd, Co, Cu, Fe, Mo, Ni, and V concentrations averaged 19.0 ± 5.4 pM, 21.4 ± 12 pM, 0.91 ± 0.4 nM, 0.66 ± 0.3 nM, 88.8 ± 12 nM, 1.72 ± 0.4 nM, and 23.4 ± 4.4 nM, respectively, with the lowest values detected in the Central Pacific and increased values at the extremes of all transects near coastal zones. Trace metal concentrations measured in surface waters of the Atlantic Ocean during the MCE were compared to previously published data for the same region. The comparison revealed little temporal changes in the distribution of Cd, Co, Cu, Fe, and Ni over the last 30 years. We utilized a multivariable linear regression model to describe potential relationships between primary productivity and the hydrological, biological, trace nutrient and macronutrient data collected during the MCE. Our statistical analysis shows that primary productivity in the Indian Ocean is best described by chlorophyll a, NO3, Ni, temperature, SiO4, and Cd. In the Atlantic Ocean, primary productivity is correlated with chlorophyll a, NO3, PO4, mixed layer depth, Co, Fe, Cd, Cu, V, and Mo. The variables salinity, temperature, SiO4, NO3, PO4, Fe, Cd, and V were found to best predict primary productivity in the Pacific Ocean. These results suggest that some of the lesser studied trace elements (e.g., Ni, V, Mo, and Cd) may play a more important role in regulating oceanic primary productivity than previously thought and point to the need for future experiments to verify their potential biological functions.
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Vallina S.M., M.J. Follows, S. Dutkiewicz, J.M. Montoya, P. Cermeno, M. Loreau
Nature, 5, 4299, 1-10. DOI: 10.1038/ncomms5299 (BibTeX: vallina.etal.2014a)
Resum: Veure
The shape of the productivity-diversity relationship (PDR) for marine phytoplankton has been suggested to be unimodal, that is, diversity peaking at intermediate levels of productivity. However, there are few observations and there has been little attempt to understand the mechanisms that would lead to such a shape for planktonic organisms. Here we use a marine ecosystem model together with the community assembly theory to explain the shape of the unimodal PDR we obtain at the global scale. The positive slope from low to intermediate productivity is due to grazer control with selective feeding, which leads to the predator-mediated coexistence of prey. The negative slope at high productivity is due to seasonal blooms of opportunist species that occur before they are regulated by grazers. The negative side is only unveiled when the temporal scale of the observation captures the transient dynamics, which are especially relevant at highly seasonal latitudes. Thus selective predation explains the positive side while transient competitive exclusion explains the negative side of the unimodal PDR curve. The phytoplankton community composition of the positive and negative sides is mostly dominated by slow-growing nutrient specialists and fast-growing nutrient opportunist species, respectively.
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Cermeño P., I.G. Teixeira, M. Branco, F.G. Figueiras, E. Marañón
Journal of Plankton Research, 36, 4, 1135-1139. DOI: 10.1093/plankt/fbu033 (BibTeX: cermeno.etal.2014b)
Resum: Veure
We examined large volumes of seawater under the microscope to explore the limits of phytoplankton diversity in a highly dynamic coastal ecosystem. Our analysis showed that conventional sample volumes severely underestimate the species rich- ness of these phytoplankton communities. The number of species observed doubled after a 10-fold increase in sample volume, implying that estimates of phytoplankton species richness depend critically on sampling effort. The volume of sample needed to detect 90% of the species varied between 0.25 and 1 L depending on the concen- tration of phytoplankton biomass.
Paraules clau: Phytoplankton, sample size, species-accumulation curve, diversity
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Cermeño P., E. Marañón, O.E. Romero
Journal of Plankton Research, 35, 1, 12-21. DOI: 10.1093/plankt/fbs073 (BibTeX: cermeno.etal.2013b)
Resum: Veure
The high temporal resolution of the marine microfossil record makes it possible to explore how microbial communities responded to abrupt climate changes in the past. We analysed changes in species richness and total abundance of marine diatoms in sedimentary records from the Mauritanian upwelling system and the Panama Basin spanning the last 100 000 years. The analysis shows instances of community change and recovery linked to episodes of rapid, sub-millennial scale climate change (e.g. Heinrich events). The probability of sampling a given species during the perturbation increased with the mean abundance of the species in the database, indicating that (i) dominant species were persistent through long periods of time and (ii) rare species, with low population densities, accounted for much of the variability in species richness. To the extent that contemporaneous climate change falls within the range of climate variability analysed here, our results point to important changes in the structure of marine diatom communities, yet these changes will be reversible. These results highlight the importance of integrating fossil data and ecological theories to understand the effect of climate change on the ecological and biogeochemical functioning of marine ecosystems.
Paraules clau: marine diatoms fossil record Late Quaternary abrupt climate change Heinrich events dispersal community stability
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Cermeño P., T. Rodríguez-Ramos, M. Dornelas, F.G. Figueiras, E. Marañón, I.G. Teixeira, S.M. Vallina
Marine Ecology Progress Series, 488, 1-9. DOI: 10.3354/meps10443 (BibTeX: cermeno.etal.2013c)
Resum: Veure
Microorganisms attain high population densities, which has led microplankton ecologists to assume that samples of a few tens of millilitres suffice to characterize the assemblage of species. However, the observation that microbial plankton communities contain a large pool of species with low population densities casts doubt on the validity of estimates based on conventional sampling methods. By standardizing estimates of species numbers, we show that marine phytoplankton communities have been undersampled more severely in ecosystems of low productivity, thus leading to bias in the patterns of diversity reported previously. We found that phytoplankton communities from unproductive, subtropical waters fit to right-skewed, lognormal species-abundance distributions, which has long been interpreted to arise from incomplete censuses. The sampling-standardized estimates of species richness show no relationship with ecosystem productivity, arguing against the idea that phytoplankton diversity peaks at intermediate levels of primary production. These results suggest that these 2 fundamental properties of marine phytoplankton communities, viz. diversity and productivity, might not be linked mechanistically.
Paraules clau: Diversity–productivity relationship · Rarefaction · Species abundance distribution · Undersampling