0000000000563630

AUTHOR

David Velázquez

0000-0002-4127-8370

showing 6 related works from this author

Vertical structure of bi-layered microbial mats from Byers Peninsula, Maritime Antarctica

2013

AbstractA summer study of the vertical structure of bi-layered microbial mats was carried out on Byers Peninsula (Livingston Island, South Shetland Islands). These benthic communities had a common basic structure that consisted of two distinct layers differing in composition, morphology and colour. Our sampling focused on mats showing more layering, which thrived over moist soils and at the bottom of ponds. The photosynthetic pigments analysis performed by high-performance liquid chromatography demonstrated a major occurrence of cyanobacteria and diatoms on these mats, the former being more abundant in relative terms on the surface and composed by morphospecies grouping into orders Oscillat…

NostocalesBiomass (ecology)Chlorophyll aGeologyScytoneminBiologyOceanographybiology.organism_classificationchemistry.chemical_compoundchemistryBenthic zoneBotanyOscillatorialesMicrobial matChroococcalesEcology Evolution Behavior and SystematicsAntarctic Science
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Bacterioplankton Community Composition Along Environmental Gradients in Lakes From Byers Peninsula (Maritime Antarctica) as Determined by Next-Genera…

2019

This study comprises the first attempt to describe the planktonic bacterial communities of lakes from Byers Peninsula, one of the most significant limnological districts in the Maritime Antarctica, leveraging next-generation sequencing (NGS) technologies. For the survey, we selected 7 lakes covering the environmental gradient from inland to coastal lakes, some of them sampled both in surface and deep waters. Analysis provided just over 85,000 high quality sequences that were clustered into 864 unique Zero-radius Operational Taxonomic Units (ZOTUs) (i.e., 100% sequence similarity). Yet, several taxonomic uncertainties remained in the analysis likely suggesting the occurrence of local bacteri…

Microbiology (medical)lcsh:QR1-502Microbiologylcsh:Microbiology03 medical and health sciencesGammaproteobacteriaDominance (ecology)environmental gradientsByers PeninsulaOriginal Research030304 developmental biologyEnvironmental gradient0303 health sciencesbiology030306 microbiologyEcologybacterioplanktonBacteroidetesBacterioplanktonbiology.organism_classificationGeographyBenthic zonenext-generation sequencingOrdinationProteobacteriaMaritime Antarctic lakesFrontiers in Microbiology
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Byers Peninsula: A reference site for coastal, terrestrial and limnetic ecosystem studies in maritime Antarctica

2009

Abstract This article describes the development of an international and multidisciplinary project funded by the Spanish Polar Programme on Byers Peninsula (Livingston Island, South Shetlands). The project adopted Byers Peninsula as an international reference site for coastal and terrestrial (including inland waters) research within the framework of the International Polar Year initiative. Over 30 scientists from 12 countries and 26 institutions participated in the field work, and many others participated in the processing of the samples. The main themes investigated were: Holocene changes in climate, using both lacustrine sediment cores and palaeo-nests of penguins; limnology of the lakes, …

geographygeography.geographical_feature_categoryEcologyEcologyAquatic ecosystemLimnologyLimnopolarBiodiversityByers peninsulaEarth and Planetary Sciences(all)BiotaWetlandAquatic ScienceTerrestrial ecosystemsLakesOceanographyPeninsulaBiocomplexityLimnologyGeneral Earth and Planetary SciencesEcosystemEcology Evolution Behavior and SystematicsPolar Science
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Carbon dynamics modelization and biological community sensitivity to temperature in an oligotrophic freshwater Antarctic lake

2016

Lake Limnopolar, located in one of the areas on Earth experiencing the strongest local warming, has been studied as a maritime Antarctic lake model by the Limnopolar Research Team during the last decade. Data collected during this period revealed the existence of an important meteorological interannual variability in the area of Byers Peninsula. With the aim of increasing the knowledge of this ecosystem and its sensibility to climate change as a model ecosystem, as well as to calibrate the extent of the interannual variability, a carbon flow model was developed partly describing its microbial food web. This preliminary model aims to describe part of the carbon dynamics, especially for bacte…

0106 biological scienceschemistry.chemical_classificationMicrobial food web010504 meteorology & atmospheric sciencesEcology010604 marine biology & hydrobiologyEcological ModelingClimate changeBacterioplanktonForcing (mathematics)Plankton01 natural sciencesOceanographychemistryAbundance (ecology)Environmental scienceOrganic matterEcosystem0105 earth and related environmental sciencesEcological Modelling
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Maritime antarctic lakes as sentinels of climate change

2012

Remote lakes, such as lakes from the Maritime Antarctica, can be used as sentinels of climate change, because they are mostly free of direct anthropogenic pressures, and they experience climate change as a main stressor capable of modifying the ecosystem structure and function. In this paper, the content of a lecture that has been presented at the First Conference of Lake Sustainability, which has been centred in our studies on lakes from Byers Peninsula (Maritime Antarctica), are summarized. These included physical, chemical and biological studies of these lakes and other freshwater ecosystems, which highlighted the relevance of biotic interactions for these ecosystems and its sensibility …

geographygeography.geographical_feature_categoryEcologyGlobal warmingEcosystem modellingRegional warmingGeneral EngineeringClimate changeFreshwater ecosystemInvasive speciesPeninsulaSustainabilityClimate changeEnvironmental scienceEcosystemSpecies interactionsBiological invasionsGeneral Agricultural and Biological SciencesRegional warmingGeneral Environmental ScienceInternational Journal of Design & Nature and Ecodynamics
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High Diversity of the Viral Community from an Antarctic Lake

2009

Viruses are the most abundant biological entities and can control microbial communities, but their identity in terrestrial and freshwater Antarctic ecosystems is unknown. The genetic structure of an Antarctic lake viral community revealed unexpected genetic richness distributed across the highest number of viral families that have been found to date in aquatic viral metagenomes. In contrast to other known aquatic viromes, which are dominated by bacteriophage sequences, this Antarctic virus assemblage had a large proportion of sequences related to eukaryotic viruses, including phycodnaviruses and single-stranded DNA (ssDNA) viruses not previously identified in aquatic environments. We also o…

Genes ViralvirusesMolecular Sequence DataBiodiversityAntarctic RegionsDNA Single-StrandedFresh WaterGenome ViralBiologyVirus ReplicationFreezingAnimalsIce CoverEcosystemEcosystemMultidisciplinaryEcologyAquatic ecosystemDNA VirusesGenetic VariationBiodiversityCold ClimateMicrobial population biologyViral replicationMetagenomicsDNA ViralVirusesGenetic structureMetagenomeSeasonsSpecies richnessDNA CircularVirus Physiological PhenomenaScience
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