Distribution of diatoms and mollusks in shallow lakes from the semiarid Pampa region, Argentina: Their relative paleoenvironmental significance

The aim of this study was to assess the potential of diatoms and mollusks as paleoenvironmental indicators in semiarid lakes of the Argentinean Pampas. At each lake, physical and chemical variables were quantified, and diatoms and mollusks collected. The relationships between environmental variables...

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Detalles Bibliográficos
Publicado: 2012
Materias:
Conductivity
Hardness
Ordination techniques
Paleoenvironmental bioindicators
South American Arid Diagonal
bioindicator
conductivity
diatom
lake ecosystem
mollusc
ordination
paleoenvironment
qualitative analysis
Quaternary
semiarid region
shallow water
Argentina
Pampas
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01401963_v78_n_p65_Hassan
http://hdl.handle.net/20.500.12110/paper_01401963_v78_n_p65_Hassan
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_01401963_v78_n_p65_Hassan
record_format dspace
spelling paper:paper_01401963_v78_n_p65_Hassan2023-06-08T15:11:05Z Distribution of diatoms and mollusks in shallow lakes from the semiarid Pampa region, Argentina: Their relative paleoenvironmental significance Conductivity Hardness Ordination techniques Paleoenvironmental bioindicators South American Arid Diagonal bioindicator conductivity diatom lake ecosystem mollusc ordination paleoenvironment qualitative analysis Quaternary semiarid region shallow water Argentina Pampas The aim of this study was to assess the potential of diatoms and mollusks as paleoenvironmental indicators in semiarid lakes of the Argentinean Pampas. At each lake, physical and chemical variables were quantified, and diatoms and mollusks collected. The relationships between environmental variables and biological assemblages were explored through ordination techniques. Lakes were highly alkaline (pH 9.5-10.5), and varied significantly in conductivity (0.2-15.7mS/cm) and hardness (120-1874mg/l CaCO 3). A total of 79 diatom and two mollusk species were identified. The highest percentage variance in diatom data was explained by hardness, conductivity, and mud percentage. Mollusk variability was significantly related to conductivity, hardness, and vegetation cover. Diatom-based ordination of sites accurately reflected the main environmental gradients characteristic of the region, while the resolution provided by mollusk-based ordinations was lower, mainly as consequence of the wide ranges of tolerance to hardness and conductivity exhibited by the two species represented. Hence, while the use of mollusks as paleoenvironmental indicators is only valid at a large, regional scale, diatoms allow discriminating local conditions and subtle environmental differences. As a consequence, the results emphasize the use of mollusks as qualitative and semi-quantitative indicators, while the strong statistical relationship between diatoms and climate-driven environmental parameters highlights their potential use as quantitative indicators of Quaternary climatic changes in the semiarid Pampas. © 2011 Elsevier Ltd. 2012 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01401963_v78_n_p65_Hassan http://hdl.handle.net/20.500.12110/paper_01401963_v78_n_p65_Hassan
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Conductivity
Hardness
Ordination techniques
Paleoenvironmental bioindicators
South American Arid Diagonal
bioindicator
conductivity
diatom
lake ecosystem
mollusc
ordination
paleoenvironment
qualitative analysis
Quaternary
semiarid region
shallow water
Argentina
Pampas
spellingShingle Conductivity
Hardness
Ordination techniques
Paleoenvironmental bioindicators
South American Arid Diagonal
bioindicator
conductivity
diatom
lake ecosystem
mollusc
ordination
paleoenvironment
qualitative analysis
Quaternary
semiarid region
shallow water
Argentina
Pampas
Distribution of diatoms and mollusks in shallow lakes from the semiarid Pampa region, Argentina: Their relative paleoenvironmental significance
topic_facet Conductivity
Hardness
Ordination techniques
Paleoenvironmental bioindicators
South American Arid Diagonal
bioindicator
conductivity
diatom
lake ecosystem
mollusc
ordination
paleoenvironment
qualitative analysis
Quaternary
semiarid region
shallow water
Argentina
Pampas
description The aim of this study was to assess the potential of diatoms and mollusks as paleoenvironmental indicators in semiarid lakes of the Argentinean Pampas. At each lake, physical and chemical variables were quantified, and diatoms and mollusks collected. The relationships between environmental variables and biological assemblages were explored through ordination techniques. Lakes were highly alkaline (pH 9.5-10.5), and varied significantly in conductivity (0.2-15.7mS/cm) and hardness (120-1874mg/l CaCO 3). A total of 79 diatom and two mollusk species were identified. The highest percentage variance in diatom data was explained by hardness, conductivity, and mud percentage. Mollusk variability was significantly related to conductivity, hardness, and vegetation cover. Diatom-based ordination of sites accurately reflected the main environmental gradients characteristic of the region, while the resolution provided by mollusk-based ordinations was lower, mainly as consequence of the wide ranges of tolerance to hardness and conductivity exhibited by the two species represented. Hence, while the use of mollusks as paleoenvironmental indicators is only valid at a large, regional scale, diatoms allow discriminating local conditions and subtle environmental differences. As a consequence, the results emphasize the use of mollusks as qualitative and semi-quantitative indicators, while the strong statistical relationship between diatoms and climate-driven environmental parameters highlights their potential use as quantitative indicators of Quaternary climatic changes in the semiarid Pampas. © 2011 Elsevier Ltd.
title Distribution of diatoms and mollusks in shallow lakes from the semiarid Pampa region, Argentina: Their relative paleoenvironmental significance
title_short Distribution of diatoms and mollusks in shallow lakes from the semiarid Pampa region, Argentina: Their relative paleoenvironmental significance
title_full Distribution of diatoms and mollusks in shallow lakes from the semiarid Pampa region, Argentina: Their relative paleoenvironmental significance
title_fullStr Distribution of diatoms and mollusks in shallow lakes from the semiarid Pampa region, Argentina: Their relative paleoenvironmental significance
title_full_unstemmed Distribution of diatoms and mollusks in shallow lakes from the semiarid Pampa region, Argentina: Their relative paleoenvironmental significance
title_sort distribution of diatoms and mollusks in shallow lakes from the semiarid pampa region, argentina: their relative paleoenvironmental significance
publishDate 2012
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01401963_v78_n_p65_Hassan
http://hdl.handle.net/20.500.12110/paper_01401963_v78_n_p65_Hassan
_version_ 1768542262301556736

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