Do steady state assemblages occur in shallow lentic environments from wetlands?

This study was conducted in a wetland on the Lower Paraná River (Argentina). Algal assemblages from a permanent shallow lake, three relict oxbow lakes (ROL) and an isolated small pond were sampled fortnightly during the spring-summer time of 1998-99. The algal assemblages strongly differed among the...

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Autores principales: O'Farrell, I., Sinistro, R., Izaguirre, I., Unrein, F.
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00188158_v502_n_p197_OFarrell
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spelling todo:paper_00188158_v502_n_p197_OFarrell2023-10-03T14:15:57Z Do steady state assemblages occur in shallow lentic environments from wetlands? O'Farrell, I. Sinistro, R. Izaguirre, I. Unrein, F. Algal associations Disturbance Macrophyte South America Steady state Wetland Algae Bacteria Biodiversity Biomass Vegetation Wetlands Ecological conditions Marine biology algal community community structure ecological stability lentic environment steady-state equilibrium wetland Argentina Parana River South America algae Bacillariophyta Bacteria (microorganisms) Chroococcales Cryptomonas Cyanobacteria Euglena Monoraphidium Oscillatoriales Peridinium Siganus This study was conducted in a wetland on the Lower Paraná River (Argentina). Algal assemblages from a permanent shallow lake, three relict oxbow lakes (ROL) and an isolated small pond were sampled fortnightly during the spring-summer time of 1998-99. The algal assemblages strongly differed among the permanently vegetated ROLs and the shallow lake and small pond, both temporarily covered by floating macrophytes. Anoxic conditions and poor light penetration have been pointed out in previous studies to be the leading factors in the selection of algal species in this wetland. Two or three Cyanobacteria species and some large pennate diatoms dominated the algal biomass in the ROLs, whereas only the former taxa contributed significantly to density. Assemblages were characterised by their low diversity and species richness; the highest SIMI values between consecutive samplings were registered in the ROLs. Even though some characteristics of the Z and S2 Reynolds associations describe the ROLs assemblages, they do not strictly match with them. Changes in algal density and biomass were more pronounced in the shallow lake. An alternative dominance of Cryptomonas spp., Peridinium spp., Euglena spp., Monoraphidium spp., Oscillatoriales and Chroococcales occurred, with a consequent replacement of the Y, Lo, W1 X 1,S2, K, and F Reynolds associations. Variation in the macrophytic cover of the small pond accounted for the fluctuations in its algal composition. When the cover was complete, the assemblages resembled those of the ROLs, whereas when its surface was free of plants, they were more similar to those of the shallow lake. Steady state assemblages related to the persistence of a dense macrophyte cover may be found in wetlands in environments with constant and extreme ecological conditions such as those recorded in the ROLs. In contrast, 'unpredictable' assemblages can be expected in shallow lakes with fluctuating conditions. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00188158_v502_n_p197_OFarrell
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Algal associations
Disturbance
Macrophyte
South America
Steady state
Wetland
Algae
Bacteria
Biodiversity
Biomass
Vegetation
Wetlands
Ecological conditions
Marine biology
algal community
community structure
ecological stability
lentic environment
steady-state equilibrium
wetland
Argentina
Parana River
South America
algae
Bacillariophyta
Bacteria (microorganisms)
Chroococcales
Cryptomonas
Cyanobacteria
Euglena
Monoraphidium
Oscillatoriales
Peridinium
Siganus
spellingShingle Algal associations
Disturbance
Macrophyte
South America
Steady state
Wetland
Algae
Bacteria
Biodiversity
Biomass
Vegetation
Wetlands
Ecological conditions
Marine biology
algal community
community structure
ecological stability
lentic environment
steady-state equilibrium
wetland
Argentina
Parana River
South America
algae
Bacillariophyta
Bacteria (microorganisms)
Chroococcales
Cryptomonas
Cyanobacteria
Euglena
Monoraphidium
Oscillatoriales
Peridinium
Siganus
O'Farrell, I.
Sinistro, R.
Izaguirre, I.
Unrein, F.
Do steady state assemblages occur in shallow lentic environments from wetlands?
topic_facet Algal associations
Disturbance
Macrophyte
South America
Steady state
Wetland
Algae
Bacteria
Biodiversity
Biomass
Vegetation
Wetlands
Ecological conditions
Marine biology
algal community
community structure
ecological stability
lentic environment
steady-state equilibrium
wetland
Argentina
Parana River
South America
algae
Bacillariophyta
Bacteria (microorganisms)
Chroococcales
Cryptomonas
Cyanobacteria
Euglena
Monoraphidium
Oscillatoriales
Peridinium
Siganus
description This study was conducted in a wetland on the Lower Paraná River (Argentina). Algal assemblages from a permanent shallow lake, three relict oxbow lakes (ROL) and an isolated small pond were sampled fortnightly during the spring-summer time of 1998-99. The algal assemblages strongly differed among the permanently vegetated ROLs and the shallow lake and small pond, both temporarily covered by floating macrophytes. Anoxic conditions and poor light penetration have been pointed out in previous studies to be the leading factors in the selection of algal species in this wetland. Two or three Cyanobacteria species and some large pennate diatoms dominated the algal biomass in the ROLs, whereas only the former taxa contributed significantly to density. Assemblages were characterised by their low diversity and species richness; the highest SIMI values between consecutive samplings were registered in the ROLs. Even though some characteristics of the Z and S2 Reynolds associations describe the ROLs assemblages, they do not strictly match with them. Changes in algal density and biomass were more pronounced in the shallow lake. An alternative dominance of Cryptomonas spp., Peridinium spp., Euglena spp., Monoraphidium spp., Oscillatoriales and Chroococcales occurred, with a consequent replacement of the Y, Lo, W1 X 1,S2, K, and F Reynolds associations. Variation in the macrophytic cover of the small pond accounted for the fluctuations in its algal composition. When the cover was complete, the assemblages resembled those of the ROLs, whereas when its surface was free of plants, they were more similar to those of the shallow lake. Steady state assemblages related to the persistence of a dense macrophyte cover may be found in wetlands in environments with constant and extreme ecological conditions such as those recorded in the ROLs. In contrast, 'unpredictable' assemblages can be expected in shallow lakes with fluctuating conditions.
format JOUR
author O'Farrell, I.
Sinistro, R.
Izaguirre, I.
Unrein, F.
author_facet O'Farrell, I.
Sinistro, R.
Izaguirre, I.
Unrein, F.
author_sort O'Farrell, I.
title Do steady state assemblages occur in shallow lentic environments from wetlands?
title_short Do steady state assemblages occur in shallow lentic environments from wetlands?
title_full Do steady state assemblages occur in shallow lentic environments from wetlands?
title_fullStr Do steady state assemblages occur in shallow lentic environments from wetlands?
title_full_unstemmed Do steady state assemblages occur in shallow lentic environments from wetlands?
title_sort do steady state assemblages occur in shallow lentic environments from wetlands?
url http://hdl.handle.net/20.500.12110/paper_00188158_v502_n_p197_OFarrell
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AT sinistror dosteadystateassemblagesoccurinshallowlenticenvironmentsfromwetlands
AT izaguirrei dosteadystateassemblagesoccurinshallowlenticenvironmentsfromwetlands
AT unreinf dosteadystateassemblagesoccurinshallowlenticenvironmentsfromwetlands
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