Top-down and bottom-up regulation of planktonic communities in a warm temperate wetland

This field experimental study simultaneously analysed the effects of predation (top-down) and nutrients (bottom-up) on planktonic communities (phytoplankton, zooplankton, heterotrophic nanoflagellates and ciliates) in a warm temperate wetland in South America. The top-down and bottom-up controls wer...

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Autor principal: Sinistro, Rodrigo
Publicado: 2010
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01427873_v32_n2_p209_Sinistro
http://hdl.handle.net/20.500.12110/paper_01427873_v32_n2_p209_Sinistro
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spelling paper:paper_01427873_v32_n2_p209_Sinistro2023-06-08T15:11:32Z Top-down and bottom-up regulation of planktonic communities in a warm temperate wetland Sinistro, Rodrigo abundance ciliate flagellate heterotrophy lacustrine deposit mesocosm nutrient omnivory phytoplankton planktivore predation teleost wetland zooplankton South America Ciliophora Jenynsia This field experimental study simultaneously analysed the effects of predation (top-down) and nutrients (bottom-up) on planktonic communities (phytoplankton, zooplankton, heterotrophic nanoflagellates and ciliates) in a warm temperate wetland in South America. The top-down and bottom-up controls were investigated by assessing the impact of omnivorous-planktivorous fish (Jenynsia sp.) and the effects of nutrient input from natural lake sediments, respectively. Three treatments and a control were run in triplicate in mesocosms and samples were taken at Days 0, 3, 7 and 15. The control contained all the planktonic components while treatments included all planktonic components plus the addition of either planktivorous fish (F), natural wetland sediments in dialysis bags (S) or both of them (SF). A bottom-up effect due to nutrient release from sediment (mainly total phosphorus) was noticed in treatments S and SF. Phytoplankton abundance increased in all treatments compared with the control. Thus, phytoplankton appeared to be bottom-up controlled while fish exerted a strong predation pressure on zooplankton (top-down), because treatments F and SF showed a marked decrease in mesozooplankton abundance. The results obtained in this study agree with the hypothesis that phytoplankton regulation by zooplankton might be weaker in warm temperate systems than in temperate ones. Fil:Sinistro, R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2010 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01427873_v32_n2_p209_Sinistro http://hdl.handle.net/20.500.12110/paper_01427873_v32_n2_p209_Sinistro
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic abundance
ciliate
flagellate
heterotrophy
lacustrine deposit
mesocosm
nutrient
omnivory
phytoplankton
planktivore
predation
teleost
wetland
zooplankton
South America
Ciliophora
Jenynsia
spellingShingle abundance
ciliate
flagellate
heterotrophy
lacustrine deposit
mesocosm
nutrient
omnivory
phytoplankton
planktivore
predation
teleost
wetland
zooplankton
South America
Ciliophora
Jenynsia
Sinistro, Rodrigo
Top-down and bottom-up regulation of planktonic communities in a warm temperate wetland
topic_facet abundance
ciliate
flagellate
heterotrophy
lacustrine deposit
mesocosm
nutrient
omnivory
phytoplankton
planktivore
predation
teleost
wetland
zooplankton
South America
Ciliophora
Jenynsia
description This field experimental study simultaneously analysed the effects of predation (top-down) and nutrients (bottom-up) on planktonic communities (phytoplankton, zooplankton, heterotrophic nanoflagellates and ciliates) in a warm temperate wetland in South America. The top-down and bottom-up controls were investigated by assessing the impact of omnivorous-planktivorous fish (Jenynsia sp.) and the effects of nutrient input from natural lake sediments, respectively. Three treatments and a control were run in triplicate in mesocosms and samples were taken at Days 0, 3, 7 and 15. The control contained all the planktonic components while treatments included all planktonic components plus the addition of either planktivorous fish (F), natural wetland sediments in dialysis bags (S) or both of them (SF). A bottom-up effect due to nutrient release from sediment (mainly total phosphorus) was noticed in treatments S and SF. Phytoplankton abundance increased in all treatments compared with the control. Thus, phytoplankton appeared to be bottom-up controlled while fish exerted a strong predation pressure on zooplankton (top-down), because treatments F and SF showed a marked decrease in mesozooplankton abundance. The results obtained in this study agree with the hypothesis that phytoplankton regulation by zooplankton might be weaker in warm temperate systems than in temperate ones.
author Sinistro, Rodrigo
author_facet Sinistro, Rodrigo
author_sort Sinistro, Rodrigo
title Top-down and bottom-up regulation of planktonic communities in a warm temperate wetland
title_short Top-down and bottom-up regulation of planktonic communities in a warm temperate wetland
title_full Top-down and bottom-up regulation of planktonic communities in a warm temperate wetland
title_fullStr Top-down and bottom-up regulation of planktonic communities in a warm temperate wetland
title_full_unstemmed Top-down and bottom-up regulation of planktonic communities in a warm temperate wetland
title_sort top-down and bottom-up regulation of planktonic communities in a warm temperate wetland
publishDate 2010
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01427873_v32_n2_p209_Sinistro
http://hdl.handle.net/20.500.12110/paper_01427873_v32_n2_p209_Sinistro
work_keys_str_mv AT sinistrorodrigo topdownandbottomupregulationofplanktoniccommunitiesinawarmtemperatewetland
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