Effects of limnological and morphometric factors upon Zmin, Zmax and width of Egeria spp stands in a tropical reservoir
In this work, regression analyses were used to test the effects of fetch, littoral slope and Secchi disk depth upon the stand width (Wi) and maximum (Zmax) and minimum (Zmin) colonization depths of Egeria spp in a large tropical reservoir (Rosana Reservoir). Littoral slope was the only variable corr...
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| Format: | Article |
| Language: | English |
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Instituto de Tecnologia do Paraná (Tecpar)
2009-04-01
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| Series: | Brazilian Archives of Biology and Technology |
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| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132009000200016 |
| _version_ | 1811304190254776320 |
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| author | Sandra Andréa Pierini Sidinei Magela Thomaz |
| author_facet | Sandra Andréa Pierini Sidinei Magela Thomaz |
| author_sort | Sandra Andréa Pierini |
| collection | DOAJ |
| description | In this work, regression analyses were used to test the effects of fetch, littoral slope and Secchi disk depth upon the stand width (Wi) and maximum (Zmax) and minimum (Zmin) colonization depths of Egeria spp in a large tropical reservoir (Rosana Reservoir). Littoral slope was the only variable correlated with Wi, which was larger in locations with lower slopes. The higher Wi values (up to 260m) were found in locations where slopes were lower than 0.05 m.m-1. Zmin and Zmax were correlated positively with fetch. Nevertheless, different relationships were found at lower and higher fetch values observed in the arms and in the main body of the reservoir, respectively. At lower values, Secchi disk depth was the main variable explaining Egeria Zmax. On the other hand, in locations where fetch was longer (i.e. in the main axis of the reservoir), it was the only variable that explained Zmax significantly. Despite the great variability, the results indicated that the measured limnological (Secchi disk) and morphometric (fetch and slope) variables were important determinants of Egeria spp colonization in the Rosana Reservoir.<br>Regressões múltiplas foram utilizadas com o objetivo de testar os efeitos do fetch (distância livre para ação do vento), declividade da região litorânea e da profundidade do disco de Secchi sobre a largura e os limites de colonização superior (Zmax) e inferior (Zmin) de bancos de Egeria spp em um grande reservatório tropical (Reservatório de Rosana). A declividade foi a única variável correlacionada com a largura dos bancos, que foi maior em locais com menor declividade. Os maiores valores da largura (até 260m) foram registrados em locais com declividade inferior a 0,05 m.m-1. Zmin e Zmax foram correlacionadas positivamente com o fetch. Entretanto, para o Zmax, diferentes relações foram encontradas em valores de fetchs baixos e altos, observados nos braços e no corpo central do reservatório, respectivamente. Em valores de fetch mais baixos, a profundidade de disco de Secchi foi a principal variável que explicou Zmax dos estandes de Egeria. Por outro lado, em valores de fetch mais elevados (obtidos no corpo central do reservatório), o fetch foi a única variável significativamente correlacionada com a Zmax. |
| first_indexed | 2024-04-13T08:01:48Z |
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| institution | Directory Open Access Journal |
| issn | 1516-8913 1678-4324 |
| language | English |
| last_indexed | 2024-04-13T08:01:48Z |
| publishDate | 2009-04-01 |
| publisher | Instituto de Tecnologia do Paraná (Tecpar) |
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| series | Brazilian Archives of Biology and Technology |
| spelling | doaj.art-b723c7c4e97443b2884fdee33dd0b1352022-12-22T02:55:16ZengInstituto de Tecnologia do Paraná (Tecpar)Brazilian Archives of Biology and Technology1516-89131678-43242009-04-0152238739610.1590/S1516-89132009000200016Effects of limnological and morphometric factors upon Zmin, Zmax and width of Egeria spp stands in a tropical reservoirSandra Andréa PieriniSidinei Magela ThomazIn this work, regression analyses were used to test the effects of fetch, littoral slope and Secchi disk depth upon the stand width (Wi) and maximum (Zmax) and minimum (Zmin) colonization depths of Egeria spp in a large tropical reservoir (Rosana Reservoir). Littoral slope was the only variable correlated with Wi, which was larger in locations with lower slopes. The higher Wi values (up to 260m) were found in locations where slopes were lower than 0.05 m.m-1. Zmin and Zmax were correlated positively with fetch. Nevertheless, different relationships were found at lower and higher fetch values observed in the arms and in the main body of the reservoir, respectively. At lower values, Secchi disk depth was the main variable explaining Egeria Zmax. On the other hand, in locations where fetch was longer (i.e. in the main axis of the reservoir), it was the only variable that explained Zmax significantly. Despite the great variability, the results indicated that the measured limnological (Secchi disk) and morphometric (fetch and slope) variables were important determinants of Egeria spp colonization in the Rosana Reservoir.<br>Regressões múltiplas foram utilizadas com o objetivo de testar os efeitos do fetch (distância livre para ação do vento), declividade da região litorânea e da profundidade do disco de Secchi sobre a largura e os limites de colonização superior (Zmax) e inferior (Zmin) de bancos de Egeria spp em um grande reservatório tropical (Reservatório de Rosana). A declividade foi a única variável correlacionada com a largura dos bancos, que foi maior em locais com menor declividade. Os maiores valores da largura (até 260m) foram registrados em locais com declividade inferior a 0,05 m.m-1. Zmin e Zmax foram correlacionadas positivamente com o fetch. Entretanto, para o Zmax, diferentes relações foram encontradas em valores de fetchs baixos e altos, observados nos braços e no corpo central do reservatório, respectivamente. Em valores de fetch mais baixos, a profundidade de disco de Secchi foi a principal variável que explicou Zmax dos estandes de Egeria. Por outro lado, em valores de fetch mais elevados (obtidos no corpo central do reservatório), o fetch foi a única variável significativamente correlacionada com a Zmax.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132009000200016Egeriafetchlittoral slopeSecchi disk |
| spellingShingle | Sandra Andréa Pierini Sidinei Magela Thomaz Effects of limnological and morphometric factors upon Zmin, Zmax and width of Egeria spp stands in a tropical reservoir Brazilian Archives of Biology and Technology Egeria fetch littoral slope Secchi disk |
| title | Effects of limnological and morphometric factors upon Zmin, Zmax and width of Egeria spp stands in a tropical reservoir |
| title_full | Effects of limnological and morphometric factors upon Zmin, Zmax and width of Egeria spp stands in a tropical reservoir |
| title_fullStr | Effects of limnological and morphometric factors upon Zmin, Zmax and width of Egeria spp stands in a tropical reservoir |
| title_full_unstemmed | Effects of limnological and morphometric factors upon Zmin, Zmax and width of Egeria spp stands in a tropical reservoir |
| title_short | Effects of limnological and morphometric factors upon Zmin, Zmax and width of Egeria spp stands in a tropical reservoir |
| title_sort | effects of limnological and morphometric factors upon zmin zmax and width of egeria spp stands in a tropical reservoir |
| topic | Egeria fetch littoral slope Secchi disk |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132009000200016 |
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