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| Registros recuperados: 10 | |
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| Pelicice,Fernando Mayer; Thomaz,Sidinei Magela; Agostinho,Angelo Antonio. |
| Submerged macrophytes play an important role in structuring habitats and, therefore, in determining patterns of aquatic biodiversity. Because these plants are widespread in shallow areas of many Neotropical reservoirs, the present work investigated if variables related to habitat structure, measured in patches of submerged macrophytes (Egeria densa and E. najas), can be used to predict fish assemblage attributes (fish density and species richness). Based on patch characteristics at fine spatial extents (macrophyte patches within reservoir arms), we considered plant biomass, volume and proportional volume (i.e. percentage of macrophyte volume in the water column) as potential predictors. Fish and macrophytes were sampled with a 1-m² throw trap in littoral... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aquatic plants; Habitat structure; Predictive ecology; Variability; Tropical reservoir. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252008000400001 |
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| Pierini,Sandra Andréa; Thomaz,Sidinei Magela. |
| No presente trabalho são discutidos alguns aspectos teóricos dos mecanismos e adaptações empregados pela vegetação submersa para maximizar o aproveitamento do carbono inorgânico na água. O tipo de estratégia utilizada pelas macrófitas aquáticas submersas deve-se a diferenças genéticas entre as espécies e também às condições ambientais predominantes. Vários mecanismos fisiológicos e morfológicos, como a utilização do metabolismo C4, do ácido das crassuláceas (CAM), a utilização do bicarbonato (HCO3-), a utilização do CO2 da água intersticial do sedimento e o desenvolvimento de folhas aéreas foram considerados as principais adaptações para evitar a limitação do carbono no ambiente aquático. De relevância ecológica, a utilização destas diferentes estratégias... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Planta submersa; Carbono inorgânico. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062004000300020 |
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| Dibble,Eric David; Thomaz,Sidinei Magela. |
| We used a computerized approach to measure spatial complexity for the structural habitat provided by eight aquatic plant species collected from backwater lagoons located in the Upper Paraná River floodplain, Brazil. The plant species were: Cabomba furcata Schult. and Schult.f., Eichhornia azurea (Sw.) Kunth (stems and roots), Eichhornia crassipes (Mart.) Solms, Egeria najas Planchon, Heteranthera cf. zosterifolia, Potamogeton cf pusillus, Utricularia foliosa L., and Nymphaea amazonum Mart. and Zucc. The upper 0.5 m length of the terminal stems was quantified for complexity. Mean frequency and length of the interstices were significantly different among plant species. Spatial complexity varied (F = 17.30; p < 0.0001) among the different plant species... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aquatic plant structure; Spatial complexity; Architecture; Habitat heterogeneity. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132006000400010 |
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| Pierini,Sandra Andréa; Thomaz,Sidinei Magela. |
| 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... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Egeria; Fetch; Littoral slope; Secchi disk. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132009000200016 |
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| Evangelista,Heloísa Beatriz Antoniazi; Thomaz,Sidinei Magela; Evangelista,Luiz Roberto. |
| In this work, a recently proposed diversity index based on Patil and Taillie parametric diversity measure (or Tsallis entropy), Sq*, was applied to samples (presence-absence data) of macrophytes from the Itaipu Reservoir, Brazil. This new index was the value of the family of indices Sq for a specific evenness of a sample. Results demonstrated that the Shannon index and species richness showed expressively high correlation with the Sq*; however, the evenness had low correlation coefficients with the index Sq*, indicating that Sq* was particularly sensitive to rarity and species richness. On the other hand, the weak correlations of this index with evenness demonstrated that it was less sensitive to species relative abundances. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Tsallis entropy; Macrophytes; Reservoir; Shannon; Simpson. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132012000200014 |
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| Sousa,Wilson Treger Zydowicz; Panitz,Clarice Maria Neves; Thomaz,Sidinei Magela. |
| Vertical flow constructed wetlands, planted with and without Spartina alterniflora, were tested for the treatment of mariculture wastewater. Wetlands with and without the emergent macrophyte produced reductions of 89 and 71% for inorganic solids, 82 and 96% for organic solids, 51 and 63% for total nitrogen, 82 and 92% for ammoniacal nitrogen, 64 and 59% for orthophosphate, and 81 and 89% for turbidity, respectively. Wetlands with S. alterniflora showed denitrification tendencies, while wetlands without S. alterniflora had higher oxygen levels leading to nitrification. The results suggest the fundamental role of oxygen controlling the purification processes as well as the potential of constructed wetlands to treat mariculture effluents. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Artificial wetlands; Dissolved oxygen; Nitrification; Denitrification; Pollutant removal; Mariculture effluent. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132011000200024 |
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| Thomaz,Sidinei Magela; Bini,Luis Maurício; Souza,Maria Conceição de; Kita,Kazue Kawakita; Camargo,Antonio Fernando Monteiro. |
| In a survey of the aquatic macrophytes of the Itaipu Reservoir, we identified 62 taxa in 25 families and 42 genera. The highest number taxa was observed for the emergent macrophytes (40 taxa). Reduced fluctuation in water level, increased light penetration, and sediment enrichment by nutrients and organic matter following the formation of the reservoir favored the appearance of a species-rich community of submerged macrophytes (23% of the taxa identified). The aquatic macrophytes were found mainly near the mouths of the main tributaries of the reservoir, in shallow area of depth less than 2 meters. In addition to the shallow depth, the greater nutrient input from the tributaries and relative protection from wind explained this distribution. Among the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Nuisance species; Aquatic macrophytes; Itaipu reservoir; Egeria najas; Egeria densa. |
| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89131999000100003 |
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| Registros recuperados: 10 | |
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