Estado nutricional de mudas de baru (Dipteryx alata) em área de recuperação e remanescentes de cerrado

The Dipteryx alata is a tree specie with possibility of use in human and animal nutrition, and in the pharmaceutical industry. For reclamation of degraded areas, the revegetation has been an alternative, however, requires fertilizer addition. The objectives of this study were to evaluate the nutritional status and growth of Dipteryx alata seedlings, introduced in degraded soil under recovery process, with residues (organic and agroindustrial), compared to collected seedlings in preserved Cerrado, and evaluate the residues impact on soil chemical properties. In this work the degraded soil received the incorporation of residues, organic - RO (macrophytes) and agroindustrial - RA (ash derived from burning bagasse from sugarcane), with the following doses: 0, 16 and 32 t ha- 1 and 0, 15, 30 and 45 t ha-1 respectively. Within three months of incorporation of residues into the degraded soil, the D. alata seedlings were introduced in the experimental area, and 12 months later were evaluated for height, stem diameter, chlorophyll content and leaf contents of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn. For purposes of comparison, the foliar concentration of those elements was determined in Dipteryx alata seedlings collected in preserved Cerrado area. Concomitant with the collect of leaves, at Cerrado and experimental area, soil was collected (0.0 - 0.20m deep) for evaluation of chemical parameters (P, OM, pH, K, Ca, Mg, H + Al, Al, Cu, Fe, Mn and Zn). Comparing the seedlings collected in the Cerrado with the seedlings from experimental area it is observed that the leaf concentration of N, P, K and Mg was higher in seedlings from preserved Cerrado in relation to those introduced in the experimental area. Fe, Mn and Zn, have lower foliar concentration in plants collected in the Cerrado, in the case of Mn the worst results occur in the absence of macrophytes indicating the importance of organic residue. The foliar concentration of Ca, S and Cu was similar in...

Differences in the ichthyofauna feeding habits among lateral lagoons and the river channel in a large reservoir

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Enriquecimento de amido de biomassa produzida em lagoa de lemna utilizando a espécie Landoltia punctata

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

An analysis of publications on invasive macrophytes in aquatic ecosystems

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Aquatic macrophyte distribution in relation to water and sediment conditions in the Itaipu Reservoir, Brazil

Aquatic macrophyte community distribution along the eastern shoreline of the Itaipu Reservoir (one of the South America's largest impoundments) is described in relation to limnological and sedimentological factors. The central body of the reservoir is mesotrophic, while the arms (flooded influent river valleys) along the eastern shore may be oligo-mesotrophic to eutrophic, depending on time of year and sub-catchment characteristics. Macrophyte community composition and species cover were surveyed at 30 sites in four arms, in relation to sediment total P and organic matter; underwater light regime; and water total P and Kjeldahl N concentration, alkalinity, conductivity, depth and pH. Seventeen euhydrophyte and six emergent macrophyte species were recorded. Large stands of Egeria najas dominated the euhydrophyte vegetation, together with free-floating weed species (Pistia stratiotes Linn., Salvinia auriculata Aublet and Eichhornia crassipes (Mart.) Solms.). Canonical Correspondence Analysis of the data showed that two sets of variables were important predictors of aquatic macrophyte community structure. Floating macrophyte assemblage was closely related to concentration of nutrients in both water and sediment, while light penetration was the strongest predictor of submerged species occurrence. Although a large number of potential nuisance species were present, dense growths were restricted to shallower areas of the Itaipu Reservoir, causing localised problems. The possibility of increasing interference by these plants with fisheries, recreational use, transport and hydroelectricity generation suggests a need for continued monitoring of weed distribution and abundance, and investigation of appropriate management measures.

Submerged macrophytes height estimation by echosounder data sample

Traditional methods of submerged aquatic vegetation (SAV) survey last long and then, they are high cost. Optical remote sensing is an alternative, but it has some limitations in the aquatic environment. The use of echosounder techniques is efficient to detect submerged targets. Therefore, the aim of this study is to evaluate different kinds of interpolation approach applied on SAV sample data collected by echosounder. This study case was performed in a region of Uberaba River - Brazil. The interpolation methods evaluated in this work follow: Nearest Neighbor, Weighted Average, Triangular Irregular Network (TIN) and ordinary kriging. Better results were carried out with kriging interpolation. Thus, it is recommend the use of geostatistics for spatial inference of SAV from sample data surveyed with echosounder techniques. © 2012 IEEE.

Water quality and communities associated with macrophytes in a shallow water-supply reservoir on an aquaculture farm

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A comparative study of Odonata (Insecta) in aquatic ecosystems with distinct characteristics

The objective of this study was to compare the richness and density of Odonata larvae in four distinct environments: lotic with large pollutant loads, lotic with small pollutant loads, lentic disconnected from a river and lentic connected to a river, as well as to record the physical and chemical parameters of the water in the four environments. We identified a total of 1,302 Odonata larvae in the four habitats. The environmental variables measured were: dissolved oxygen, pH, conductivity, suspended matter, air and water temperature, precipitation, depth, and the biomass of the macrophytes. The lentic habitats exhibited a greater Odonata larvae density in relation to the lotic habitats, except during April and December of 2006. The Guareí River, however, presented an elevated conductivity, possibly because of a greater quantity of pollutants it received during the period between June and September of 2006, and it showed a higher density of Odonata larvae in comparison to the Paranapanema River. The temperature and the dissolved oxygen on the water surface were, respectively, greater and smaller in the lakes in comparison to the rivers. In spite of the Odonata density being higher in the lentic ecosystems in comparison to the lotic, the richness was not altered during the period studied. Nevertheless, the genera composition was distinct, showing that some taxa show a certain preference for certain types of ecosystems like Calopterygidae and Neogomphus, which were shown exclusively in the Paranapanema River.

Development of a new analytical approach based on cellulose membrane and chelator for differentiation of labile and inert metal species in aquatic systems

A new procedure was developed in this study, based on a system equipped with a cellulose membrane and a tetraethylenepentamine hexaacetate chelator (MD-TEPHA) for in situ characterization of the lability of metal species in aquatic systems. To this end, the DM-TEPHA system was prepared by adding TEPHA chelator to cellulose bags pre-purified with 1.0 mol L-1 of HCl and NaOH solutions. After the MD-TEPHA system was sealed, it was examined in the laboratory to evaluate the influence of complexation time (0-24 h), pH (3.0, 4.0, 5.0, 6.0 and 7.0), metal ions (Cu, Cd, Fe, Mn and Ni) and concentration of organic matter (15, 30 and 60 mg L-1) on the relative lability of metal species by TEPHA chelator. The results showed that Fe and Cu metals were complexed more slowly by TEPHA chelator in the MD-TEPHA system than were Cd, Ni and Mn in all pH used. It was also found that the pH strongly influences the process of metal complexation by the MD-TEPHA system. At all the pH levels, Cd, Mn and Ni showed greater complexation with TEPHA chelator (recovery of about 95-75%) than did Cu and Fe metals. Time also affects the lability of metal species complexed by aquatic humic substances (AHS); while Cd, Ni and Mn showed a faster kinetics, reaching equilibrium after about 100 min, and Cu and Fe approached equilibrium after 400 min. Increasing the AHS concentration decreases the lability of metal species by shifting the equilibrium to AHS-metal complexes. Our results indicate that the system under study offers an interesting alternative that can be applied to in situ experiments for differentiation of labile and inert metal species in aquatic systems. (c) 2006 Elsevier B.V. All rights reserved.

Direct determination of Cu, Cd, Ni and Pb in aquatic humic substances by graphite furnace atomic absorption spectrometry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ecotoxicology of Nano-TiO2 An Evaluation of its Toxicity to Organisms of Aquatic Ecosystems

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Characterization of the Interactions between Endocrine Disruptors and Aquatic Humic Substances from Tropical Rivers

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Utilization of macrophyte biofilter in effluent from aquaculture: I. Floating plant

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeitos do manejo de Eichhornia crassipes sobre a qualidade da água em condições de mesocosmos

As macrófitas, apesar da enorme importância na dinâmica do ambiente aquático, quando formam extensas e densas colonizações, promovem uma série de prejuízos ao ambiente e aos usos múltiplos dos reservatórios. Nessas situações, há necessidade de redução de seu tamanho populacional, seja reduzindo as condições favoráveis ao crescimento, seja por meio do controle direto das plantas. Dentre as macrófitas aquáticas que promovem esses tipos de problema, o aguapé (Eichhornia crassipes) é considerada a mais importante. Seu controle é praticado em todo o mundo. O diquat tem sido bastante utilizado para o controle desta planta, em razão de seu baixo custo, eficácia, rapidez de controle e baixa toxicidade no ambiente aquático. O objetivo do presente trabalho foi avaliar os possíveis impactos causados pelo controle de Eichhornia crassipes sobre algumas características de qualidade da água em mesocosmos. Para isso, cinco situações experimentais foram estudadas: CPCH - mesocosmo colonizado por aguapé, o qual foi controlado pela aplicação do herbicida diquat; CPCG - mesocosmo colonizado por aguapé, o qual foi morto por congelamento; CPSH - mesocosmo colonizado com aguapé, sem controle; SPCH - mesocosmo sem macrófitas e com aplicação de diquat na superfície da água; e SPSH - mesocosmo sem macrófitas aquáticas e sem aplicação. O herbicida diquat foi utilizado na dose de 7,0 L da formulação comercial Reward/ha. A temperatura foi mais elevada nos mesocosmos sem plantas, devido à maior incidência de raios solares na coluna d'água. As concentrações de oxigênio dissolvido foram menores nos mesocosmos colonizados pelo aguapé e também tiveram rápida queda após o controle das plantas tanto com diquat como por congelamento. O pH da água foi maior nos mesocosmos sem a cobertura da macrófita. Os valores de sólidos totais dissolvidos (STD) e de condutividade elétrica foram maiores nos tratamentos com morte por congelamento e pelo diquat e em mesocosmos colonizados sem controle da macrófita. Esse efeito pode ser devido à presença de material orgânico em suspensão e à maior concentração de nutrientes presentes na água. Comparando os mesocosmos sem plantas, sem e com a aplicação de diquat na superfície da água, os valores das características avaliadas foram estatisticamente similares, levando à conclusão de que as alterações observadas nos fatores analisados decorrem principalmente da decomposição das plantas.

Avaliação da sensibilidade de diversas espécies de plantas daninhas aquáticas ao carfentrazone-ethyl, em ambiente controlado

Plantas aquáticas, especialmente macrófitas, tornam-se sério problema em hidrelétricas, afetando a múltipla utilização dos corpos d'água, incluindo produção de peixes e atividades de pesca, perdas d'água por evapotranspiração, esportes aquáticos, canoagem, irrigação e produção de energia nas usinas hidrelétricas. Com o objetivo de analisar o potencial de uso do carfentrazone-ethyl no controle das principais plantas daninhas aquáticas no Brasil, foi instalado um experimento em vasos com água. Utilizaram-se os seguintes tratamentos herbicidas (g i.a. ha-1): carfentrazone-ethyl a 15, 30 e 60; glyphosate a 4.536; 2,4-D a 4.690; imazapyr a 1.250; e uma testemunha sem herbicida. Esses tratamentos foram testados nas seguintes espécies: Eichhornia crassipes, Salvinia auriculata, Pistia stratiotes, Myriophyllum aquaticum, Brachiaria arrecta, Hydrocotyle umbellata, Typha sp. e Echinochloa polystachya. As avaliações foram efetuadas aos 7, 14, 21 e 28 dias após os tratamentos. Os resultados mostraram que o carfentrazone-ethyl foi eficiente no controle de E. crassipes (maior dose) e P. stratiotes (duas maiores doses), com efeito supressivo sobre S. auriculata. Foi observado que nas outras plantas daninhas estudadas não houve eficiência de controle.