Tectonic history and the biogeography of the freshwater fishes from the coastal drainages of eastern Brazil: an example of faunal evolution associated with a divergent continental margin

As drenagens costeiras do leste do Brasil correspondem a ��reas de grande significado biogeogr��fico, apresentando um alto grau de endemismo em sua fauna de peixes. Padr��es filogen��ticos sugerem uma rela����o pr��xima entre os rios que correm para o Atl��ntico a os adjacentes das terras altas do escudo cristalino. Entretanto, pouco tem sido dito sobre a din��mica dos processos geol��gicos relacionados aos eventos cladogen��ticos entre estas ��reas. Padr��es de distribui����o e filogen��ticos sugerem uma ��ntima associa����o com a hist��ria geol��gica da margem continental passiva da Am��rica do Sul, desde o Cret��ceo aos dias atuais. Soerguimentos macrod��micos, rifteamento, movimentos verticais entre blocos falhados e o recuo erosivo da margem leste sul-americana s��o considerados como as principais for��as geol��gicas atuando sobre a distribui����o da ictiofauna de ��gua doce nestas ��reas. A atividade tect��nica associada �� ruptura do Gondwana e separa����o da Am��rica do Sul e ��frica criou seis megadomos que s��o respons��veis por configurar a maior parte do atual curso das principais bacias hidrogr��ficas do escudo cristalino. Com exce����o das bacias localizadas ��s margens de tais megadomos, estes rios desenvolveram longos e sinuosos circuitos sobre o antigo escudo cristalino brasileiro antes de desaguarem no ent��o recentemente aberto Oceano Atl��ntico. Eventos cladogen��ticos iniciais entre drenagens de terras altas do escudo cristalino e tribut��rios do Atl��ntico podem estar associados com processos vicariantes desta fase inicial, e alguns t��xons antigos, basais, grupos-irm��o de t��xons muito inclusivos e de ampla distribui����o s��o encontrados nestas bacias hidrogr��ficas. Mais tarde, a denuda����o erosiva generalizada resultou em um ajuste isost��tico da margem leste da plataforma. Tal ajuste, concomitantemente a reativa����es de antigas zonas de falha, resultou em movimentos verticais entre blocos falhados, dando origem, no sudeste do Brasil, a bacias tafrog��nicas. Tais bacias, como a de Taubat��, S��o Paulo, Curitiba e Volta Redonda, entre outras, capturaram drenagens e fauna de terras altas adjacentes. Os peixes f��sseis da Forma����o Trememb�� (Eoceno-Oligoceno da Bacia de Taubat��) exemplificam este processo. Outros sistemas tafrog��nicos de idade Terci��ria foram tamb��m identificados em outros segmentos da margem continental Atl��ntica, como na Prov��ncia Borborema, no NE do Brasil, com marcada influ��ncia sobre o padr��o de drenagem. Ao mesmo tempo, o recuo erosivo da margem leste da plataforma capturou sucessivamente rios de planalto, os quais se tornaram tribut��rios atl��nticos, evoluindo associados aos principais sistemas de falha. A natureza continuada destes processos explica os padr��es filogen��ticos e de distribui����o miscigenados entre os tribut��rios atl��nticos e as terras altas do escudo cristalino adjacente, especialmente na margem sudeste do continente, representados por sucessivos, cada vez menos inclusivos, grupos irm��os, associados a eventos cladogen��ticos desde o final do Cret��ceo ao presente.

Produtividade do arroz de terras altas em fun����o do manejo do solo e da ��poca de aplica����o de nitrog��nio

O manejo adequado do solo e a identifica����o da ��poca de aplica����o de N podem aumentar, significativamente, a produtividade do arroz de terras altas. Neste contexto, objetivou-se, com este trabalho, avaliar a intera����o do manejo do solo com a ��poca de aplica����o de nitrog��nio, no desenvolvimento e produtividade da cultura. O delineamento experimental utilizado foi o de blocos ao acaso, em esquema fatorial 5x2, sendo 5 tipos de manejo do solo (arado de aiveca e grade niveladora; grade aradora e grade niveladora; escarificador tipo matabroto; SPD; e Aeromix - equipamento de escarifica����o superficial) e duas ��pocas de aplica����o de nitrog��nio (todo N na base, sendo 45 kg ha-1 de nitrog��nio aplicados com adubadora de tra����o mec��nica, 1 dia antes da semeadura do arroz, + 45 kg ha-1 de nitrog��nio aplicados no ato da semeadura; e 45 kg ha-1 de nitrog��nio aplicados no ato da semeadura + 45 kg ha-1 aplicados no in��cio do perfilhamento das plantas), com 4 repeti����es. N��o houve intera����o dos fatores, para a vari��vel estande final de plantas. Nos tratamentos onde houve revolvimento de solo com arado de aiveca e grade, observou-se maior produtividade quando o nitrog��nio foi parcelado. Quando o nitrog��nio foi aplicado todo no plantio, o tratamento com escarificador tipo matabroto apresentou a maior produtividade, diferindo de todos os outros tratamentos. O plantio convencional (aiveca ou grade) apresentou produtividade semelhante ao SPD, quando se aplicou o N todo no plantio.

Desenvolvimento e produtividade de cultivares de arroz de terras altas em fun����o do manejo do solo

A identifica����o de cultivares, para cada tipo de manejo do solo, pode favorecer o aumento da produtividade da cultura do arroz de terras altas. Neste contexto, objetivou-se, com este trabalho, estudar o desempenho de gen��tipos de arroz de terras altas, em dois sistemas de manejo do solo: preparo convencional (PC) e sistema plantio direto (SPD). O estudo foi desenvolvido no munic��pio de Ipameri, GO, em 2008/2009. O delineamento experimental foi em blocos ao acaso, no esquema fatorial 2x8, com dezesseis tratamentos e quatro repeti����es. O primeiro fator foi o sistema de manejo do solo (PC e SPD) e o segundo cultivares (BRS Curinga, BRS Primavera, BRS Monarca, BRS Pepita, BRS Sertaneja, Caraj��s, Caiap�� e Bonan��a). As plantas apresentaram-se mais altas no PC do que no SPD. Quanto ao n��mero de perfilhos por planta, verificou-se, tamb��m, variabilidade nas cultivares, quanto ao tipo de manejo de solo. Constatou-se que o preparo convencional propiciou maiores produtividades (m��dia de 4.349 kg ha-1 que o sistema plantio direto (m��dia de 3.521 kg ha-1, sendo o n��mero de pan��culas por mI;e n��mero de gr��os por pan��cula os componentes de produ����o que mais contribu��ram para esta diferen��a. Todas as cultivares apresentaram diferen��as estat��sticas entre os dois sistemas de manejo do solo, com exce����o da cultivar Caiap��. Nos dois sistemas, Caraj��s foi a mais produtiva e diferiu, estatisticamente, das cultivares BRS Sertaneja e BRS Primavera.

Doses de boro e crescimento radicular e da parte a��rea de cultivares de arroz de terras altas

O crescimento radicular �� favorecido em condi����es adequadas de disponibilidade de boro no solo e, por isto, a aplica����o da dose correta desse micronutriente �� de grande import��ncia, para que n��o ocorra preju��zo no desenvolvimento e na produtividade da cultura de arroz de terras altas, de acordo com a variedade e tipo de solo. O presente trabalho teve como objetivo avaliar a influ��ncia das doses de boro no crescimento radicular e da parte a��rea, em tr��s cultivares de arroz de terras altas. O experimento foi realizado em casa de vegeta����o, em vaso com capacidade de 10 L, que continha 8 dm�� de solo Latossolo Vermelho distr��fico, sendo o delineamento experimental inteiramente casualizado, em esquema fatorial 3 x 3, com quatro repeti����es. Os tratamentos consistiram de tr��s cultivares (Caiap��, Primavera e Maravilha) e tr��s doses de boro (0, 3 e 6 mg dm-3), usando, como fonte, o b��rax. A dose de 6 mg dm-3 foi prejudicial tanto �� produ����o de mat��ria seca da parte a��rea como de raiz para o arroz de terras altas. Al��m de apresentar maior capacidade de absor����o de boro, o cultivar Maravilha apresentou-se mais tolerante �� eleva����o da disponibilidade de B no solo, n��o ocorrendo altera����es de comprimento, di��metro e superf��cie radicular.

Nitrate role in basic cation leaching under no-till

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Caracteriza����o e avalia����o de tr��s grupos de arroz-de-sequeiro de diferentes proced��ncias por meio da sensitividade �� radia����o gama

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

Uso da sensitividade �� radia����o gama na discrimina����o de variedades de arroz-de-sequeiro dos grupos ��ndica e Jap��nica

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

Pulveriza����o em CDA 250 herbicida pendimethalin na cultura do arroz de sequeiro

Foi estudada a viabilidade de utiliza����o da pulveriza����o CDA 25C, na aplica����o do herbicida em pr��-emerg��ncia na cultura do arroz de sequeiro. O herbicida empregado foi o pendimethalin nas doses de 0,0; 1,5; 2,0; 2,5 e 3,0 litro s/ha da formula����o comercial a 50%. A pulveriza����o convencional foi efetuada com bicos 11003 com consumo de 200 litros de calda per hectare. O processo CDA 250 foi aplicado por meio de bico rotativo (Micromax) com dois n��veis de consumo de calda : 50 1/ha e 27 1/ha. Os resultados mostraram que: a) - o m��todo CDA 250 proporciona controle dc mato e produtividade de arroz equivalentes ao m��todo convencional; b) para o bico Micromax, a aplica����o da formula����o comercial de pendimethalin a 50% com vaz��o de 0,48 1/min./bico, a dist��ncia entre bicos deve ser de 1,75 m e para a vaz��o de 0,96 1/min./bloco, essa distancia deve ser de 1,90 m; c)- a aplica����o do pendimethalin 50% C.E. pelo processo CDA 250, empregando 27 litros de calda por hectare foi o processo mais interessante por oferecer vantagens log��sticas apreci��veis.

Diagnosis and environmental planning for Paranagud - PR - Brazil

The main goal of this study was to identify and analyse environmental problems related to human occupation at the south part of the city of Paranagua PR, Brazil, aiming the diagnosis and conceptual evaluation of landscape use. For landscape use assessments and degradation diagnosis purposes, the environment was classified considering mainly geological and geomorphologic characteristics, such as declivity and sediment origin. The identification of potential environmental impacts was made by aerial photographs, Landsat-TM images, photographic records, surface sediment samples, water-column samples, and mainly observation visits to each classified unit. Surface sediment samples were taken with a Petit-Ponar sampler, in 13 station located in Paranagua Bay. In order to characterize the contamination level on sediments, the concentration of the following elements were analysed: arsenic (As), copper (Cu), cadmium (Cd), nickel (Ni), lead (Ph) e zinc (Zn). For the extraction of these elements, samples were treated with HCl 0.1N for 12 hours. This method has the advantage of determining contaminants which are weakly bind to the sediment, thus more available to the system. Analysis were performed by atomic absorption spectroscopy. According to the adopted criteria, sectors were classified as hills, mangroves, continental sediments and beach ridges urban and port industrial. Water quality and concentrations of metallic elements were determined at three sectors one control and two with the influence of urban and port/industrial activities, respectively the major upland impacts found were: deforestation due to disordered occupation, and solid waste emission through domestic and industrial sewage. The diagnosis of the actual situation was used as a basis for a management plan, once it allows the identification of impacts, and consequent environmental irregularities. Based on this considerations, suggestions for land use and management were presented, which offers a better approach for recuperation and protection of the studied ecosystem.

Foraging, diet and community structure in an epigaeic ant (Hymenoptera: Formicidae) assemblage: the role of recruitment

The significance of recruitment systems for community structure of epigaeic ants in a tropical upland forest in southern Brazil was evaluated by examining patterns of spatial occurrence at fixed points. Normal exploratory activity was evaluated with pitfall traps, while the effect of recruitment and diet was evaluated by using honey and sardine baits at the same points. Through techniques developed for environmental impact assessment, the significance of recruitment was evaluated following perturbation, or the placement of bait. Of the 46 species encountered, 15 were sufficiently frequent to study. Of these, only 6 showed significant spatial frequency changes at baits when compared with pitfall trap collections. In one analysis, monthly differences were important for a few smaller species, suggesting thermic limitations, while bait types either increased or decreased spatial point usage. The magnitude of spatial point variation is an index for the strength of recruitment in community organization. Bait types suggest nutritional possibilities of each species. Both recruitment and diet are probably functions of the species composition of the ant community.

Agronomic effectiveness of cationic phosphate impurities present in superphosphate fertilizers as affected by soil pH

The general concept that low-water-soluble phosphorus (P) fertilizers should be more agronomically effective when applied to acidic soils was developed based on sources containing mainly calcium (Ca)-P compounds, but it may not hold true for sources with different chemical composition. To obtain information related to this issue, two important iron (Fe)-potassium (K)-P compounds present in superphosphates [Fe 3 KH 8 (PO 4 ) 6��6H 2 O, H8, and Fe 3 KH 14 (PO 4 ) 8��4H 2 O, H14] were prepared and characterized. These P sources were used to provide 30 and 60 mg P kg -1 as neutral ammonium citrate (NAC)+H 2 O-soluble P. Reagent-grade monocalcium phosphate (MCP) was used as a standard P source with high water solubility with an additional rate of 120 mg P kg -1 included. Also, mixtures of both Fe-K-P compounds and MCP were prepared to provide 0, 25, 50, 75, and 100% of the total P as MCP. All sources were applied to a clayey loamy acid soil (pH 5.3) classified as Rhodic Kanhapludult. The soil was incubated at two rates (0 and 10 g kg -1 ) of lime, which resulted in pH 5.4 and 6.8. Upland rice was cultivated to maturity. The H14 compound confirmed to be a highly effective source of P for the rice plants at both soil pH, as opposed to the H8, which was poorly effective when applied alone. When mixed with water-soluble P (WSP), the H8 was able to provide P to the plants with the maximum yield of upland rice reached with 54.8 and 80.5% of WSP for pH 5.4 and 6.8, respectively. The high agronomic performance of the H14 compound clearly indicates that this low-water-soluble P source cannot be deemed as ineffective at high soil pH. Copyright �� Taylor & Francis Group, LLC.

Uso do regulador de crescimento etil-trinexapac em arroz de terras altas

This work was developed with the objective of evaluating the use of trinexapac-ethyl doses (0, 75, 150, 225 and 300 g of the a.i. ha -1) and application times (active tillering, between active tillering and floral differentiation and at floral differentiation) in upland rice crop development and yield. The experiment was carried out in Selv��ria-MS, during the agricultural year of 2006/07. Application of 150 g ha -1 of trinexapac-ethyl in Primavera rice cultivar at panicle initiation differentiation reduces plants height, 0.40 m on average comparing to other times, with lodging absence. Trinexapac-ethyl promotes lange number of abnormal grains, reduction of grain yields in doses above 150 g ha -1, when applied in panicle initiation differentiation stadium. Application of 150 g ha -1 of trinexapac-ethyl at any time does not interfere in crop yield.

Glyphosate como regulador de crescimento em arroz de terras altas

The lodging of some rice cultivars at harvest time can lead to significant losses in yield, and the inappropriate water and nitrogen management, under high-tech conditions, can aggravate the problem. The use of vegetal regulators is an alternative to reduce lodging, however, information on this topic are rare. The study aimed to evaluate the application of glyphosate sub doses (26 g ha -1, 52 g ha -1, 78 g ha -1, 104 g ha -1, 130 g ha -1, 156 g ha -1, and 182 g ha -1) on agronomical traits, development, and yield of upland rice crops irrigated by aspersion, during the floral differentiation period. The experiment was carried out in Selv��ria, Mato Grosso do Sul State, Brazil, through the agricultural years of 2008/2009 and 2009/2010. The increase of glyphosate sub doses, at the floral differentiation period of the Primavera cultivar, reduced the plants height, panicle size, and, consequently, yield. Sub doses higher than or equal to 78 g ha -1 eliminated the plants lodging process.

An��lise de crescimento e produtividade de cultivares de arroz de terras altas dos tipos tradicional, intermedi��rio e moderno

The growth analysis allows the characterization and understanding of the upland rice cultivars development. This study aimed at characterizing, by using the growth analysis, the physiological components and agronomic performance, as well as the differences among traditional, intermediate and modern upland rice cultivars. The experiment was conducted under upland rice conditions, favored by the use of supplementary irrigation. The experimental design was randomized blocks, with three treatments consisting of traditional (Caiap��), modern (Maravilha) and intermediate (BRS Primavera) cultivars and eight replications. The leaf area index (LAI), instantaneous growth rate (IGR), relative growth rate (RGR), net assimilation rate (NAR) and specific leaf area (SLA), as well as grain yield and yield components, were evaluated. The intermediate and traditional cultivars presented the highest total dry matter accumulation rate, while the traditional and modern ones showed the highest LAI. The intermediate cultivar presented the highest IGR, RGR, NAR and SLA levels, as well as the highest grain yield, as a consequence of the higher spikelet fertility and 1,000 grain mass.

Deposi����o de s��lica e teor de nitrog��nio e sil��cio em arroz

The nitrogen fertilization is an important practice to reach high productivity, however, nitrogen high level can cause lodging and make the plants more sensitive to disease. Numerous studies has demonstrate that a lot of grasses accumulate silicon at its tissues, and the biggest part of this element is deposited on the leaf, that would work like a mechanical barrier to diseases come in. However, high levels of nitrogen can reduce the silica deposition at the plants. The objective of this study was to evaluate silicon and nitrogen content in shoot and silica deposition in upland rice leaf as a result of Si and N levels. The experimental design used was completely randomized in factorial schema 3 x 2 with five replications. The treatments consisted from levels of N (5, 75 and 150 mg dm-3 of soil) in urea form and two levels of SiO2 (0 e 400 mg dm-3) in calcium silicate form (Wollastonita). The increased of urea fertilization reduced the silicon content of rice plants and the silica deposition at the external cells wall the epidermal rice leafs.