951 resultados para SUL RIVER-BASIN


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The occurence of carbonatic rocks defines a typical type of relief, called karst, that, by its geomorphology and hydrology, usually differs from the surrounding landscape. In the upper São Francisco river basin, some striking remnants of vegetation associated to karst can be found, which are locally knwon as Mata de Pains. In this region, a mosaic of different physiognomies, including forests and open areas, which present noteworthy plant diversity, composes the vegetation. The aim of this study is to provide an inventory of angiosperm species in areas of carbonatic rocks outcrops in the upper São Francisco river basin karst region, as well as analyze the floristic relationship of the study area with different Brazilian phytogeographic domains. Fieldwork was performed during the period of 2002 a 2006, when collections of fertile speciemns were done in areas associated to carbonatic rock outcrops. During the study, 1512 exsicates were incorporated to BHCB herbarium collection. A total of 456 angiosperm species were inventoried, distributed in 299 genera and 77 families. Herbaceous habit was better represented, with 161 species, followed by shrubs and trees (111 species each) and lianas (73 species). The flora of the study area presents more influence of the Mata Atlântica domain (Atlantic Rain Forest), followed by, in order of importance, Cerrado, Amazonia, Caatinga, Pantanal and Pampa. Floristic surveys in different karst regions inserted in different phytogeographic domains may, together, provide useful information in understanding the phytogeografic history of Neotropical vegetation.

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O objetivo deste estudo foi descrever a diversidade, composição e a similaridade da fauna de formigas entre sete remanescentes de Floresta Ombrófila Densa da Bacia Hidrográfica do Alto Tietê. Dois desses remanescentes pertencem à Unidades de Conservação, quatro estão sob proteção e um fragmento pertence à propriedade particular. Em cada área foram coletadas 50 m2 de serapilheira, que foram submetidas à extratores do tipo mini-Winkler, onde permaneceram por 48 h. Todas as coletas ocorreram no período chuvoso. No total foram registradas 11 subfamílias, 44 gêneros e 158 morfoespécies/espécies de formigas. As espécies mais frequentes em todas as áreas foram Pheidole sp.7, Solenopsis sp.1, Hypoponera sp.1 e Strumigenys denticulate. O maior valor de diversidade α foi registrado na unidade de conservação com composição florística de Mata Atlântica; o menor valor em florestas com influência antrópica. A variação na composição de espécies entre as áreas indica a substituição de espécies entre os remanescentes de Floresta Ombrófila Densa da Bacia Hidrográfica do Alto Tietê, o que sugere a importância da preservação dessas áreas para a conservação da diversidade regional da fauna de formigas.

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Pós-graduação em Ciências Biológicas (Genética) - IBB

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

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Far from the continental margin, drainage basins in Central Amazonia should be in topographic steady state; but they are not. Abandoned remnant fluvial valleys up to hundreds of square kilometers in size are observed throughout Amazonia, and are evidence of significant landscape reorganization. While major Late Miocene drainage shifts occurred due to initiation of the transcontinental Amazon River, local landscape change has remained active until today. Driven either by dynamic topography, tectonism, and/or climatic fluctuations, drainage captures in Amazonia provide a natural experiment for assessing the geomorphic response of low-slope basins to sudden, capture related base-level falls. This paper evaluates the timing of geomorphic change by examining a drainage capture event across the Baependi fault scarp involving the Cuieiras and TarumA-Mirim River basins northwest of the city of Manaus in Brazil. A system of capture-related knickpoints was generated by base-level fall following drainage capture; through numerical modeling of their initiation and propagation, the capture event is inferred to have occurred between the middle and late Pleistocene, consistent with other studies of landscape change in surrounding areas. In low-slope settings like the Amazon River basin, base-level fall can increase erosion rates by more than an order of magnitude, and moderate to large river basins can respond to episodes of base-level fall over timescales of tens to hundreds of thousands of years. Copyright (c) 2013 John Wiley & Sons, Ltd.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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In Southern Brazil, Aegla parana Schmitt, 1942 is characterized by a broad distribution throughout the Iguacu River basin, particularly between the southern state of Parana and the northern state of Santa Catarina, preferentially inhabiting streams with rocky substrates. Although there has been an increase in the number of studies about the population biology of Aeglidae, many aspects about the reproductive biology of A. parana are still unknown. Therefore, the present study aimed to investigate the size at sexual maturity, reproductive seasonality and recruitment of A. parana from November, 2008 to December, 2009, in a tributary of the Iguacu River located in Uniao da Vitoria, Parana, Brazil. Basic environmental factors were investigated to determine their influence on the reproductive cycle of this species. Gonadal stages were characterized macroscopically, and the presence or absence of embryos in females (ovigerous females) from monthly samples was recorded. The entire sample was composed of 436 males and 211 females. Although the smallest ovigerous female was 16.2 mm, the average size (carapace length, CL) at sexual maturity (CL50%) was calculated at 17.4 mm. The greatest percentage of females with developed (mature, near spawning) gonads stage was observed from January to June, 2009, while ovigerous females were recorded from April to July, 2009, after which the reproductive period ended. Recruitment occurred from October to December, 2009. The presence of ovigerous females was negatively correlated with temperature (Spearman, p < 0.05). Females carrying embryos were generally collected during periods of lower temperatures, whereas recruits entered the population during periods of higher temperatures, when food for them is more abundant in the region studied.

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

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The Constant Flux: Constant Sedimentation (CF:CS) and Constant Rate of Supply (CRS) of unsupported/excess Pb-210 models have been applied to a Pb-210 data set providing of eighteen sediments profiles sampled at four riverine systems occurring in Brazil, South America: Corumbatai River basin (S1=Site 1, Sao Paulo State), Atibaia River basin (S2=Site 2, Sao Paulo State), Ribeirao dos Bagres basin (S3=Site 3, Sao Paulo State) and Amazon River mouth. (S4=Site 4, Amapa State). These sites were chosen for a comparative evaluation of the performance of the CF:CS and CRS models due to their pronounced differences on the geographical location, geological context, soil composition, biodiversity, climate, rainfall, and water flow regime, among other variable aspects. However, all sediments cores exhibited a common denominator consisting on a database built from the use of the same techniques for acquiring the sediments major chemical composition (SiO2, Al2O3, Na2O, K2O, CaO, MgO, Fe2O3, MnO, P2O5, TiO2 and LOI-Loss on Ignition) and unsupported/excess 210Pb activity data. In terms of sedimentation rates, the performance of the CRS model was better than that of the CF:CS model as it yielded values more compatible with those expected from field evidences. Under the chronological point of view, the CRS model always provided ages within the permitted range of the Pb-210-method in the studied sites, whereas the CF:CS model predicted some values above 150 years. The SiO2 content decreased in accordance with the LOI increase in all cores analyzed and such inverse relationship was also tracked in the SiO2-LOI curves of historical trends. The SiO2-LOI concentration fluctuations in sites S1 and S3 also coincided with some Cu and Cr inputs in the drainage systems. (C) 2014 Elsevier Ltd. All rights reserved.

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The work is guided by the detailing of the Itajaí river basin, SC, rainfall dynamics at the annual, seasonal and monthly levels, allowing us to identify different responses that each location gives to the regional atmospheric circulation, particularly the rainfall. In this sense, we are aiming at approaching the concept of rhythm, which must be obtained at the daily level. The analysis at different climate scales was possible through isohyetal maps, trend lines, and Schroeder pluviographs. Moreover, we established the flow rate of the air masses by means of the Venn diagram. This data made it possible to assess the behavior of rains on that site and the reason why it is the stage of major flooding, as occurred in November 2008. The relatively mountainous topography combined with the frequent invasions of the Atlantic Polar Front, which often stop over the region, generate events of that magnitude, with high volumes accumulated in short periods of time. Such extreme events reinforce the idea of the search for the succession of types of weather to the detriment of averages that tend to abstract the reality

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This study aims to analyze the relationship between deforestation in the highlands of the São Francisco River Basin over the past 45 years due to agricultural activities and livestock , and the observed changes in the dynamics of the same river in the Pantanal of Mato Grosso , as sinuosity , discharge sediment , flow, points of erosion and morphological changes . It is observed that deforestation occurs in the plain and on the plateau , however with much more intensity in the latter, provided the extensive land use in the region . Thus, the study aims to contribute to a better understanding of the relationships between the uplands and flood plains . To achieve this goal will be used proper methods of geomorphological and geological sciences , with emphasis on the use of satellite imagery and hydrological data side . The research will include the following steps : I) literature review ; II) characterization geomorphological , geological , hydrological and climate , III) Dynamics of vegetation ; IV) Analysis of cause-effect relationships in the river system . Product analysis will suggest preventive measures to minimize the effects caused by the practices of use and occupation in the study area, as well as other regions suffer the same impacts

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Matrix can be defined as a portion of the landscape, that somewhere in time suffered intense human disturbance, such as decreasing of native vegetation. The matrix surrounding the forest fragments may create a certain resistance to the movements of individuals (RICKETTS, 2001). The Atlantic rainforest present in the Corumbataí river basin lost about 89% of its original vegetation, leading to a highly fragmented landscape (VALENTE e VETTORAZZI, 2005). In this context, this study aimed to evaluate the effect of the matrix and the characteristic capacity of two forest birds, Dysithamnus mentalis and Basileuterus flaveolus, moving around the landscape. With this aim, six fragments were selected, three with sugar cane matrix, three with Eucalyptus sp. matrix. The methodology utilized to evaluate the response of the birds was playback technique. First the vocalizations were carried out at the forest matrix boundary, in the edge, attracting individuals to the matrix. As the responses were generated, the playback was moved increasingly inside the matrix, observing the distances traveled by the species. The control trials were conducted inside the fragments, the playback was played at the edge and as the responses were observed, the vocalizations were carried out inside the fragment until the moment that individuals ceased answers. It could be observed that for individuals of D. mentalis the matrix generated a high resistance, because no individual entered the matrix. For B. flaveolus the average distance traveled in both matrices was 70 meters, indicating statistically high resistance of the sugar cane matrix and Eucalyptus sp. Considering the characteristics of different matrices, it was found that both matrices generate similar resistance in the movement of these species

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The expansion of urban in medium-sized citie, increase the importance of action planning and management of natural resources, among which water is the most important. Such action should include the integration of physical and man-made elements involved. In this context, it becomesimportant for watershed analysis and the use of geotecnologies. Thus, the objective was to demonstrate the contribution of the geo, as a tool for managing a river basin, allowing the integration of physical data and the analysis of anthropogenic environmental scenarios in urban areas. The area chosen, the basin of the Wenzel, is located in Rio Claro / SP, a city whose urbanization process has been intense and continuous. Thematic maps were generated from the physical environment: soil, slope and geological, as well as maps of land use. With regard to land use maps, these were drawn from the visual interpretation of material aerophotogrammetric, considering the years 1995 and 2010, performing an evolutionary analysis. It was observed that the area presents small variation in the physical and structural aspects, with lithological and geomorphological formation favoring the occurrence of floods, erosion and siltation. These processes are accelerated by the forms of land use, with intense urbanization during the period between 1995 and 2010, and poor preservation of permanent preservation areasand. In the floodplain areas there is a high waste disposal is the most notable environmental problem