83 resultados para Moors (Wetlands)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The marsh deer is the largest neotropical cervid with morphological and ecological adaptations to wetlands and riparian habitats. Historically, this now endangered species occupied habitats along the major river basins in South America, ranging from southern Amazonia into northern Argentina to the Parana river delta. This particularly close association with wetlands makes marsh deer an excellent species for studying the effects of Pleistocene climatic changes on their demographic and phylogeographic patterns. We examined mitochondrial DNA variation in 127 marsh deer from 4 areas distributed throughout the Rio de]a Plata basin. We found 17 haplotypes in marsh deer from Brazil, Bolivia and Argentina that differed by 1-8 substitutions in a 601 bp fragment of mitochondrial control region sequence, and 486 bp of cytochrome b revealed only 3 variable sites that defined 4 haplotypes. Phylogeny and distribution of control region haplotypes suggest that populations close to the Pantanal area in central Brazil underwent a rapid population expansion and that this occurred approximately 28,000-25,000 years BP. Paleoclimatic data from this period suggests that there was a dramatic increase for precipitation in the medium latitudes in South America and these conditions may have fostered marsh deer's population growth.
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The brown-nosed coati (Nasua nasua) is a carnivorous species found in all the Brazilian biomes, some of which are endangered areas. The aim of this work was to determine the habitat use and selection, home range and core area of N. nasua in the Cerrado biome, central region of Tocantins, Brazil. The study was carried out in an area of approximately 20 000ha from May 2000 to July 2002. A total of seven box traps were placed in the area for 13 months, three of 11 captured animals were followed and monitored by radio-tracking during 13 months. The monitoring was conducted once a day, three times a week using a car and walking through the study area (radio-tracking and visual contact). The results demonstrate that these three males used more frequently the gallery forest formation, followed by cerrado and wetlands. The use of gallery forest by these animals indicated an habitat selection (Proportion test, z=12.98, p< 0.01). Besides, adult males used the gallery forest more frequently (Fisher's exact test, p<0.01) and wetlands less frequently (Fisher's exact test, p<0.01) than juvenile males, without significant differences between animal ages for cerrado percentage of habitat use. Besides, results also showed a gallery forest selection by adult (Proportion test z= 13.62, p<0.01) and juvenile (Proportion test z=2.68, p<0.01) males, and a wetland selection by the juvenile male (Proportion test z=3.90, p<0.01). The home ranges varied from 2.20 to 7.55km2 for the Minimum Convex Polygon 100% (MCP 100%) and from 4.38 to 13.32km2 for the Harmonic Mean 95% (HM 95%). The smallest home range overlap occurred between the adult males (Nm1 and Nm3), and the greatest between the juvenile Njm2 and the adult Nm1. The average of the core area (HM 75%) for the three monitored animals represented 21.29% of the home range calculated with HM 95%. No overlap between core areas was observed for adult males, but, it was an overlap between the core area of the juvenile male and its band with that of the two adult males. The present study provides new data on core area size and frequency habitat use by adult and juvenile males of N. nasua in the Brazilian Cerrado, that may support conservation efforts. Rev. Biol. Trop. 58 (3): 1069-1077. Epub 2010 September 01.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The aim of this research was the development of a procedure to measure biological kinetics of organic matter oxidation and nitrification in constructed wetland, by using respirometric techniques. Columns simulating cores of vertical subsurface flow systems were investigated. The oxygen uptake rate (OUR) of the columns was calculated on the basis of the difference of DO concentrations measured continuously at the top and at the bottom of the column. From the respirogram, the following kinetic parameters have been evaluated: maximum rate of oxidation of readily biodegradable COD, maximum rate of nitrification, endogenous respiration of the biomass grown inside the bed. In order to improve the interpretation of the respirograms, additional respirometric tests were carried out on the wetland columns by using pure substrates, such as acetate (carbon source) and ammonium (substrate for nitrification). The kinetic parameters obtained from respirograms can be useful for control and design of constructed wetlands or for improving nutrient and carbon mass balances.
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The South American water snake Helicops leopardinus is very abundant in the Pantanal wetlands of Central Brazil. We studied the biology of this species based on specimens collected by local workers in the Paraguay River. Females attained greater body lengths and had larger heads than males, but the latter had longer tails. Helicops leopardinus fed on a wide variety of fishes (70% of the total prey items) and frogs, with fishes of the order Gymnotiformes (33.34%) and frogs of the family Hylidae (23.34%) representing the most common prey items. There was relatively lows diet overlap between the sexes and between juveniles and adults. Mean litter size was 6.6 and ranged from 4-11. The reproductive cycle was seasonal, with birth occurring late in the wet season (simultaneous with the flooding of the Paraguay River), facilitating dispersal of young snakes by floating vegetation. Floating vegetation may be a critical habitat for H. leopardinus, and management plans for their maintenance need to be developed.
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Total phosphorus concentrations in the sediment of a cascade of 8 reservoirs located in the Paranapanema River (SE, Brazil) were analysed during two consecutive seasonal periods (2000 and 200 1). The reservoirs of Jurumirim, Chavantes, Salto Grande, Canoas 11, Canoas 1, Capivara, Taquarucu and Rosana were built during the last five decades with the purpose of hydroelectric generation. The sampling points were distributed along a 700 km of river stretch in 19 stations distributed in the river-reservoirs zones and main tributaries as well as in 5 stations representing the adjacent wetlands. The nutrient concentration was determined in samples from surface layers of sediment. Temporal and spatial changes were observed for both years. Three different areas could be identified along the river, considering not only Tot-P variations but also others physical and chemical characteristics such as organic matter concentration, nitrogen concentration of sediment and 02, pH, conductivity and Eh measured in the bottom layer of the water column. Higher values of Tot-P were found in the middle and lower region of the Paranapanema basin (maximum value of 1.96 mg g(-1) in Tibagi River in October/2001). Agricultural practices and cattle raising are the main external sources of nutrient in these regions. Superficial or sub-superficial watershed drainage and tributaries entrances are important nutrient contributors, leading to an increasing accumulation of nutrient in the sediment. This process seems to be especially important in the middle region of the Paranapanema Valley, were the values of Tot-P were higher comparing to the other areas.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Os cerradões no Pantanal ocorrem em áreas não inundáveis da planície e são importantes para a economia regional. Das áreas de cerradão são retiradas madeiras para construção de cercas, currais e galpões. Apesar da grande importância dos recursos vegetais do cerradão, existem poucas informações para embasar sua conservação e uso sustentável. Este trabalho teve como objetivos estudar a abundância, a distribuição das espécies arbóreas e correlações com a fertilidade do solo em áreas de cerradão (savana florestada) do Pantanal Sul Mato-grossense. Foram estudadas seis áreas de cerradão na sub-região da Nhecolândia, por meio de 30 pontos quadrantes, totalizando 120 árvores amostradas, com circunferência a altura do peito (CAP) > 15 cm, em cada área. As comparações florísticas, de abundância das espécies e de fertilidade do solo, foram efetuadas por análises de componentes principais (PCA). As áreas mostraram-se heterogêneas, apresentando diferentes níveis de fertilidade do solo, estrutura e composição da vegetação. Dois cerradões foram agrupados em termos de fertilidade do solo e de estrutura da vegetação, apresentando muitas árvores de Qualea grandiflora Mart., espécie que ocorreu associada a solos com maiores teores de fósforo. Outros dois cerradões apresentaram composição florística mais semelhante que os demais, apesar de ocorrerem em solos com diferentes níveis de fertilidade, indicando perturbação antrópica.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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In the Pantanal wetlands of Central Brazil, the endangered hyacinth macaw (Anodorhynchus hyacinthinus), the largest psitacid in the world, makes its nest almost exclusively in natural hollows found in the manduvi tree (Sterculia apetala). The recruitment of manduvis greatly depends on the seed dispersal services provided by the toco toucan (Ramphastos toco), responsible for 83.3% of the seed dispersal. The toco toucan, however, is responsible for about 53% of the preyed eggs, resulting in a case of conflicting ecological pressures in which the reproduction of the hyacinth macaw is indirectly dependent on the seed dispersal services of its nest predator. The case illustrates the intricacies of biotic interactions in species-rich environments where species may be tied by indirect, subtle ecological links which conservationists should be aware of. (c) 2008 Elsevier Ltd. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Informações sobre o ciclo reprodutivo de espécies exploradas pela pesca são imprescindíveis para o seu manejo adequado. O tamanho de início da atividade reprodutiva do Pinirampus pirinampu (Spix, 1829) foi determinado. Os exemplares foram capturados em setembro, outubro e dezembro de 1997 e fevereiro e março de 1998. O estádio de desenvolvimento gonadal foi identificado macroscopicamente. O índice gonadossomático médio (IGS), calculado mensalmente, foi utilizado como indicador da época de desova. Para determinação do comprimento da primeira maturação gonadal agruparam-se, separadamente, machos e fêmeas por classes de comprimento em imaturos e adultos. Os resultados referentes aos indivíduos adultos foram lançados em gráficos e a mediana correspondeu à estimativa do comprimento no qual 50% dos indivíduos atingem a maturidade (L50). Foi também determinado o L100, estimativa do comprimento em que todos os indivíduos estão aptos à reprodução. Machos e fêmeas em processo de maturação gonadal foram encontrados a partir de outubro, com maior freqüência em fevereiro, e, somente a partir deste mês, foram encontrados indivíduos com gônadas esvaziadas. O índice gonadossomático mostrou que a partir de setembro inicia-se o processo de desenvolvimento gonadal, com seu valor máximo em fevereiro. O L50 para fêmeas foi 574 mm e para machos foi 536 mm. O L100 para fêmeas foi 590 mm e para os machos, 580 mm.