956 resultados para Floresta de Transição Amazônia-Cerrado


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Vinasse, a liquor effluent from the alcohol and sugar making industry, was applied annually for twelve years to medium-textured red-yellow latosols under cerrado vegetation sensu stricto, to study the environmental impacts on the biotic and abiotic factors. Four plots were established of which two acted as control and the other two received annual doses of vinasse. The studies were begun in 1980 when the first annual dose of 20 L m-2 year-1 was added to the soil without removing the top scrub layer. Theses doses were added to the soil until 1983, but in 1984 the doses were increased to 50 L m-2 year-1 and used until 1991. Soil samples were taken at a depth of 15 cm every three months from 1987 to 1991. Twenty seven environmental variables in the vinasse-treated and untreated plots were studied. These factors consisted of different enzymatic activities, a number of filamentous fungi, bacteria, actinomycetes and other micro-organisms, nutrients and some micro-climatic factors. The results obtained were statistically analyzed using the Tukey test, Pearson correlation and variance test methods with replicates and three factors. Matrices were determined using the correlation coefficient method and were compared with those of earlier published studies in the same area. The comparison of the results helped characterize changes in the environmental factors studied and in the correlation between them, after using annual cumulative doses of vinasse. Positive effects were observed only for the first six years of this application but vinasse had negative effects after the seventh year. It is concluded that medium-textured red-yellow latosols cannot be treated with vinasse for proloned periods.

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Bioactivity-guided fractionation of several bioactive extracts obtained from Cerrado and Atlantic Forest plant species led to the isolation of potent DNA-damaging piperidine 1-5 and guanidine alkaloids 6-9 from Cassia leptophylla and Pterogyne nitens respectively, two common Leguminosae from Atlantic Forest. By means of biotechnological approach on Maytenus aquifolium, a species from Cerrado, moderate DNA-damaging sesquiterpene pyridine alkaloid 10-11 was isolated. Bioassay-guided fractionation on Casearia sylvestris, a medicinal plant species found in Cerrado and Atlantic Forest, led to the isolation of clerodane diterpenes 12-13 which showed effect on DNA. In addition, we have reported several interesting potent antifungal iridoids: 1β-hydroxy-dihydrocornin (14), 1α-hydroxy-dihydrocornin (15), α-gardiol (16), β-gardiol (17), plumericin (18), isoplumericin (19), 11-O-trans-caffeoylteucrein (20); ester derivative: 2-methyl-4-hydroxy-butyl-caffeoate (21), amide N-[7-(3'.4'-methylenedioxyphenyl)-2Z, 4Z-heptadienoyl] pyrrolidine (22) and triterpene viburgenin (23).

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The objective of the present paper was to study the structure of a semi-deciduous forest. The main purpose was to verify if the floristic composition and/or structure is influenced by the mosaic developmental phase. The study has been done in 200 plots, each one measuring 10 × 10 m, forming a grid of 200m × 100 m in the center of the forest fragment. In to separate the study area in units representing different phases of forest mosaic (gap, construction and mature), the plots were classified by cluster analysis based on structural traits. The species with the highest influence the community structure were Aspidosperma polyneuron, Trichilia claussenii and Trichilia catigua.Gap, construction and mature phases presented different patterns in spite of the three species influence.

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In order to evaluate growth characteristics, adaptability, biomass production, nutrient recycling, nutrient distribution and the ability to regenerate degraded land, a trial using four multipurpose tree species (Leucaena leucocephala, Leucaena diversifolia, Acacia melanoxylon and Mimosa scabrella) was undertaken over two years in a distrophic red yellow latosol (oxisol) following a randomized block experimental design with four replications. At the age of two years, A. melanoxylon and L. diversifolia were the tallest species (5.25 and 4.97 m, respectively) and A. melanoxylon and M. scabrella had the largest diameters at 20 cm from tree base. Mimosa scabrella and A. melanoxylon had the highest dry matter production and quantity of nutrients in the above ground biomass. In all species, the highest nutrient contents were found in the leaves, followed by branches and stems. From all species, the highest Nutrient Utilization Efficiency Indexes were obtained for sulphur, phosphorous, and magnesium; L. diversifolia was the most efficient for nitrogen, potassium, calcium, sulphur, and manganese, while A. melanoxylon was the most efficient for phosphorus, magnesium, boron, iron, and zinc. Litter production levels over a three month period were as follows: M. scabrella > A. melanoxylon > L. diversifolia > L. leucocephala. Litter nutrient content was higher in M. scabrella than in the other species.

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Fruits have been considered an important feeding resource used not only by frugivorous birds, but also by omnivore and some insectivore species. In the present paper we are reporting the behavior of birds consuming fruits of Davilla rugosa (Dilleniaceae). Handling behavior and visits frequency were analyzed in order to infer about the potential ornithochoric seed dispersal. Focal observations were carried out from October to December 1999 in a cerrado fragment located in São Paulo State, Southeastern Brazil (21°58′S, 47°52′W). In 60 h of field work we recorded 241 visits of 13 passerine bird species consuming the fruits. The mean number of visits per hour and the standard deviation were 4.01 ± 4.88. All of the species were considered potential seed dispersers, since no pulp mashers or seed predators were observed. No temporal difference in visit frequency was found when all of the species were analyzed together or when they were individually considered. Generalist species were responsible for 68.5% of the visits, followed by frugivorous (22.82%) and insectivorous (8.71%). The main potential seed dispersers were Elaenia spp. (Tyrannidae), Tangara cayana (Emberizidae), Empidonomus varius (Tyrannidae), Turdus leucomelas (Muscicapidae) and Vireo chivi (Vireonidae). The high visit frequency observed suggests that D. rugosa fruits may be an important feeding resource for birds in the cerrado ecosystem, in the manner that this plant can be considered in management plans which intent to maintain or rescue bird communities.

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Constrictotermes cyphergaster builds arboreal nests in Cerrado sensu stricto of Brazil; inquiline termites and termitophiles frequently inhabit their nests. Measurements of the nests and the support trees (nest width and diameter; tree trunk circumference and inclination), colony size of C. cyphergaster and of Inquilinitermes and number of termitophiles were studied at the Parque Estadual da Serra de Caldas Novas. These variables were subjected to a Principal Component Analysis, producing four principal components. The first principal component refers to a multidimensional axis of nest size, encompassing variables related to nest and colony size, such as abundance per caste of C. cyphergaster and I. microcerus, number of termitophile species and the measurements of the nest. The number of soldiers and workers of C. cyphergaster and soldiers of Inquilinitermes increased proportionally to the axis of nest size, while the number of Inquilinitermes workers increased more quickly then the increase in the nest size. Both Inquilinitermes occurred mainly in larger nests. Almost half of the nests (47,5%) were inhabited by I. microcerus and 10% by I. fur.

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We present the results of the first bat inventory at the 'Serra das Araras' Ecological Station, MT, in the northwestern portion of the Cerrado domain. We captured bats using the traditional ground-level mist netting and, occasionally, high nets placed 3 m above the ground, and hand nets for hoosting bats. We recorded 23 species distributed in six families (Emballonuridae, Noctilionidae, Mormoopidae, Phyllostomidae, Molossidae, and Vespertilionidae), including Artibeus gnomus and A. anderseni, which had never been recorded in the Cerrado domain. © 2004 Instituto de Ciências Biológicas - UFMG.

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The objective of this study was determine the spatial distribution of genotypes of Terminalia argentea Mart et Suce. (Capitão-do-campo) in a natural population, aiming to outline strategy to genetic conservation in situ and ex situ. The population (Terminalia argentea) is located in an area of cerrado on the Teaching and Research Farm of FEIS / UNESP. It was sampled seeds in 30 trees to determine the biochemistry and technological traits. The trees were also located per GPS apparatus, with objective of obtaining geographic coordinate and to analysis the genotype spatial structure from I Moran Index. The analysis of spatial autocorrelations, from I Moran index, indicated the tendency of a larger structure among trees near spatially. In another hand, trees distant spatially showed smaller similarity. The spatial structure was more visible in a ray of 353m.

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The present work evaluated urban forest indicators, acquired through airborne high-resolution multiespectral images, on the quality of the urban design and its vegetative fraction, in special its trees, in nine neighborhoods of Piracicaba, SP. There were made supervised classifications for characterization of intra-urban elements and the proportions obtained, as exposed soil, tree cover, lawns, asphalt, concrete pavements and roofs. They were studied for the measurement of the urban forest in each place. These variables were related to each other, as well as with the independent variables: population density, people with more than fifteen years of study and family heads with income above twenty minimum wages, obtained through population census. Through the analysis of linear regression variables were identified for intra-urban areas evaluation. Correlations were made and linear regressions among the data obtained from the image and among the proposed indicators. Negative correlations were obtained among population density and arboreal covering and the evaluated indices, in accordance with the predicted in the literature. Composite indicators are proposed, as: the proportion between arboreous space on waterproof space (PAW) and the proportion between arboreous space on building space (PAB). It is concluded by the possibility of the use of those indicators for evaluation of the urban forest and definition of priorities in the execution of ordinances to the improvement of the urban forestry, being prioritized the application of resources in the most lacking neighborhoods.

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The purpose of this study was to realize a floristic survey in riparian forest remains of the Upper Paraná River, under domain of the submontane seasonal semideciduous forest, located in Porto Rico, Paraná, Brazil (53°19'3 W e 22°47'37 S). Within and in the neighborhood of 10.000 m2 area (100 m × 100 m), 165 species were surveyed, in 124 genera and 60 families, distributed in arboreous, shrubs, herbs, climbers and hemiparasites. Leguminosae, Myrtaceae, Poaceae, Rubiaceae, and Bignoniaceae were the families with the highest species' richness, showing together 33.33%, and the genera more representative were Eugenia, Casearia, Guarea, Inga, Panicum, and Solanum, with 12.73% of the species. Though the perturbations verified in the forest remains, eight species were rare for this type of vegetation and 12 were listed as fishes natural food.