50 resultados para Vegetation Division


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The present paper reports the assessment of the vegetation occupancy rate of the roadside, through analysis of aerial photographs. Using such value the potential of these areas to be employed as carbon (C) sinks was also assessed. Moreover, for the areas suitable for afforestation, the potential for carbon sequestration was estimated considering different species of vegetation, both native (scenario 1) and exotic (formed by Pinus sp. and Eucalyptus sp. - scenario 2). The study was carried out through GIS techniques and two regions were considered. A set of equations was used to estimate the rate of occupancy over the study areas, as well as amounts of fixed C under the above scenarios. The average occupancy rate was 0.06%. The simulation showed a higher potential for C sequestration in scenario 2, being the estimated amounts of CO(2) sequestered from the atmosphere per km of roadside: 131 tons of CO(2) km(-1) of highway to native species and 655 tons of CO(2) km(-1) of highway for exotic species (over period of 10 years for both estimates). If we consider the whole road network of the São Paulo State (approximately 190 000 km) and that a considerable part of this road work is suitable to receive this kind of service, it is possible to predict the very high potential for C sequestration if managers and planners consider roadside as area for afforestation.

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Surveys were carried out in terra firme' forest, successional forest, buritirana' (palm vegetation) and shrub canga' (savanna). Extrafloral nectaries (EFNs) were present in 30 plant species belonging to 22 genera and 14 families. Nectary species represented 17.6-53.3% of the species samples in different areas, with local abundances varying from 19.1-50.0%. The percentage of species with EFNs was greater in the flora of the shrub canga than in the terra firme and successional forests. Nectary plants were more abundant in the shrub canga and successional forest. The high abundance of EFNs may be the result of intense foraging activity by ants on plants, leading to the formation of facultative mutualism. -from Authors

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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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The behavioral division of labor between queens and workers of E. edentatum was investigated under laboratory conditions. Each behavioral category of both castes was described by direct observation of the ants in the colonies. The spatial position and the behavior of each individual were recorded. A colony ethogram was constructed to determine comparatively the behavioral repertory of the 2 castes. Most of the members of the colonies, including the queens, occupied the 2nd chamber, which also contained the immature stages. Forty-two behavioral categories were recorded for the workers, and 28 for the queens. The comparison of the behavioral repertory of the 2 castes revealed that ovipositing a fecundated egg is an exclusive behavior of the queens, while the workers showed 15 exclusive behaviors. Queens were never seen foraging out of the nest. Twelve behaviors were common for both castes. Polygynic colonies have only 1 female with full-developed ovaries, which is the main egg layer of the group, a feature defining the social organization of colonies of E. edentatum as a functional monogyny.

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The purpose of this investigation was to evaluate the dentoalveolar and skeletal cephalometric changes produced by the Fränkel appliance in individuals with a Class II, division 1 malocclusion. Lateral cephalograms of 44 patients of both sexes were divided in two groups of 22 each. The control group was comprised of untreated Class II children with an initial mean age of eight years and seven months who were followed without treatment for a period of 13 months. The Fränkel group had an initial mean age of nine years and was treated for a mean period of 17 months. Lateral cephalometric headfilms of each patient were obtained at the beginning and end of treatment. The Fränkel appliance produced no significant changes in maxillary growth during the evaluation period, while a statistically significant increase in mandibular length was observed. The maxillomandibular relationship improved mostly because of an increase in mandibular length. In addition, there were no statistically significant differences in the craniofacial growth direction between the Fränkel and the control group, both showing a slight downward rotation of the palatal plane. The Fränkel appliance produced a labial tipping of the lower incisors and a lingual inclination of the upper incisors as well as a significant increase in mandibular posterior dentoalveolar height. It was concluded that the main effects of the Fränkel appliance during this time period were mostly dentoalveolar with a smaller but significant skeletal mandibular effect.

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Among 89 plants species growing in a subtropical dry forest fragment located in Botucatu, State of São Paulo, Brazil, 35 species were cut by Atta sexdens, representing 39.34% of the current plants existing in this area. A. sexdens L., 1758 (Hymenoptera: Formicidae) has a selective preference for the following species: Alchornea triplinervia, Faramea cyanea, Cariniana estrellensis and Casearea obliqua, with the first being the most cut species. The frequency and absolute densities of the plant families and species significantly influence the selection process. When comparing the absolute frequency regarding the 10 most cut plant species and the cutting frequency, significant data were obtained only for the euphorbiaceous A. triplinervia species, proving the preference of A. sexdens for this species in particular. These interactions are discussed based on ecological and management factors in agro-ecosystems.

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The mining process promotes land modification and complete landscape alteration. Those alterations in the surface are shown more obviously in the aesthetical aspect as the visual elements of form, texture, climbs, complexity and color which composes the landscape. As a consequence, mining has impacts on the topography, in the soil, in the vegetation and in the area's drainage, with a direct influence on the enterprise. A quite common problem in the recovery of degraded areas in mineral exploration is the compaction of the soil due to the intense traffic of machines and earth movement. The most common problem of the compaction of a degraded surface is an increase of the mechanical resistance to the penetration of plant roots, a reduction of the aeration, an alteration of the flow of water and heat, also in the availability of water and nutrients. Thus, the present work had the basic objective of diagnosing the compaction of an area degraded by mining in a spacial way, through the mechanical resistance and the penetration, to guide the future subsoiling in the area requiring recovery. Through the studies, it was concluded that the krigagem method in agreement with the space variation allows the division of the area under study into sub areas facilitating a future work to reduce costs and unnecessary interference to the atmosphere. The method was shown to be quite appropriate and it can be used in the diagnosis of compaction in a degraded area by mining, foreseeing the subsoiling requirement.

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Methods based on visual estimation still is the most widely used analysis of the distances that is covered by soccer players during matches, and most description available in the literature were obtained using such an approach. Recently, systems based on computer vision techniques have appeared and the very first results are available for comparisons. The aim of the present study was to analyse the distances covered by Brazilian soccer players and compare the results to the European players', both data measured by automatic tracking system. Four regular Brazilian First Division Championship matches between different teams were filmed. Applying a previously developed automatic tracking system (DVideo, Campinas, Brazil), the results of 55 outline players participated in the whole game (n = 55) are presented. The results of mean distances covered, standard deviations (s) and coefficient of variation (cv) after 90 minutes were 10,012 m, s = 1,024 m and cv = 10.2%, respectively. The results of three-way ANOVA according to playing positions, showed that the distances covered by external defender (10642 ± 663 m), central midfielders (10476 ± 702 m) and external midfielders (10598 ± 890 m) were greater than forwards (9612 ± 772 m) and forwards covered greater distances than central defenders (9029 ± 860 m). The greater distances were covered in standing, walking, or jogging, 5537 ± 263 m, followed by moderate-speed running, 1731 ± 399 m; low speed running, 1615 ± 351 m; high-speed running, 691 ± 190 m and sprinting, 437 ± 171 m. Mean distance covered in the first half was 5,173 m (s = 394 m, cv = 7.6%) highly significant greater (p < 0.001) than the mean value 4,808 m (s = 375 m, cv = 7.8%) in the second half. A minute-by-minute analysis revealed that after eight minutes of the second half, player performance has already decreased and this reduction is maintained throughout the second half. ©Journal of Sports Science and Medicine (2007).

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We describe and begin to evaluate a parameterization to include the vertical transport of hot gases and particles emitted from biomass burning in low resolution atmospheric-chemistry transport models. This sub-grid transport mechanism is simulated by embedding a 1-D cloud-resolving model with appropriate lower boundary conditions in each column of the 3-D host model. Through assimilation of remote sensing fire products, we recognize which columns have fires. Using a land use dataset appropriate fire properties are selected. The host model provides the environmental conditions, allowing the plume rise to be simulated explicitly. The derived height of the plume is then used in the source emission field of the host model to determine the effective injection height, releasing the material emitted during the flaming phase at this height. Model results are compared with CO aircraft profiles from an Amazon basin field campaign and with satellite data, showing the huge impact that this mechanism has on model performance. We also show the relative role of each main vertical transport mechanisms, shallow and deep moist convection and the pyro-convection (dry or moist) induced by vegetation fires, on the distribution of biomass burning CO emissions in the troposphere.

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Four colonies of the ant Pachycondyla striata were used to analyze the specie behavioral repertoire. Forty-six behavioral acts were recorded in laboratory. Here, we present the record the division of labor between the castes and the temporal polyethism of monomorphic workers. The queens carried out many of the behavioral traits recorded in this work however; they performed them less frequently compared to the worker. The workers activity involved chasing and feeding on fresh insects and usingthem to nourish larvae besides laying eggs in the C-posture, an activity also performed by queens, which is similar to that of wasps of the subfamily Stenogastrinae. The young workers were involved in activities of brood care, sexuate care, and nest maintenance, and the older workers were involved in defense, exploration, and foraging. © 2012 Adolfo da Silva-Melo and Edilberto Giannotti.

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The water column overlying the submerged aquatic vegetation (SAV) canopy presents difficulties when using remote sensing images for mapping such vegetation. Inherent and apparent water optical properties and its optically active components, which are commonly present in natural waters, in addition to the water column height over the canopy, and plant characteristics are some of the factors that affect the signal from SAV mainly due to its strong energy absorption in the near-infrared. By considering these interferences, a hypothesis was developed that the vegetation signal is better conserved and less absorbed by the water column in certain intervals of the visible region of the spectrum; as a consequence, it is possible to distinguish the SAV signal. To distinguish the signal from SAV, two types of classification approaches were selected. Both of these methods consider the hemispherical-conical reflectance factor (HCRF) spectrum shape, although one type was supervised and the other one was not. The first method adopts cluster analysis and uses the parameters of the band (absorption, asymmetry, height and width) obtained by continuum removal as the input of the classification. The spectral angle mapper (SAM) was adopted as the supervised classification approach. Both approaches tested different wavelength intervals in the visible and near-infrared spectra. It was demonstrated that the 585 to 685-nm interval, corresponding to the green, yellow and red wavelength bands, offered the best results in both classification approaches. However, SAM classification showed better results relative to cluster analysis and correctly separated all spectral curves with or without SAV. Based on this research, it can be concluded that it is possible to discriminate areas with and without SAV using remote sensing. © 2013 by the authors; licensee MDPI, Basel, Switzerland.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The correlation between vegetation patterns (species distribution and richness) and altitudinal variation has been widely reported for tropical forests, thereby providing theoretical basis for biodiversity conservation. However, this relationship may have been oversimplified, as many other factors may influence vegetation patterns, such as disturbances, topography and geographic distance. Considering these other factors, our primary question was: is there a vegetation pattern associated with substantial altitudinal variation (10-1,093 m a.s.l.) in the Atlantic Rainforest-a top hotspot for biodiversity conservation-and, if so, what are the main factors driving this pattern? We addressed this question by sampling 11 1-ha plots, applying multivariate methods, correlations and variance partitioning. The Restinga (forest on sandbanks along the coastal plains of Brazil) and a lowland area that was selectively logged 40 years ago were floristically isolated from the other plots. The maximum species richness (>200 spp. per hectare) occurred at approximately 350 m a.s.l. (submontane forest). Gaps, multiple stemmed trees, average elevation and the standard deviation of the slope significantly affected the vegetation pattern. Spatial proximity also influenced the vegetation pattern as a structuring environmental variable or via dispersal constraints. Our results clarify, for the first time, the key variables that drive species distribution and richness across a large altitudinal range within the Atlantic Rainforest. © 2013 Springer Science+Business Media Dordrecht.

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In fluvial systems, the relationship between a dominant variable (e.g. flood pulse) and its dependent ones (e.g. riparian vegetation) is called connectivity. This paper analyzes the connectivity elements and processes controlling riparian vegetation for a reach of the upper Paraná River (Brazil) and estimates the future changes in channel-vegetation relationship as a consequence of the managing of a large dam. The studied reach is situated 30km downstream from the Porto Primavera Dam (construction finished in 1999). Through aerial photography (1:25,000, 1996), RGB-CBERS satellite imagery and a previous field botany survey it was possible to elaborate a map with the five major morpho-vegetation units: 1) Tree-dominated natural levee, 2) Shrubby upper floodplain, 3) Shrub-herbaceous mid floodplain, 4) Grass-herbaceous lower floodplain and 5) Shrub-herbaceous flood runoff channel units. By use of a detailed topographic survey and statistical tools each morpho-vegetation type was analyzed according to its connectivity parameters (frequency, recurrence, permanence, seasonality, potamophase, limnophase and FCQ index) in the pre- and post-dam closure periods of the historical series. Data showed that most of the morpho-vegetation units were predicted to present changes in connectivity parameters values after dam closing and the new regime could affect, in different intensity, the river ecology and particularly the riparian vegetation. The methods used in this study can be useful for dam impact studies in other South American tropical rivers. © 2012 Elsevier Ltd.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)