994 resultados para Atlantic-Mediterranean relationships


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Sedentary consumers play an important role on populations of prey and, hence, their patterns of abundance, distribution and coexistence on shores are important to evaluate their potential influence on ecosystem dynamics. Here, we aimed to describe their spatio-temporal distribution and abundance in relation to wave exposure in the intertidal rocky shores of the south-west Atlantic to provide a basis for further understanding of ecological processes in this system. The abundance and composition of the functional groups of sessile organisms and sedentary consumers were taken by sampling the intertidal of sheltered and moderately exposed shores during a period of one year. The sublittoral fringe of sheltered areas was dominated by macroalgae, while the low midlittoral was dominated by bare rock and barnacles. In contrast, filter-feeding animals prevailed at exposed shores, probably explaining the higher abundance of the predator Stramonita haemastoma at these locations. Limpets were more abundant at the midlittoral zone of all shores while sea urchins were exclusively found at the sublittoral fringe of moderately exposed shores, therefore, adding grazing pressure on these areas. The results showed patterns of coexistence, distribution and abundance of those organisms in this subtropical area, presumably as a result of wave action, competition and prey availability. It also brought insights on the influence of top-down and bottom-up processes in this area.

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Morphological and molecular analyses have proven to be complementary tools of taxonomic information for the redescription of the ctenostome bryozoans Amathia brasiliensis Busk, 1886 and Amathia distans Busk, 1886. The two species, originally described from material collected by the `Challenger` expedition but synonymized by later authors, now have their status fixed by means of the selection of lectotypes, morphological observations and analyses of DNA sequences described here. The morphological characters allowing the identification of living and/or preserved specimens are (1) A. brasiliensis: whitish-pale pigment spots in the frontal surface of stolons and zooids, and a wide stolon with biserial zooid clusters growing in clockwise and anti-clockwise spirals along it, the spirality direction being maintained from maternal to daughter stolons; and (2) A. distans: bright yellow pigment spots in stolonal and zooidal surfaces including lophophores, and a slender stolon, thickly cuticularized, with biserial zooid clusters growing in clockwise and anti-clockwise spirals along it and the spirality direction not maintained from maternal to daughter stolons. Pairwise comparisons of DNA sequences of the mitochondrial genes cytochrome c oxidase subunit I and large ribosomal RNA subunit revealed deep genetic divergence between A. brasiliensis and A. distans. Finally, analyses of those sequences within a Bayesian phylogenetic context recovered their genealogical species status.

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The present study investigates the effects of drill cutting discharges on the structure of meiofauna communities in an area of the shelf break at Campos Basin, Southeast Brazil. Drilling activities were operated, in a first phase, with water-based fluid and, in a second phase, with synthetic fluid paraffin-based (NAF-III). A total of 135 samples taken at a pre-drilling situation (MS1) and two post-drilling moments (MS2 and MS3-3 and 22 months post-drilling, respectively) were analyzed. Effects on meiofauna were dependent on two main factors: 1-the impact received during drilling operation, if water-based or synthetic/water-based drilling fluid and 2-the background state, if it already presented signs of previous drilling activities or not. Based on univariate and multivariate analysis, there were evidences that the most affected area after drilling was those under the influence of synthetic-based fluid and that already had signs of previous drillings activities. The region impacted only by water-based fluid was less affected and the only one that completely recovered after 22 months. Nematodes and copepods had different responses to the impact. While copepods flourish in the impacted area and recovered 22 months after drilling, nematodes were adversely affected shortly after drilling and the community structure only recovered where hydrocarbons had been depleted.

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This paper describes four new species of the bryozoan genus Beania from the Brazilian coast. Two of them have been previously recorded in the western Atlantic as Beania hirtissima (Heller, 1867) and Beania mirabilis Johnston, 1840, respectively; they are redescribed here as Beania americana n. sp. and Beania mirabilissima n. sp. Two reticulate species, Beania correiae n. sp. and Beania metrii n. sp., are newly described. Descriptions of four other species of Beania from the region are also included: Beania australis Busk, 1852, Beania cupulariensis Osburn, 1914, Beania klugei Cook, 1968 and Beania maxilladentata Ramalho, Muricy & Taylor, 2010.

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Live aboveground biomass (AGB) is an important source of uncertainty in the carbon balance from the tropical regions in part due scarcity of reliable estimates of live AGB and its variation across landscapes and forest types. Studies of forest structure and biomass stocks of Neotropical forests are biased toward Amazonian and Central American sites. In particular, standardized estimates of aboveground biomass stocks for the Brazilian Atlantic forest are rarely available. Notwithstanding the role of environmental variables that control the distribution and abundance of biomass in tropical lowland forests has been the subject of considerable research, the effect of short, steep elevational gradients on tropical forest structure and carbon dynamics is not well known. In order to evaluate forest structure and live AGB variation along an elevational gradient (0-1100 m a.s.l.) of coastal Atlantic Forest in SE Brazil, we carried out a standard census of woody stems >= 4.8 cm dbh in 13 1-ha permanent plots established on four different sites in 2006-2007. Live AGB ranged from 166.3 Mg ha(-1) (bootstrapped 95% CI: 1444,187.0) to 283.2 Mg ha(-1) (bootstrapped 95% CI: 253.0,325.2) and increased with elevation. We found that local-scale topographic variation associated with elevation influences the distribution of trees >50 cm dbh and total live AGB. Across all elevations, we found more stems (64-75%) with limited crown illumination but the largest proportion of the live AGB (68-85%) was stored in stems with highly illuminated or fully exposed crowns. Topography, disturbance and associated changes in light and nutrient supply probably control biomass distribution along this short but representative elevational gradient. Our findings also showed that intact Atlantic forest sites stored substantial amounts of carbon aboveground. The live tree AGB of the stands was found to be lower than Central Amazonian forests, but within the range of Neotropical forests, in particular when compared to Central American forests. Our comparative data suggests that differences in live tree AGB among Neotropical forests are probably related to the heterogeneous distribution of large and medium-sized diameter trees within forests and how the live biomass is partitioned among those size classes, in accordance with general trends found by previous studies. In addition, the elevational variation in live AGB stocks suggests a large spatial variability over coastal Atlantic forests in Brazil, clearly indicating that it is important to consider regional differences in biomass stocks for evaluating the role of this threatened tropical biome in the global carbon cycle. (C) 2010 Elsevier B.V. All rights reserved.

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Stream discharge-concentration relationships are indicators of terrestrial ecosystem function. Throughout the Amazon and Cerrado regions of Brazil rapid changes in land use and land cover may be altering these hydrochemical relationships. The current analysis focuses on factors controlling the discharge-calcium (Ca) concentration relationship since previous research in these regions has demonstrated both positive and negative slopes in linear log(10)discharge-log(10)Ca concentration regressions. The objective of the current study was to evaluate factors controlling stream discharge-Ca concentration relationships including year, season, stream order, vegetation cover, land use, and soil classification. It was hypothesized that land use and soil class are the most critical attributes controlling discharge-Ca concentration relationships. A multilevel, linear regression approach was utilized with data from 28 streams throughout Brazil. These streams come from three distinct regions and varied broadly in watershed size (< 1 to > 10(6) ha) and discharge (10(-5.7)-10(3.2) m(3) s(-1)). Linear regressions of log(10)Ca versus log(10)discharge in 13 streams have a preponderance of negative slopes with only two streams having significant positive slopes. An ANOVA decomposition suggests the effect of discharge on Ca concentration is large but variable. Vegetation cover, which incorporates aspects of land use, explains the largest proportion of the variance in the effect of discharge on Ca followed by season and year. In contrast, stream order, land use, and soil class explain most of the variation in stream Ca concentration. In the current data set, soil class, which is related to lithology, has an important effect on Ca concentration but land use, likely through its effect on runoff concentration and hydrology, has a greater effect on discharge-concentration relationships.

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Environmental quality assessment studies have been conducted with tree species largely distributed in the Atlantic Forest. Leaf and soil samples were collected in the conservation unit Parque Estadual da Serra do Mar (PESM) nearby the industrial complex of Cubatao, Sao Paulo State, Brazil, and analyzed for chemical elements by instrumental neutron activation analysis. Results were compared to background values obtained in the Parque Estadual Carlos Botelho (PECB). The higher As, Fe, Hg and Zn mass fractions in the tree leaves of PESM indicated anthropogenic influence on this conservation unit.

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This study was carried out in a continental Atlantic Forest located in the southern region of Sao Paulo State, southeastern Brazil. The aim of the study was to evaluate the vegetation dynamics in similar to 70 km forest ecosystem transect that occurred during the late Pleistocene and Holocene in this region, using the stable carbon isotopes (delta C-13) analysis on soil organic matter (SOM) and the C-14 dating of buried charcoal fragments and the humin fraction of SOM. The isotope data (delta C-13) of SOM in the deeper horizons, indicating the presence of more open vegetation than the present, with a probable mixture of C-3 and C-4 plants, suggesting the presence of a drier climate in the period of similar to 20 ka to similar to 16-14 ka BP. From similar to 16 to 14 ka BP to the present, a significant predominance Of C3 plants was observed, indicating an expansion of the forest, probably associated with the presence of a more humid climate than the previous period. The results indicated the presence of open vegetation during the late glacial, probably associated with a drier period, also observed in other regions of Brazil. The Atlantic Forest ecosystem seems to have developed at least since the early Holocene in Southeastern Brazil. (c) 2007 Elsevier Ltd and INQUA. All rights reserved.

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The accumulation of chemical elements in biological compartments is one of the strategies of tropical species to adapt to a low-nutrient soil. This study focuses on the Atlantic Forest because of its eco-environmental importance as a natural reservoir of chemical elements. About 20 elements were determined by INAA in leaf, soil, litter and epiphyte compartments. There was no seasonality for chemical element concentrations in leaves, which probably indicated the maintainance of chemical elements in this compartment. Considering the estimated quantities, past deforestation events could have released large amounts of chemical elements to the environment.

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Many different species of Bromeliaceae are endangered and their conservation requires specific knowledge of their growth habits and propagation. In vitro culture of bromeliads is an important method for efficient clonal propagation and ill vitro seed g,germination can be used to maintain genetic variability. The present work aims to evaluate the in vitro growth and nutrient concentration in leaves of the epiphyte bromeliads Vriesea friburguensis Mez, Vriesea hieroglyphica (Carriere) E. Morren, and Vriesea unilateralis Mez, which exhibit slow rates of growth in vivo and in vitro. Initially, we compared the endogenous mineral composition of bromeliad plantlets grown in half-strength Murashige and Skoog (MS) medium and the mineral composition considered adequate in the literature. This approach suggested that calcium (Ca) is a critical nutrient and this was considered for new media formulation. Three new culture media were defined in which the main changes to half-strength MS medium were an increase in Ca, magnesium, sulfur, copper, and chloride and a decrease in iron, maintaining the nitrate: ammonium rate at approximate to 2:1. The main difference among the three new media formulated was Ca concentration, which varied from 1.5 mm in half-strength MS to 3.0, 6.0, and 12 mm in M2, M3, and M4 media, respectively. Consistently, all three species exhibited significantly higher fresh and dry weight on M4, the newly defined medium with the highest level of Ca (12 mm). Leaf nitrogen, potassium, zinc, magnesium and boron concentrations increased as Ca concentration in the medium increased from 1.5 to 12 mm.

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Rare species are one of the principal components of the species richness and diversity encountered in Dense Ombrophilous Tropical Forests. This study sought to analyze the rare canopy species within the Atlantic Coastal Forest in Rio de Janeiro State, Brazil. Six different communities were examined: Dense Ombrophilous alluvial Forest; Dense sub-montane Ombrophilous Forest; Dense Montane Ombrophilous in Serra do Mar and Serra da Mantiqueira. In each area the vegetation was sampled within forty 10 x 25 m plots alternately distributed along a linear transect. All trees with DBH (1.3 m above ground level) a parts per thousand yen5 cm were sampled. The canopy was characterized using the allometric relationship between diameter and height, and included all trees with BDH a parts per thousand yen10 cm and height a parts per thousand yen10 m. A total of 64 families, 206 genera, and 542 species were sampled, of which 297 (54.8%) represented rare species (less than one individual per hectare). The percentage of rare species varied from 34 to 50% in each of the different communities sampled. A majority of these rare trees belonged to the Rosidae, and a smaller proportion to the Dilleniidae. It was concluded that there was no apparent pattern to rarity among families, that rarity was probably derived from a number of processes (such as gap formation), and that a great majority of the rare species sampled were consistently rare. This indicates that the restricted geographic distribution and high degree of endemism of many arboreal taxa justifies the conservation of even small fragments of Atlantic Forest.

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Long-term assessments of species assemblages are valuable tools for detecting species ecological preferences and their dispersal tracks, as well as for assessing the possible effects of alien species on native communities. Here we report a 50-year-long study on population dynamics of the four species of land flatworms (Platyhelminthes, Tricladida, Terricola) that have colonized or become extinct in a 70-year-old Atlantic Forest regrowth remnant through the period 1955-2006. On the one hand, the two initially most abundant species, which are native to the study site, Notogynaphallia ernesti and Geoplana multicolor have declined over decades and at present do not exist in the forest remnant. The extinction of these species is most likely related with their preference for open vegetation areas, which presently do not exist in the forest remnant. On the other hand, the neotropical Geoplaninae 1 and the exotic Endeavouria septemlineata were detected in the forest only very recently. The long-term study allowed us to conclude that Geoplaninae 1 was introduced into the study area, although it is only known from the study site. Endeavouria septemlineata, an active predator of the exotic giant African snail, is originally known from Hawaii. This land flatworm species was observed repeatedly in Brazilian anthropogenic areas, and this is the first report of the species in relatively well preserved native forest, which may be evidence of an ongoing adaptive process. Monitoring of its geographic spread and its ecological role would be a good practice for preventing potential damaging effects, since it also feeds on native mollusk fauna, as we observed in lab conditions.

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The Brazilian Atlantic Forest is one of the richest biodiversity hotspots of the world. Paleoclimatic models have predicted two large stability regions in its northern and central parts, whereas southern regions might have suffered strong instability during Pleistocene glaciations. Molecular phylogeographic and endemism studies show, nevertheless, contradictory results: although some results validate these predictions, other data suggest that paleoclimatic models fail to predict stable rainforest areas in the south. Most studies, however, have surveyed species with relatively high dispersal rates whereas taxa with lower dispersion capabilities should be better predictors of habitat stability. Here, we have used two land planarian species as model organisms to analyse the patterns and levels of nucleotide diversity on a locality within the Southern Atlantic Forest. We find that both species harbour high levels of genetic variability without exhibiting the molecular footprint of recent colonization or population expansions, suggesting a long-term stability scenario. The results reflect, therefore, that paleoclimatic models may fail to detect refugia in the Southern Atlantic Forest, and that model organisms with low dispersal capability can improve the resolution of these models.

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The Brazilian Atlantic Rainforest is internationally recognised as one of the most biodiverse and threatened tropical forests in the world [Myers, N., Mittermeier, R.A., Mittermeier, C.G., da Fonseca, G.A.B., Kent, J., 2000. Biodiversity hotspots for conservation priorities. Nature 403, 853-858]. The Seasonal Semi-Deciduous Forest is among the most fragmented and threatened biomes of the Atlantic Rainforest Domain. The largest remnant of this biome (35,000 ha) is protected by the Morro do Diabo State Park (MDSP), situated in the area known as the Pontal do Paranapanema, in Sao Paulo State, Brazil. Despite its environmental importance, the park is under political, economic and demographic pressure. The main aim of our research was to estimate the population`s willingness to pay (WTP) for the conservation of MDSP and for the Atlantic Rainforest`s remnants in Sao Paulo State as a whole, by means of the contingent valuation method (CVM). The results featured a high incidence of null WTP and of protest votes. Nevertheless, the population is willing to pay US$ 2,113,548.00/year (R$ 7,080,385.00/year) for the conservation of the MDSP (use and existence values), or US$ 60.39 ha/year (R$ 202.30/ha/year). The results indicate that the preservation value is strongly associated to the population`s ability to pay, increasing with income levels. Qualitative research questions showed that the population considers protected areas to be very important. Still, the valuation of MDSP revealed a gap between the government budget allotted to the park and the value assigned to the area by the public. (C) 2007 Elsevier B.V. All rights reserved.

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Objectives: Main Objective: to identify ethical problems in primary care according to nurses` and doctors` perceptions. Secondary Objective: to know ethical issues of patient-professional relationships in primary care. Design: Synthesis to integrate and reinterpret primary results of qualitative studies. Setting: Primary healthcare centers, Sao Paulo, SP, Brazil. Participants and/or context: Incidental sample of 34 nurses and 36 medical doctors working in primary healthcare centers selected by convenience. Methods: Individual, semi-structured interviews to identity situations considered as sources of ethical problems. The sample is socially representative of primary care health centers and professionals. Data collection assured discourse saturation. Hermeneutic-dialectical discourse analysis was used to study the results. Results: Patient-professional relationships and team work were the main sources of ethical problems. The most important problems were patient information, privacy, confidentiality, interpersonal relationship, linkage and patient autonomy. These issues reflect the recent changes in clinical relation ships and show the peculiarities of primary care with its continuous care which lasts a long time. Healthcare involves multiprofessional team work in the midst of the patient claims for autonomy. Good care of patients needs requires a relationship based on communication and cooperation, and includes feelings and values, with communication skills. Conclusions: Ethical problems in primary care are common situations. For quality and humane primary care the relationship should consist of dialogue, trust and cooperation. (C) 2009 Elsevier Espana, S.L. All rights reserved.