182 resultados para Atlantic Forest. Ecological corridors. Geographic inference. Scenarios


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ABSTRACTMales of Euglossa mandibularis were consistently captured in scent traps baited with β-ionone in areas of Mixed Ombrophylous Forests or transition between this latter physiognomy and Montane Semideciduous Forest at Parque Nacional do Iguaçu, Paraná state, Brazil. Geographic records for the species and sampling effort (including or not β-ionone among the offered compounds) along Atlantic Forest biome are presented and discussed. We also discuss seasonal and geographic variation in collection of scents by orchid bees.

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The Restinga vegetation consists of a mosaic of plant communities, which are defined by the characteristics of the substrates, resulting from the type and age of the depositional processes. This mosaic complex of vegetation types comprises restinga forest in advanced (high restinga) and medium regeneration stages (low restinga), each with particular differentiating vegetation characteristics. The climate along the coast is tropical (Köppen). Of all ecosystems of the Atlantic Forest, Restinga is the most fragile and susceptible to anthropic disturbances. Plants respond to soil characteristics with physiological and morphological modifications, resulting in changes in the architecture (spatial configuration) of the root system. The purpose of this study was to characterize the soil fertility of high and low restinga forests, by chemical and physical parameters, and its relation to the root system distribution in the soil profile. Four locations were studied: (1) Ilha Anchieta State Park, Ubatuba; (2) two Ecological Stations of Jureia-Itatins and of Chauás, in the municipality of Iguape; (3) Vila de Pedrinhas in the municipality of Ilha Comprida; and (4) Ilha do Cardoso State Park, Cananeia. The soil fertility (chemical and physical properties) was analyzed in the layers 0-5, 0-10, 0-20, 20-40 and 40-60 cm. In addition, the distribution of the root system in the soil profile was evaluated, using digital images and the Spring program. It was concluded that the root system of all vegetation types studied is restricted to the surface layers, 0-10 and 10-20 cm, but occupies mainly the 0-10 cm layer (70 %); that soil fertility is low in all environments studied, with base saturation values below 16 %, since most exchange sites are occupied by aluminum; and that restinga vegetation is edaphic.

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The Brazilian East coast was intensely affected by deforestation, which drastically cut back the original biome. The possible impacts of this process on water resources are still unknown. The purpose of this study was an evaluation of the impacts of deforestation on the main water balance components of the Galo creek watershed, in the State of Espírito Santo, on the East coast of Brazil. Considering the real conditions of the watershed, the SWAT model was calibrated with data from 1997 to 2000 and validated for the period between 2001 and 2003. The calibration and validation processes were evaluated by the Nash-Sutcliffe efficiency coefficient and by the statistical parameters (determination coefficient, slope coefficient and F test) of the regression model adjusted for estimated and measured flow data. After calibration and validation of the model, new simulations were carried out for three different land use scenarios: a scenario in compliance with the law (C1), assuming the preservation of PPAs (permanent preservation areas); an optimistic scenario (C2), which considers the watershed to be almost entirely covered by native vegetation; and a pessimistic scenario (C3), in which the watershed would be almost entirely covered by pasture. The scenarios C1, C2 and C3 represent a soil cover of native forest of 76, 97 and 0 %, respectively. The results were compared with the simulation, considering the real scenario (C0) with 54 % forest cover. The Nash-Sutcliffe coefficients were 0.65 and 0.70 for calibration and validation, respectively, indicating satisfactory results in the flow simulation. A mean reduction of 10 % of the native forest cover would cause a mean annual increase of approximately 11.5 mm in total runoff at the watershed outlet. Reforestation would ensure minimum flows in the dry period and regulate the maximum flow of the main watercourse of the watershed.

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ABSTRACT This study investigates the flowering and pollinators of the floral morphs of three co-occurring distylous species, Psychotria conjugens Müll, P. hastisepala Müll. Arg. and P. sessilis Vell., in two consecutive flowering seasons in an Atlantic Forest fragment in southeastern Brazil. The species have diurnal, cream-colored, tubular, nectariferous flowers and their flowering occurs in the rainy season, from September to April, with little or no overlapping between species, characterizing a staggered flowering. The flowering of the long-and short-styled floral morphs of each species was synchronous, but the number of open flowers per day per morph tended to vary in each flowering season. These numbers were higher in P. sessilis and P. conjugens and, probably, resulted in higher total numbers of visits on its flowers (up to 1084 visits in P. sessilis and 756 in P. conjugens), compared to that observed in P. hastisepala (up to 71). There was a higher frequency of visits to long-styled flowers of all species. The bee Ariphanarthra palpalis was a common pollinator to all species. This bee is native to Brazil, solitary, considered relatively rare and its host plants were unknown. Other native bees (Melipona spp.) also visited the flowers of the Psychotria species. The availability of flowers with similar floral features over eight months, the staggered flowering and common pollinators appear to be part of a strategy to attract floral visitors, minimizing the competition for pollinators and then favoring the legitimate pollination of these plants.

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ABSTRACT The present study aimed to analyze the production and decomposition of litterfall in a fragment of secondary Atlantic forest in the region of Ibiúna, SP, from April 2012 to March 2013. The litterfall production was estimated by 30 collectors distributed randomly in an area of 1000 m2, where the deposited material was collected every 15 days. The decomposition of litterfall was estimated through the mass loss in the period of study. After collecting, the material was dried in an oven at 65 °C for seven days to achieve a constant weight. The decomposition constant k was obteined according to Shanks and Oslon (1961) and the time for 50% and 95% of decomposition was estimated. It was found a higher litterfall production in October (454.3 kg ha-1) and lower production in July (164.9 kg ha-1), with a total amount produced of 3.5 Mg ha-1 year-1. A delay of one month in the precipitation and relative humidity showed great influence in the litter production during the study. The decomposition rate (k) was 3.1 and the time to decompose 50% of the material was estimated in 2 and ½ months and for 95% of the litterfall the time was estimated in 11 and ½ months. The production and decomposition values of this work are within the range found in other sites of secondary tropical forests.

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The effects of disturbances on plant community structure in tropical forests have been widely investigated. However, a majority of these studies examined only woody species, principally trees, whereas the effects of disturbances on the whole assemblage of vascular plants remain largely unexplored. At the present study, all vascular plants < 5m tall were surveyed in four habitats: natural treefall gaps, burned forest, and their adjacent understorey. The burned area differed from the other habitats in terms of species composition. However, species richness and plant density did not differ between burned area and the adjacent understorey, which is in accordance to the succession model that predict a rapid recovery of species richness, but with a different species composition in areas under moderate disturbance. The treefall gaps and the two areas of understorey did not differ among themselves in terms of the number of individuals, number of species, nor in species composition. The absence of differences between the vegetation in treefall gaps and in understorey areas seems to be in agreement with the current idea that the species present in treefall gaps are directly related to the vegetation composition before gap formation. Only minimal differences were observed between the analyses that considered only tree species and those that considered all growth habits. This suggests that the same processes acting on tree species (the best studied group of plants in tropical forests) are also acting on the whole assemblage of vascular plants in these communities.

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Cedrela odorata L. (Meliaceae) occurs in the Atlantic forest, Amazon rain forest, riparian forest of the country, and wetlands, which demand species adapted to their water conditions. Studies in ecological wood anatomy demonstrated that weather factors' variations have direct influence on the wood anatomical structure and that the fragmentation of the natural habitats is a direct cause of the edge effect which alters the abiotic aspects of the location, interfering consequently in its vegetation. A comparative analysis of 20 anatomical quantitative features of the wood structure was performed in populations of Cedrela odorata growing inside and on the edge of the swamp forest and granulometric analysis was made on the soil. The quantitative data were submitted to the Mann-Whitney's nonparametric test, presenting a statistically significant value decrease in the eleven wood features mean for the specimens growing in the edge of swamp forest.

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Soil characteristics related to the genesis, land use and management are important factors in water dynamics in watersheds. This study evaluated physical, morphological and pedogenetic attributes related to water yield potential in small watersheds in Guarapari, ES, Brazil. The following representative profiles were selected, morphologically described and sampled in area of Atlantic Forest domain: Lithic Udifolists, Oxyaquic Udifluventes, Typic Paleudults, Typic Hapludults, Typic Hapludox, Oxic Dystrudepts and Typic Endoaquents. Samples were collected in the soil profiles for physical analysis. Measurements of field-saturated hydraulic conductivity and soil penetration resistance were perfomed in some profiles, which were under different uses. The Endoaquents of Limão Creek can be considered efficient as temporary water reservoirs. However, the use of artificial drainage tends to reduce this effect. Differential erosion was detected by the sand texture on the surface of the Typic Paleudults due to the low degree of clay flocculation, slope, high resistance to the penetration and low hydraulic conductivity of the Bt horizon, making it necessary to adopt soil management practices to increase the water infiltration. Under pasture, mainly in the cattle trails where the trampling is more intense, there was high resistance to penetration in the superficial layers of the Typic Hapludults. The Typic Hapludox have the greatest potential for water yield in the small watersheds because of its greater extent in the headwaters and their morphological and physical characteristics, which can result in increased aquifer recharge.

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The hantavirus pulmonary syndrome was first recognized in cases that occurred in the U.S. in 1993, which served as an alert not only for American physicians but also for physicians in other countries for the identification of the disease. In the city of São Paulo, Brazil, 3 cases of the syndrome were recorded in 1993. The patients were young brothers residing in the Mata Atlântica (Atlantic Forest) region submitted to recent deforestation. Two of the patients died of acute respiratory insufficiency and the third recovered without sequelae. In the surviving patient the diagnosis was established by a laboratory criterion based on the detection of specific IgM and IgG class antibodies by indirect immunofluorescence. In the two patients who died, the diagnosis was confirmed by laboratory tests using immunoperoxidase technique for hantavirus in tissue, in histological lung and heart sections in one case, and by clinical and epidemiological data in the other

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Malaria in Brazil is endemic in the Amazon region, but autochthonous cases with low parasitaemia occur in the Atlantic Forest area of the country. According to Brazilian legislation no test is mandatory for blood donors from non-endemic areas. However if they have traveled to malaria transmission regions they are deferred for six months before they can donate. This report describes a transfusion-transmitted malaria case in Sao Paulo, Brazil, where one recipient received infected blood and developed the disease. He lived in Sao Paulo and had no previous transfusion or trips to endemic areas, including those of low endemicity, such as Atlantic Forest. Thick blood smears confirmed Plasmodiummalariae. All donors lived in Sao Paulo and one of them (Donor 045-0) showed positive hemoscopy and PCR. This asymptomatic donor had traveled to Juquia, in the Atlantic Forest area of S ao Paulo State, where sporadic cases of autochthonous malaria are described. DNA assay revealed P. malariae in the donor's (Donor 045-0) blood. Serum archives of the recipient and of all blood donors were analyzed by ELISA using both P. vivax and P. falciparum antigens, and IFAT with P. malariae. Donor 045-0's serum was P. malariae IFAT positive and the P. vivax ELISA was reactive. In addition, two out of 44 donors' archive sera were also P. vivax ELISA reactive. All sera were P. falciparum ELISA negative. This case suggests the need of reviewing donor selection criteria and deferral strategies to prevent possible cases of transfusion-transmitted malaria.

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Three isolates of Leishmania were recovered from five of 27 specimens of the rodent Proechimys iheringi denigratus Moojen captured near Três Braços in the Atlantic Forest region of Bahia, Brazil. Two of these isolates were recovered from hamsters inoculated with a pooled triturate of liver, spleen and skin tissue from apparently healthy P. i. denigratus. The third isolate was recovered from a triturate of only skin tissue from another. Metastasis was observed in the inoculated hamsters, the parasites grew abundantly in artificial media and a typical suprapylarial pattern of infection in Lutzomyia longipalpis was produced indicating that the parasites belong to the Leishmania mexicana complex. All isolates reacted with Leishmania mexicana mexicana and Leishmania mexicana amazonensis monoclonal antibodies. The isoenzyme analysis differentiated these isolates from standard isolates of L. m. mexicana, L. m. amazonensis, L. m. aristedesi, L. m. pifanoi, L. m. garnhami and L. m. ssp.(Goiás-W. Barbosa). These isolates seem to be a subspecies of L. mexicana very closely related to L. m. amazonensis from which they differ by decreased electrophoretic mobility of GPI, PEP and ALAT. This is the first record of the isolation of a parasite of thegenus Leishmania in a rodent captured in the State of Bahia.

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INTRODUCTION: The presence of American cutaneous leishmaniasis (ACL) in the communities of the Campus FIOCRUZ Mata Atlântica (CFMA) in the City of Rio de Janeiro initiated the investigation of the Phlebotominae fauna in the Atlantic Forest to determine the occurrence of putative ACL vectors associated with the enzootic cycle. METHODS: For 24 consecutive months, sand flies were captured inside the forest and in the border area near the communities. RESULTS: The following sand fly species were identified: Brumptomyia brumpti, Brumptomyia cunhai, Brumptomyia nitzulescui, Lutzomyia edwardsi, Lutzomyia pelloni, and Lutzomyia quinquefer. Other identified sand fly vectors, such as Lutzomyia intermedia (the predominant species), Lutzomyia migonei, Lutzomyia whitmani, Lutzomyia fischeri, and Lutzomyia hirsuta hirsuta, are associated with ACL transmission, and the vector for American visceral leishmaniases (AVL), Lutzomyia longipalpis, was also found. CONCLUSIONS: All sand fly vectors were found in both studied environments except for Lutzomyia whitmani, which was only identified in the forest. This study represents the first identification of Lutzomyia longipalpis in the CFMA, and the epidemiological implications are discussed.

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The squirrel monkey Saimiri sciureus, an endemic primate of the Amazonian Basin, has been introduced in many localities of the Atlantic Forest biome. Introduced exotic species gain a competitive advantage in their new environment because of a lack of natural predators, competitors or diseases. This advantage can result in a reduction in the resources for the endemic species. The aims of this work were to evaluate the level of adaptation, and monitor the forms of interaction and the impact caused by S. sciureus on the behavior of the native species Callithrix jacchus in the Saltinho Biological Reserve, Tamandaré, Pernambuco, Brazil. The behavior was assessed by use of scan sampling method, every 5 min. A total of 382 h (191 h or 2,292 scans per group) of time sampling was performed. Sixteen interactions were recorded. The interaction index was low and represented 2.4% of the total observation time. Interactions were significantly higher during the dry season (58.5%) relative to the rainy season (41.5%). Callithrix jacchus was intolerant to the presence of S. sciureus and the last one was more tolerant during the interactions. In the presence of S. sciureus, C. jacchus eating, foraging, resting, socializing, and self-grooming behaviors were reduced while alertness was increased. Territorial behavior showed no significant difference. In the presence of S. sciureus, on average, the group of marmosets assembled at a higher layer of the forest stratum. The results might indicate a negative effect of S. sciureus on the native species, C. jacchus.

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During two consecutive years, from January 1985 to December 1986, a comparative study of mosquitoes preferences for breeding habitat was carried out in the Atlantic Forest of the Serra do Mar, Paraná State, Brazil. To achieve it, 1875 bamboo internodes aligned vertically in live green, bamboo plants Merostachys speciosa Munro and Merostachys sp. were used, in which metabolic water was exuded from the plant itself, and presenting different size/pattern holes at their lateral walls, bored by the local sylvan fauna. Another group of 1200 individual internode traps was used as comparative element, carved out with a transversal cut by a saw, filled with local stream water and held in branches at different heights in the vegetal strata nearby. At both microhabitat types, a total of 17 culicid species was registered. Culex (Microculex) neglectus Lutz, 1904, Cx. (Carrollia) soperi Antunes & Lane, 1937, Sabethes (Sabethes) batesi Lane & Cerqueira, 1942 and Sa. (Sabethinus) melanonymphe (Dyar, 1924)colonized exclusively live plant internodes, while Culex (Microculex) elongatus Rozeboom & Lane, 1950, Cx. (Carrollia) iridescens (Lutz, 1905), Cx. (Carrollia) kompi Valencia,1973and Trichoprosopon (Trichoprosopon) soaresi Dyar & Knab, 1907 bred only in internode traps. The remaining nine species colonized both habitats indistinctly. Quantitatively, was detected the abundance of 60.1% at live green internodes, against 39.9% for internode traps. Concerning the different patterns of bored live internode holes, 40.3% of the total computed specimens were collected in square or rectangular holes, 31.9% in two hole internodes, one minute circular, the other wider, and the remaining 28.8% of specimens distributed in other pattern type internodes. The mosquitoes breeding at these microhabitats fall in the culicid entomofauna specialized at locating and detecting peculiar and propitious mesogen conditions for breeding purposes.

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From October 1995 to January 1996 Aedes (Ochlerotatus) scapularis (Rondani, 1948) was studied in a small area of the Atlantic Forest, Serra do Marumbi, Morretes, Paraná, Brazil. Adults were captured with Shannon light traps for 48 nights, representing 12 nights for seven time intervals. Traps were operated from dusk to dawn. The influences on flight activity of the lunar phase, ambient temperature, relative humidity, and rainfall were analyzed. Ae. scapularis had a flight behaviour different in each of the four lunar phases. In relation to flight period, the species showed higher activity during the first three lunar intervals. Among the climatic variables, temperature and relative humidity positively influenced flight activity during the night.