231 resultados para RICAN RAIN-FOREST


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Studies on the regeneration and seedling mortality of rare tree species are important, but scarce. The aim of this study was to investigate the annual variation in recruitment, growth and mortality of juveniles of Enterolobium glaziovii Benth., a rare tree species from the Brazilian Atlantic Rain Forest. All seedlings and juveniles around four reproductive trees were labeled and their fate was followed from 1996 to 1999. There were no annual differences in juveniles' recruitment below and beyond the parental crown, but juveniles' survival and growth were lower below than beyond of the parental tree crowns. Small individuals (< 15 cm tall) showed the greatest mortality and the lowest growth, followed by medium (from 15 to 50 cm tall) and large ones (> 50 cm tall). Large juveniles were more widely dispersed from the conspecific parental tree than were medium and small ones. This suggests that distance dependent mortality of juveniles mediated by the parental tree is an important cause of spacing shifts associated with the growth of small individuals of E. glaziovii into large ones. Widely dispersed juveniles may escape the high mortality associated with pathogens, herbivores or seed predators concentrated around adult conspecifics. The negative influence of the parental tree on its juveniles may explain the sparse distribution of its adults in the forest.

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INTRODUCTION: Manaus, the capital city of the state of Amazon with nearly 2 million inhabitants, is located in the middle of the Amazon rain forest and has suffered dengue outbreaks since 1998. METHODS: In this study, blood samples were investigated using reverse transcriptase-polymerase chain reaction (RT-PCR), aimed at identifying dengue virus serotypes. RESULTS: Acute phase sera from 432 patients were tested for the presence of dengue virus. Out of the 432 patients, 137 (31.3%) were found to be positive. All the four dengue virus serotypes were observed. CONCLUSIONS: The simultaneous circulation of the four dengue serotypes is described for the first time in Manaus and in Brazil.

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INTRODUCTION: This work aimed to study the community structure of sandflies, with regard to the richness, constancy, abundance, and monthly frequency of the species with a focus on the transmission of leishmaniasis. METHODS: The study was conducted in the rural villages of Bom Jardim and Santa Maria, situated on the edge of a tropical rain forest in the municipality of São Jose de Ribamar, Maranhão, Brazil. The phlebotomines were captured in the intradomiciles and peridomiciles of each village, with Centers for Disease Control (CDC) light traps set in 10 homes in each village, for 1 year, once a month, from 18h to 6h. RESULTS: We collected 1,378 individuals of 16 sandfly species. The capture success rate was higher in Bom Jardim (0.61 specimens/hour/trap) than that of Santa Maria (0.35/specimens/hour/trap). The sandflies were more abundant in the peridomiciles (86.1%) and in the rainy season (77%). Five species were considered constants (occurring in more than 50% of samples), 5 accessory (25%-50%), and 6 accidental (<25%). The most abundant species were Lutzomyia longipalpis (59.7%) and L whitmani (28%). The permutation analysis showed differences between the species composition of the villages and no separation between the intradomicile and peridomicile of each village. The species that most contributed to the dissimilarity between the light traps of the 2 villages were L. longipalpis, L. whitmani, and L. evandroi, contributing to 80.8% of the variation among groups. CONCLUSIONS: The high level of richness and abundance of species and the presence of competent vectors throughout the year and around houses justify the occurrence of leishmaniasis cases reported in the area.

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A Socioecological Field Study.This monograph reports on a 26 month socioecological study of black spider monkeys (Ateles paniscus paniscus)in the Raleigh-vallen — Voltzberg Nature Reserve, Surinam. It recognizes the fundamental importance of food to the behavior and the regulation of population density fox this primate. It clarifies the complex temporal and spatial effects of tropical rain forest food sources on the behavior of a group of spider monkeys, concentrating on food category, food plant identity and phenology, and quantity, density and dispersion of the most important food sources. In addition, the present study describes habitat choice, optimal feeding strategy and sexual behavior of the spider monkey, and discusses implications of diet for social behavior. This study is also fundamental to conservation. Specialized in eating mature fruits, the spider monkey is a very important dispersal agent for many trees and lianes, particularly canopy species. However, the spider monkey is probably the most vulnerable monkey species in Surinam and it is disappearing rapidly throughout the remainder of its range. Unfortunately, it is large and noisy and can be easily tracked and hunted. It is largely restricted to undisturbed high forest, and consequently habitat destruction has more effect on it than on most other species. Together with its slow reproductive rate (a female gives birth only once every four or five years), this means that the species is poorly adapted to recover from exploitation. In order to implement proper measures for conservation, data on forest type preferences, diet and social behavior of the species, or on closely related species, in undisturbed areas, such as the one described in this monograph, are essential tools for assessing the potential of proposed protected areas.

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The leaf-feeding species Syntermes molestus and S. spinosus are two dominant termite species in Reserva Ducke in Central Amazonia; two other species (S. aculeosus, S. longiceps) exist in the area. All species except S. aculeosus were also found in urban areas. The workers of S. molestus and S. spinosus have average body dry weights of 4.5±0.2 and 13.1±1.4 mg, and the weight of their soldiers is 8.2±0.2 and 51.0±1.7 mg, respectively. Therefore, S. spinosus is among the largest termites of the world. In both species, fresh weight is about 4.7 higher than dry weight (a wider relation than in other termite species). The biomass of the populations of both species amounted to about 1 g m-2 (dry weight; indirect estimate), which rises previous assessments of the total termite biomass by about 36-45%, to a value of 3.0-3.5 g m-2.

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The intensity of construction of foraging access holes by two leaf-litter feeding, soil- inhabiting termite species, Syntermes molestus and Syntermes spinosus, in a Central Amazonian rain forest, was observed on consecutive nights for two weeks. Between 11 and 48 nest entrances per m2 were counted. Interaction between the two species was intense; some entrance holes were overtaken by the larger species during the observations; however, both species coexist in the area. A calculated minimum of 35 entrances/m2 is built every year by both species, emphasizing the importance of soil-burrowing termites for soil structure, aeration and water regime.

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Fine litter dynamics within the canopy differ from litter dynamics on the forest floor for reasons such as differences in microclimate, substrate, disturbance level, stratum influence and decomposition rates. This study is the first attempt to quantify the fine litter accumulated in the canopy of Central Amazonian forests. We compared the canopy litter accumulation to fine litter-layer on forest floor and to other forests and also investigated which were the mostly accumulated litter omponents. We found that Central Amazonian Rainforest intercepts greater fine litter in the canopy (294 g.m-2) compared to other forest formations with higher winds speed as in a Costa Rican Cloud Forest (170 g.m-2). The mean canopy fine litter accumulated at the end of the dry season was less than a half of that on soil surface (833 g.m-2) and the fine wood component dominates the canopy samplings (174 g.m-2) while leafy component predominate on soil surface litter (353 g.m-2).

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Alho do mato (Cipura paludosa, Iridaceae) is a medicinal plant found in the Amazon rain forest, North of Brazil. It has been used to treat algic, inflammatory and infectious processes. The aim of this study was to evaluate the anti-inflammatory and antinociceptive action of the crude Cipura paludosa ethanolic extract at concentrations ranging between 2.0 and 4.0% in Oil and Water cream formulations for topical use. The physical-chemical stability of the formulations was monitored over a six-month period with the use of accelerated stability tests. In order to evaluate the anti-inflammatory and antinociceptive activities, we used a paw edema test induced by carrageenan and a formalin test, respectively. The paw edema test showed that there was a statistical difference in the control group in relation to the treatments. The formalin test did not confirm antinociceptive action of the treatments with the extract in the early phase of the test. However, statistical difference was confirmed for the treatments in relation to the control in the late phase. The antinociceptive and anti-inflammatory activities of Cipura paludosa preparations, as demonstrated in the results, at least partially support the ethno-medical uses of this plant.

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The breeding activity of Physalaemus signifer (Girard, 1853) was monitored from July 1999 to July 2000 in a temporary pond in Palmital, Municipality of Saquarema, State of Rio de Janeiro, Atlantic Rain Forest, Brazil. Males were sexually actives only in four nights, arriving at the pond on the early rainy season. Males in amplexus were larger and spent more nights in the reproductive aggregation than solitary ones. The number of nights was correlated with the mass of the males. Males adopted satellite behavior as alternative tactic for mate acquisition. Changes between calling and satellite tactics were observed in different nights. Calling males were not larger and heavier than satellite ones. Satellite behavior seemed to be related with the order of arrival on the pond. Size and mass of males did not influence the results of fights. Resident males won the majority of agonistics combats. Three types of vocalizations are described: advertisement, territorial, and encounter calls.

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Six new species of Trichomyia from Atlantic rain forest of Bahia, northeastern Brazil, are described: T. itabunensis, T. onorei, T. queirozi, T. silvatica, T. sulbaianensis and T. teimosensis. The first two have palpi with four segments, similar to the other Neotropical species. The other four species have palpi with three segments, similar to other species with wide world distribution.

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Maruina menina sp. nov., from Atlantic rain forest of Bahia, northeastern Brazil, is described and illustrated.

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The tadpole of Hypsiboas atlanticus (Caramaschi & Velosa, 1996) is described from the municipality of Maceió, State of Alagoas, Brazil. At stage 36 the larvae have an overall elliptical body in lateral and dorsal views, oral disc anteroventral, spiracular tube sinistral, and labial tooth row formula 2(1,2)/3(1). The oral disc is surrounded, almost completely (anterior medial gap present) by a single row of marginal papillae. Described tadpoles of the H. punctatus species group can be differentiated by a combined disc oral features. Additional descriptions of H. punctatus (Schneider, 1799) tadpoles from populations throughout South America may be helpful in determining the status of these populations.

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The definition of areas of endemism is central to studies of historical biogeography, and their interrelationships are fundamental questions. Consistent hypotheses for the evolution of Pentatomidae in the Neotropical region depend on the accuracy of the units employed in the analyses, which in the case of studies of historical biogeography, may be areas of endemism. In this study, the distribution patterns of 222 species, belonging to 14 Pentatomidae (Hemiptera) genera, predominantly neotropical, were studied with the Analysis of Endemicity (NDM) to identify possible areas of endemism and to correlate them to previously delimited areas. The search by areas of endemism was carried out using grid-cell units of 2.5° and 5° latitude-longitude. The analysis based on groupings of grid-cells of 2.5° of latitude-longitude allowed the identification of 51 areas of endemism, the consensus of these areas resulted in four clusters of grid-cells. The second analysis, with grid-cells units of 5° latitude-longitude, resulted in 109 areas of endemism. The flexible consensus employed resulted in 17 areas of endemism. The analyses were sensitive to the identification of areas of endemism in different scales in the Atlantic Forest. The Amazonian region was identified as a single area in the area of consensus, and its southeastern portion shares elements with the Chacoan and Paraná subregions. The distribution data of the taxa studied, with different units of analysis, did not allow the identification of individual areas of endemism for the Cerrado and Caatinga. The areas of endemism identified here should be seen as primary biogeographic hypotheses.

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The environment most diverse in harvestmen species is the Atlantic Forest of São Paulo. However, there remains a lack of studies regarding their communities in certain regions. Among these regions is one south of the Paranapiacaba mountain range in the state of São Paulo, the Parque da Onça Parda (POP). Through nocturnal collections and pitfall traps, the region's harvestmen community has been studied. The observed richness of this site included 27 species, with dominance of three species: Holcobunus nigripalpis Roewer, 1910, Neosadocus maximus (Giltay, 1928) and Munequita sp., accounting for 68.4% of harvestmen abundance. This makes the diversity of POP more similar to the semideciduous Atlantic Forest communities of the interior than to those of the Coastal Atlantic Forest that contains the park. Its geographic location places it within the Southern São Paulo State (SSP) area of endemism, along with the Parque Turístico do Alto Ribeira (PETAR), with which it shares up to 12% similarity regarding harvestmen fauna. Richness and abundance of harvestmen were positively related to temperature and humidity. The period of animal activity (as measured by abundance and richness) varied throughout the night, being highest in the early hours during both studied seasons (summer and winter).

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The present paper is a simple introduction to the ecological requirements of Cephaelis ipecacuanha and only a few preliminary conclusions are reached. Cephaelis ipecacuanha has the habit of a forest plant, which is closely connected with the meteorological and floristic factors. This makes it very necessary to study its ecolo-gical relationships carefully, so as to understand its productivity in accordance with its mi¬croclimatic and microedaphic reactions. Conclusions: 1 — Within the ecological range of Cephaelis ipecacuanha, some zones show more fa¬vourable phytosociological conditions than other zones. Consequently, the vegetative and biological types must be investigated in different associations. a — The most favourable vegetative and biological types encountered, in regard to the phytosociological characteristcs of Cephaelis ipecacuanha, were found respectively in the rain forest on the slopes of the Serra dos Parecis and in the serclimax of the river Galera and its tributaries. b — The phytosociological optimum of Cephaelis ipecacuanha was seen in the Vochysietum (Vochysia sp.) which corresponds to number 11 of the original text. It can be defined as follows: shading by vegetation approximately 90%, as the herbaceous sinusium covers 90% of the area worked in, though the arboreal and arbustive coverture is only 65% and 60% respectviely. The inclination is pratically nil (less than 5°) but the drainage is good because the soil is deep and silicous-humous, thus facilitating infiltration by the rain water which inundates the ground temporarily during the periods of floods. The pH oscillates between 5 and 6, denoting a slightly acid soil.