982 resultados para eastern deciduous forest
Resumo:
The phlebotomine sandfly fauna of a primary forest reserve at Morretes (eastern Paraná State) was studied, using CDC-like light traps, one night per month, at canopy and ground level, between April 1995 and March 1996. A total of 3,106 insects were collected, identified as belonging to nine species. Lutzomyia ayrozai and Lu.geniculata were predominant, seven other species also being present. Monthly mean temperature, rainfall and the temperature of the collection night significantly influenced the numbers of Lu. ayrozai while the two first factors influenced the numbers of Lu. geniculata, besides the collected quantities of females of the two species. The influence of the factors on Lu. ayrozai numbers was more immediate than in those of Lu. geniculata. Numbers of both species and of the females of Lu. geniculata collected in different seasons, but not at the different heights, varied significantly. Differences between the behaviour of Lu. ayrozai in Morretes and in other regions could be attributed to environmental differences and/or to regional variations in the species, which could constitute species complexes. Hourly variations of collections were different in the species and seasons.
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Due to the occurrence of cases of dermal leishmaniasis in the Municipality of Piçarras, in the East of the Brazilian State of Santa Catarina, collections of Phlebotomine sandflies by the use of CDC-like light traps were developed near the houses of the patients. Three species (Lutzomyia neivai, Lu. fischeri and Lu. ayrozai) were collected. Lu. neivai was predominant near the houses, and Lu. ayrozai was collected in a secondary forest in a nearby municipality (Navegantes). The novelty of this focus, the most southern one in the East of Brazil, underscores the need for more complete studies on the sandfly fauna.
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Natural regeneration and structure and their relationship to environmental variables were studied in three sections of a gallery forest, in Eastern Mato Grosso, Brazil (14º43′S and 52º21′W). The assumption was that natural regeneration is constrained by environmental determinants at all stages of development of the tree community. The objective was to analyse the forest structure and to verify the relationship between species distribution and abundance at different stages of regeneration and environmental variables. In each section, 47 contiguous (10x10m) permanent plots were established to sample trees (gbh≥15cm), following a systematic design. Seedlings (0.01 to 1m height), saplings (1.01 to 2m) and poles (from 2.01m height to gbh<15cm) were sampled in sub-plots of 1x1m, 2x2m and 5x5m, respectively. In each plot, soil properties, gaps projection, bamboos, rocky cover, declivity and depth of ground watertable were determined. The relationships between the environmental variables with trees and seedling communities were assessed by canonical correspondence analysis. In spite of the sections being near to each other, they presented large differences in floristics, structure and site conditions. The forest soil presented a low cation exchange capacity and a high level of Al saturation. The occurrence of bamboos and gaps and the depth of ground watertable limited the occurrence of poles and trees. The high degree of structural heterogeneity for each regeneration category was related primarily to a humidity gradient; but soil fertility (Ca+Mg) was also a determinant of seedling and sapling communities.
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Observational and experimental studies have shown that increased concealment of bird nests reduces nest predation rates. The objective of the present study was to evaluate differences in predation rates between two experimental manipulations of artificial ground nests (i.e., clearing an area around the artificial nest or leaving it as natural as possible), and test whether environmental variables also affected nest predation in an undisturbed area of Amazonian forest in eastern Brazil. A generalized linear model was used to examine the influence of five variables (manipulation type, perpendicular distance from the main trail, total basal area of trees surrounding the nest site, understorey density, and liana quantity) on nest predation rates. Model results, showed that manipulation type was the only variable that significantly affected nest predation rates. Thus, to avoid systematic biases, the influence of nest site manipulation must be taken into consideration when conducting experiments with artificial nests.
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Schefflera morototoni fruits are important food source for neotropical frugivorous birds. The objectives of the present study were to record bird species that consumed fruits of S. morototoni in a forest in the transition Cerrado-Amazon Forest, Mato Grosso, Brazil and evaluate the potential of these bird species as seed dispersers of this plant species. During 31 observation hours, from November 1 to 5, 2011, 23 bird species were recorded consuming S. morototoni fruits. Out of these, 20 bird species were considered potential seed dispersers, as they swallow the fruits whole. The species consuming the greatest number of fruits were Aburria cujubi (24% of total consumed fruits), Pteroglossus castanotis (18%), Tangara palmarum (12%), Patagioenas speciosa (11%), Ramphastos toco (8%), and Dacnis lineata (5%). The species T. palmarum showed the highest visit frequency (VF = 1.51), followed by P. castanotis (VF = 0.80), and D. lineata (VF = 0.77). All bird species employed picking foraging method for removal of fruits and in 11 species (48%) this method was the only one used. Agonistic interactions represented 13% of the total number of visits. Dacnis lineata received the highest number of attacks and P. castanotis and Pitangus sulphuratus were the more aggressive species. The high bird richness and the great number of consumed fruits indicated that the fruits of S. morototoni may be an important food resource for birds in the Cerrado-Amazon Forest transition
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Palms show clear niche segregation patterns along topographic gradients in tropical forests, with some species associated to terra firme and others to seasonally flooded areas. The aim of this study was to quantitatively describe the fine-scale spatial variation within a palm community, tracking the changes in species' abundance along environmental gradients associated with a perennial stream the eastern Amazon. The study of palm communities was based on 60 forest plots in which all adult palms were counted. We found a total of 566 palms in a community containing 11 species. Furthermore, we found a significant separation in the palm community between seasonally-flooded and terra firme forests. We found a gradient with various densities of the three most abundant palm species within the first 100 m away from the flooded area. Other species were located exclusively in the terra firme forest. The abundance of the six most common species were distributed in relation to humidity gradients from floodplains to terra firme, with palm distribution from the most flood-tolerant to the least flood-tolerant palm species as follows: Euterpe oleracea, Attalea phalerata and Socratea exorrhiza (species with floodplain affinity), Astrocaryum gynacanthum, Astrocaryum aculeatum, Attalea maripa (species with terra firme affinity)
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Alpaida guto n. sp. is described based on males and females from State of Pará, Brazil. This species appears to be the most abundant Alpaida O. P.-Cambridge, 1889 species in Caxiuanã National Forest, eastern Amazonia. The males seem to be close to A. antonio Levi, 1988 but can be easily distinguished by the terminal apophysis with rounded distal lobe and long, slender basal prong; females differ from those of A. yotoco Levi, 1988 by the median lobe with a basal constriction and by the bilobed median plate.
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In order to evaluate the efficiency of different mammalian survey methods, we compared traditional sampling techniques (use of camera-traps on roads and artificial trails, track censuses, and direct field visualization) with an alternative sampling design (camera-traps positioned in natural areas such as natural trails and shelters). We conducted the study in a deciduous Atlantic-Forest park in southern Brazil, and additionally compared our results with a previous intensive study carried out in the same area. Our considerably smaller sampling effort (example: 336 trap.day for our camera-traps versus 2,154 trap.day for the earlier study) registered the presence of 85% of the local known species, with camera-traps being 68% efficient. Moreover, shelter camera-traps revealed a different species composition regarding most of other sampling methods. This sampling strategy involving natural forest sites was therefore able to effectively optimize the chances of evaluating species composition in a shorter period, especially with respect to lower-density and cryptic species, as well as to detect species that avoid open, disturbed sites such as roads and man-made forest trails.
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Phylogenetic analysis of all 31 described mitochondrial (cytochrome b) haplotypes of Lutzomyia whitmani demonstrated that new material from the State of Rondônia, in southwest Amazônia, forms a clade within a lineage found only in the rain-forest regions of Brazil. This rain-forest lineage also contains two other clades of haplotypes, one from eastern Amazônia and one from the Atlantic forest zone of northeast Brazil (including the type locality of the species in Ilhéus, State of Bahia). These findings do not favour recognizing two allopatric cryptic species of L. whitmani, one associated with the silvatic transmission of Leishmania shawi in southeast Amazônia and the other with the peridomestic transmission of Le. braziliensis in northeast Brazil. Instead, they suggest that there is (or has been in the recent past) a continuum of inter-breeding populations of L. whitmani in the rain-forest regions of Brazil.
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Two snapshot surveys to establish the diversity and ecological preferences of mosquitoes (Diptera: Culicidae) in the terra firme primary rain forest surrounding the Tiputini Biodiversity Station in the UNESCO Yasuní Biosphere Reserve of eastern Amazonian Ecuador were carried out in November 1998 and May 1999. The mosquito fauna of this region is poorly known; the focus of this study was to obtain high quality link-reared specimens that could be used to unequivocally confirm species level diversity through integrated systematic study of all life stages and DNA sequences. A total of 2,284 specimens were preserved; 1,671 specimens were link-reared with associated immature exuviae, all but 108 of which are slide mounted. This study identified 68 unique taxa belonging to 17 genera and 27 subgenera. Of these, 12 are new to science and 37 comprise new country records. DNA barcodes [658-bp of the mtDNA cytochrome c oxidase ( COI ) I gene] are presented for 58 individuals representing 20 species and nine genera. DNA barcoding proved useful in uncovering and confirming new species and we advocate an integrated systematics approach to biodiversity studies in future. Associated bionomics of all species collected are discussed. An updated systematic checklist of the mosquitoes of Ecuador (n = 179) is presented for the first time in 60 years.
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A new species of Plebeia, the second largest genus of stingless bees in the Neotropical region, is described from eastern Brazil. Plebeia grapiuna sp. nov., known only from the lowland forests of southern Bahia, is most similar to P. lucii Moure, a species recently described from Minas Gerais. The lack of yellow marks and the smoother integument of the frons and mesoscutum in P. grapiuna sp. nov. distinguish them. Main features of the nesting habits of the new species are described and illustrated.
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Payments for Environmental Services (PES) are praised as innovative policy instruments and they influence the governance of forest restoration efforts in two major ways. The first is the establishment of multi-stakeholder agencies as intermediary bodies between funders and planters to manage the funds and to distribute incentives to planters. The second implication is that specific contracts assign objectives to land users in the form of conditions for payments that are believed to increase the chances for sustained impacts on the ground. These implications are important in the assessment of the potential of PES to operate as new and effective funding schemes for forest restoration. They are analyzed by looking at two prominent payments for watershed service programs in Indonesia-Cidanau (Banten province in Java) and West Lombok (Eastern Indonesia)-with combined economic and political science approaches. We derive lessons for the governance of funding efforts (e.g., multi-stakeholder agencies are not a guarantee of success; mixed results are obtained from a reliance on mandatory funding with ad hoc regulations, as opposed to voluntary contributions by the service beneficiary) and for the governance of financial expenditure (e.g., absolute need for evaluation procedures for the internal governance of farmer groups). Furthermore, we observe that these governance features provide no guarantee that restoration plots with the highest relevance for ecosystem services are targeted by the PES
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Soil plays an important role in the C cycle, and substitution of tropical forest by cultivated land affects C dynamic and stock. This study was developed in an area of expansion of human settlement in the Eastern Amazon, in Itupiranga, State of Pará, to evaluate the effects of native forest conversion to Brachiaria brizantha pasture on C contents of a dystrophic Oxisol. Soil samples were collected in areas of native forest (NF), of 8 to 10 year old secondary forest (SF), 1 to 2 year old SF (P1-2), 5 to 7 year old SF (P5-7), and of 10 to 12 year old SF (P10-12), and from under pastures, in the layers 0-2, 2-5 and 5-10 cm, to evaluate C levels and stocks and carry out separation of OM based on particle size. After deforestation, soil density increased to a depth of 5 cm, with greater increase in older pastures. Variation in C levels was greatest in the top soil layer; C contents increased with increasing pasture age. In the layers 2-5 and 5-10 cm, C content proved to be stable for the types of plant cover evaluated. Highest C concentrations were found in the silt fraction; however, C contents were highest in the clay fraction, independent of the plant cover. An increase in C associated with the sand fraction in the form of little decomposed organic residues was observed in pastures, confirming greater sensitivity of this fraction to change in soil use.
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ABSTRACT The use of fire to prepare agricultural areas is a technique still used by small farmers in eastern Amazon. This type of management changes the dynamics of soil nutrients, especially phosphorus, which constitutes the most limiting nutrient for crop production in tropical soils. This study was carried out to evaluate changes in phosphorus forms in an Argissolo Amarelo Distrófico (Ultisol) submitted to burning and trituration of secondary forest in eastern Amazon. The evaluated systems were: slash-and-burn of vegetation; slash-and-mulch of vegetation; and secondary vegetation. The labile, moderately labile, moderately recalcitrant, available and total phosphorus fractions were assessed at the soil depths of 0.00-0.05, 0.05-0.10 and 0.10-0.20 m. The results showed a predominance of soluble P in acid (moderately labile P) over other forms in all management systems. The management systems influence the content and distribution of the forms of P, where the slash-and-mulch system presented the prevalence of the labile fraction, and the slash-and-burn system contained less labile forms. The slash-and-mulch system favored the accumulation of labile P and total organic P.
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Landslides are an increasing problem in Nepal's Middle Hills due to both natural and human phenomena: mainly increasingly intense monsoon rains and a boom in rural road construction. This problem has largely been neglected due to underreporting of losses and the dispersed nature of landslides. Understanding how populations cope with landslides is a first step toward developing more effective landslide risk management programs. The present research focuses on two villages in Central-Eastern Nepal, both affected by active landslides but with different coping strategies. Research methods are interdisciplinary, based on a geological assessment of landslide risk and a socio-economic study of the villages using household questionnaires, focus group discussions and transect walks. Community risk maps are compared with geological landslide risk maps to better understand and communicate community risk perceptions, priorities and coping strategies. A modified typology of coping strategies is presented, based on previous work by Burton, Kates, and White (1993) that is useful for decision-makers for designing more effective programs for landslide mitigation. Main findings underscore that coping strategies, mainly seeking external assistance and outmigration, are closely linked to access to resources, ethnicity/social status and levels of community organization. Conclusions include the importance of investing in organizational skills, while building on local knowledge about landslide mitigation for reducing landslide risk. There is great potential to increase coping strategies by incorporating skills training on landslide mitigation in existing agricultural outreach and community forest user group training.