Navegando por Assunto "Portel - PA"

Agora exibindo 1 - 17 de 17

Acesso aberto (Open Access)
Aspectos reprodutivos e alimentares da piranha Serrasalmus gouldingi fink & machado-allison, 1992 (Characiformes: Serrasalmidae) em rios afogados da Amazônia Oriental
(Universidade Federal do Pará, 2012) PRUDENTE, Bruno da Silveira; MONTAG, Luciano Fogaça de Assis; http://lattes.cnpq.br/4936237097107099
The present work aimed to evaluate the reproductive biology, condition factor and feeding ecology of Serrasalmus gouldingi in relation to fluviometric variations of lower Anapu River, in “drowned” rivers of Caxiuanã National Forest, Eastern Amazonia, Pará, Brazil. 275 specimens were bimonthly collected during July 2010 to May 2011 and their total length, total weight, gonad and stomach weight were measured. The gonads were analysed histologically to verify the sex and maturation degree, while the stomachs were evaluated through the identification of the consumed items. The sexual proportion did not differ from 1:1considering the studied period as a whole, however the females were more frequent during the transitional periods of drawdown and filing. The species spawning was “parcelada”, showing two peeks of reproductive activity during the periods which preceded the increase in the local fluviometry. The L50 was estimated in 12.24cm for males and in 16.13cm for females. The species growth was positively alometric, showing a gain of weight in relation to length, and the condition factor, when analysed along the entire sample period, decreased mostly during the spawning. The diet of S. gouldingi was composed of 32 items, grouped in 10 categories. The composition indicated an omnivorous diet with a strong tendency to piscivory, once fish fragments were the most predominant item, followed by fruits and seeds and allochthonus arthropods. The distinct hidrological periods were significantly different in relation to diet composition, although no significant difference was detected among sex and maturation degree. Males and females showed the same variation pattern of repletion index, with a more intense feeding during the increase of the river´s level, while it was less intense during the transitional periods (drawdown and filing). The species also showed some variation in their breadth niche, with lower values during the wet period, attributed to the almost exclusive consumption of fruits and seeds.
Acesso aberto (Open Access)
Avaliação de características dos regimes de umidade na flona de Caxiuanã-PA durante o experimento COBRA-PARÁ
(2010-03) TANAKA, Ludmila Monteiro da Silva; SÁ, Leonardo Deane de Abreu; MOTA, Maria Aurora Santos da
We investigate the validity of a method of humidity regimes classification, based on different "states" characterization of the Tropical Atmospheric Boundary Layer (TABL), above a forest area, according to the methodology proposed by Mahrt (1991). To perform this investigation we used radiosonde information and micrometeorological tower data collected during the drier season of the region, during the experiment "COBRA-PARÁ" (carried out from 30/10 to 15/11, 2006). The analysis of moisture regimes is based on the "phase space" data representation, where the Bowen ratio (β) is plotted against the -h/L parameter (where h is the height of the turbulent mixing layer and L is the Obukhov length scale). According to the location of the data value in this "phase space" it was possible to identify the following classes: Class I - dry air and unstable conditions, Class II - dry wind, Class III - wet wind, Class IV - wet air and unstable conditions, Class V - occurrence of water condensation on the surface, Class VI - stable conditions predominance and Class VII - dew formation generated by nocturnal radiative losses with surface cooling. Among the mentioned classes, the III, IV and VI were the most frequently observed at Caxiuanã.
Acesso aberto (Open Access)
Biologia reprodutiva e hábito alimentar de Dendrophryniscus minutus (Melin, 1941)(Amphibia : Bufonidae) na Floresta Nacional de Caxiuanã, Pará
(Universidade Federal do Pará, 2003-06) TRAVASSOS, Alessandra Elisa Melo; GALATTI, Ulisses; http://lattes.cnpq.br/1040132527458660
This study examined reproductive characteristics, nutritional status and feeding habits in the litter anuran Dendrophryniscus minutus through individuals collected in the Estação Cientifica Ferreira Pena, Caxiuanã National Forest from April 1997 to April 1998. In a sample of 166 specimens were measured snout - vent length (SVL), mass of fat bodies, diameter, mass and number of ova in females and testis volume in males. The feeding habit in this species was also determined through analyses of stomach contents. Population structure showed a pattern with most adult individuals, including gravid females, in the rainy months, and juvenile recruitment in the beginning of the dry season. Similarly, the diameter and mass ova in the mar', used as indexes of gonadal development stage, were greater in the rainy season. Among males, the biggest testis volume also appeared in february and april, but there was no evident pattern of correlation to rainfall. Food consumption also did not show any pattern in variation along months and it was not correlated to fat mass. Fat bodies measurements were positively correlated to ova development in females indicating that fat accumulation and gonadal development may occur simultaneously. The diet in specie was composed for ants, termites and mites, terrestrial invertebrates in a great number in a litter in the studied area.
Acesso aberto (Open Access)
Characterization and distribution of pyrogenic carbon in a fraction of archaeological black earth from Caxiuanã
(2015-08) MORAES, Milena Carvalho de; LEMOS, Vanda Porpino; MORAES, Dorsan dos Santos; MORAES, Cláudio Nery Lamarão
This study aims to determine the atomic ratio of O/C in an archaeological black earth (ABE) profile of the Ilha de Terra site, a region of Caxiuanã in the Pará State, Brazil, to determine the types of pyrogenic carbon (PyC) particles and to infer the source of biomass and burning temperature necessary to produce the PyC. The O/C ratios were monitored using scanning electron microscopy combined with energy dispersive spectroscopy (SEM/EDS). The results indicated atomic ratios for clay, silt and fine sand fractions that were between those registered for the PyC particles types: condensed combustion (CC) (0.09, 0.1, 0.13), charcoal (0.32, 0.31, 0.34) and char (0.43, 0.45, 0.52). CC is the predominant type of particle found because of the high firing temperature (> 350 °C), which is consistent with the probable biomass sources of wood, cellulose and lignin.
Acesso aberto (Open Access)
Distribuição espacial de anuros e lagartos ao longo de gradientes ambientais em uma floresta de terra firme na Amazônia oriental, Pará, Brasil
(Universidade Federal do Pará, 2008-08-18) GOMES, Jerriane Oliveira; ÁVILA-PIRES, Teresa Cristina Sauer de; http://lattes.cnpq.br/1339618330655263
This study aims to investigate the relationship between anuran and lizard communities, as well as of some individual species, with leaf litter depth, total basal area of trees, understorey vegetation density, and canopy cover. Sampling occurred between August and November 2007, in a 25 km² grid implanted by the ‘Programa de Pesquisa em Biodiversidade’ (Biodiversity Research Program - PPBIO) / Amazônia, located in the Floresta Nacional de Caxiuanã, Pará, Brazil. Two sampling methods were used: active search and pitfall traps with drift fences. A total of 892 lizard and anuran individuals, of 27 species (15 anuran and 12 lizard species), were recorded. Twelve anuran species (101 individuals) and 12 lizard species (171 individuals) were registered through active search, whereas 11 anuran species (327 individuals) and 15 lizard species (293 individuals) were captured by pitfall traps. No significant relationship was found between distribution of anuran and lizard communities with environmental predictors, indicating that these species occur throughout all studied environmental gradients. Only the lizards Coleodactylus amazonicus and Ptychoglossus brevifrontalis were significantly associated with understorey vegetation density and leaf litter depth, respectively. This study is expected to contribute to the improvement of the research design for the herpetofauna within PPBIO.
Acesso aberto (Open Access)
Diversidade, distribuição e estrutura da comunidade de peixes na Estação Científica Ferreira Pena: Amazônia Oriental
(Universidade Federal do Pará, 2001-11-20) MONTAG, Luciano Fogaça de Assis; BARTHEM, Ronaldo Borges; http://lattes.cnpq.br/4192105831997326
The conservation of the biodiversity in aquatic ecosystems is one of the most important and difficult challenges in the current world. According to available information, the biodiversity of aquatic ecosystems is poorly understood in comparison with tropical terrestrial ecosystems. Thus, systematic and taxonomic analyses, the understanding of phylogenetic, biogeographical and ecological relationships represent items that need to be investigated. The first question addressed is the characterization of the ecosystem. We observed that the environmental features, mainly wideness and depth, ranges spatially along the rivers and possess the inferior zone with strong characteristics of river—lake transitional areas. The following question was to estimates fishes richness of in the Ferreira Penna Scientific Station. In order to answer this question, we used protocol techniques and obtained 130 species, of these 39 were separated by morphospecies. This fact indicates that approximately 30% of the fauna might be new or there is no available bibliography for identification. The species collected in the inventory are considered to represent a reasonable set of the ichythyofauna of the region. Lastly, we aimed to characterize fish communities and expose the patterns of distribution of species concerning the investigated habitats. As a result, we observed that the com position of species in the communities followed the substitution and addition pattern. The greatest diversity of species was observed for the final zones of the rivers. The increase in the water volume and area in some habitats of the rivers makes possible their exploitation by a larger number of individuals or new species.
Acesso aberto (Open Access)
Economia madeireira: dificuldades de regulação e efeitos sobre quilombolas no arquipélago do Marajó
(Universidade Federal do Pará, 2015-04-27) SANTOS, Daiana Brito dos; ACEVEDO MARIN, Rosa Elizabeth; http://lattes.cnpq.br/0087693866786684
From the debate about regulation and institutionalization of the lumber market in the paraense Amazon with a view the data about violation of the flora of IBAMA, reports of IDERFLOR, SUDAM and a map of social cartography elaborated by quilombolas of São Sebastião Cipoal, the present study proposes to understand the State difficulty to establish the control of exploration of lumber to indicate acts of economic players in view of instrument of control, overcoat in archipelago of Marajó. See if that the positioning of state about the clandestine lumber activity is not addressed to an efficient regulation to this market, as well as it needs the efficient public politics to solve the territorial conflicts and to combat deforestation. The legal requirement of the project to forest management and to explore forest do not means that the equilibrated exploration occurs of the point of view of rational extraction the forest resource and the own use of earth reveals whether masked to " sustainability action" . Big agents with―green" seals to devastate the forest and the numbers of papers and infractions are ever higher.
Acesso aberto (Open Access)
Efeito da alteração do hábitat sobre assembleias de peixes em igarapés afogados da Amazônia oriental
(Universidade Federal do Pará, 2014-02-26) SOUSA, Híngara Leão; FERREIRA, Cristiane de Paula; http://lattes.cnpq.br/7804816854015308; MONTAG, Luciano Fogaça de Assis; http://lattes.cnpq.br/4936237097107099
The natural aquatic ecosystems are complex systems that are exposed to a variety of disturbances. In the Amazon region, for instance, land use and occupation have altered the physical structure of aquatic environments, especially regarding the small streams, influencing their communit structure and composition. This has led to research development and evaluation programs to see how the changes that are occurring in these environments affect biotic communities, through habitat characteristics that are more sensitive to disturbance. Thus, this study aimed to describe and measure physical attributes of drowned out streams and evaluate how fish assemblages respond to different levels of streams physical integrity. Our hypothesis is that structurally intact environments endure a more diverse ichthyofauna than altered environments, since their decreased environmental complexity limits the potential ecosystem, because they presented a decrease in environmental complexity. The study was conducted in 34 streams, 17 located within the territory of Caxiuanã National Forest, and 17 in its surroundings, located close to Portel and Melgaço cities (PA). The process of urbanization is expanding in the region, reaching areas of forests and streams that are still preserved. There is also an intense logging, because the area is included in the main timber pole of the estuary in the state of Pará. The physical habitat was evaluated according to a standardized protocol of stream environmental assessment. The samplings were conducted with hand nets passed along 150 meter long reaches during six hours (divided among segments and collectors). Although a set of metrics which responded to the local impact gradient has been detected these were not sufficient to reduce or increase the number of species across different levels of preservation, maintaining substantially constant the wealth and abundance for all three groups (altered, intermediate and preserved). However, the difference was significant for the composition, with eleven exclusive exclusive species of altered habitats and eight preserved environments. The degradation of the physical environment, even at smaller scales favors the occurrence and abundance of most tolerant species and phenotypic plasticity, in addition to the population increase of opportunistic species. Different effects can be exerted on the groups of species that make up a community, since they have different biological and ecological attributes that include your answers to the same ecological variables. Therefore, the possible deconstruction of community groups of species (taxonomic, functional, etc.) may show different responses to the changes of habitat, being a promising strategy for linking environmental standards of richness characteristics displayed by these communities. Assessment of biotic integrity is also an alternative to identify effects of habitat alteration on species, especially considering the region’s peculiarity and the lack of information about the local ichthyofauna.
Acesso aberto (Open Access)
Efeitos do espaço e do ambiente sobre assembleias de peixes de igarapés da Amazônia oriental
(Universidade Federal do Pará, 2012) BENONE, Naraiana Loureiro; MONTAG, Luciano Fogaça de Assis; http://lattes.cnpq.br/4936237097107099
The amazon streams have harsh environmental characteristics for several fish species due to their oligotrophic conditions. In spite of that, these watercourses possess a rich and diversified ichthyofauna, resulting from the various microhabitats found in streams. In ria lake systems, the rivers and streams suffer a natural impoundment, which provokes a lowering on current velocity values. This could homogenize the environment, since current velocity affects many of the streams features. Thereby, distance between streams could have its importance emphasized as a structural factor of stream fish assemblages. This study aimed to analyze the influence of space and environment on the structure of fish assemblages in drowned streams of Caxiuanã, in Eastern Amazon. The fishes were caught during the period of drought of 2010, including 34 transects of drowned streams. Eight abiotic factors were measured to test the effect of the environment. To analyze the effect of the space, space filters were calculated based on the geographical coordinates, as well as the distance among the streams following the watercourse. The analyses showed that the environment was the only factor to influence the beta diversity, refuting the hypothesis of the space as a structuring factor and reinforcing the paper of the ecological niche in the distribution of species. Nevertheless, the abiotic factors explained a low percentage of the variation in the fish composition, what shows that other variables can affect these assemblages.
Acesso aberto (Open Access)
Evapotranspiração regional utilizando imagens orbitais para a Amazônia Oriental
(Universidade Federal do Pará, 2012) FERREIRA JÚNIOR, Pedro Pereira; VITORINO, Maria Isabel; http://lattes.cnpq.br/4813399912998401
The evapotranspiration (ET) was spatialized using SEBAL algorithm for a region of primary forest in the eastern Amazon (Caxiuanã, Pará). To this end, we used observational data of micrometeorológica tower (located in this forest) in combination with orbital source data (Modis/Acqua images). In qualitative terms, the first results indicated that, despite the overestimation, the SEBAL plays well the pattern of variability monthly evapotranspiration for the region, mainly for the months of dry season; as to quantitative terms, the results revealed there’s need for accuracy in the algorithm. Thus, we calibrated the SEBAL from net radiation (Rn), with adjustments in the albedo, atmospheric and surface emissivity. Estimates of ET generated from this modified SEBAL presented significant improvements in reproduction of daily variability of evapotranspiration for the region, especially in the days of the rainy season. That is, the settings made in the algorithm showed that the rates of ET estimated became more similar to those reported in the literature for the Amazon, agreeing better with evapotranspiration observed. Using the modified SEBAL was can also map the albedo, net radiation, NDVI and ET for two distinct vegetation in Caxiuanã. Spatial estimation of biophysical parameters was consistently played for the two vegetation types, demonstrating that if the SEBAL modified is applied to temporal and spatial data of high resolution, this technique can be routinely used, becoming a fundamental tool in the monitoring of atmospheric and water needs.
Acesso aberto (Open Access)
Geoquímica e pedogeoquímica em sítios arqueológicos com terra preta na Floresta Nacional de Caxiuanã (Portel-PA)
(Universidade Federal do Pará, 1996-06-04) KERN, Dirse Clara; COSTA, Marcondes Lima da; http://lattes.cnpq.br/1639498384851302
The main objective of the present work is to identify the geochemical and pedological distribution patterns in archeological black earth (ABE) sites and adjacent areas, as well as, the anthropogenic action on the chemical elements responsible for the typical ABE geochemical associations. Three archeological sites were selected in the Caxiuanã region, Portel Municipality, Pará State. Trenches were excavated in these sites and in adjacent areas as well. At Manduquinha cite, the soil-horizon sampling have been carried out by collecting at each 5 m along N-S trending traverses. The archeological-material sampling has been based on an Al-horizon P2O5-distribution map on which even-spaced points have been plotted from places bearing the lowest and the highest P2O5 concentrations. For each of these points, chemical and mineralogical analyses have been made aiming at the following determinations: a) mineralogical composition by X-ray diffraction; b) SiO2, TiO2, Fe2O3, P2O5 (Al2B4O7), Al2O3, Na2O, K2O, CaO, MgO, Cd, Co, Cu, Mn, Pb, and Zn (HF + HC1PO4 total dissolution), and C (modified Walkley-Black method), by atomic absorption, colorimetry, and titration; c) As, Se (hydrides), Hg (vapor), Zn, Mn, and Fe (NH4 oxalate + oxalic acid), sorptive ion-complexes (NH4 acetate at pH 7.0), by atomic absorption; d) Cr, B, V, Sc, by optical-ernission spectrochemical analysis, U, by fluorometry, and F by specific-ion electrode analysis; e) Ba, Cl, Ga, Nb, Sr, Y, and Zr by X-ray fluorescence; f) qualitative chemical composition of ceramic and sou by means of scanning electron microscopy; and, g) radiocarbon (C") dating of ceramic artifacts. From a geological point of view, the Caxiuanã region is made up of sediments belonging to Alter do Chão Formation which have been laterized in Tertiary. Ironstones also occur in that region, outcropping at the bay water level and, sometimes, they were used as abrasive material by the prehistoric man. The main drainage system is constituted by the Caxiuanã bay and the Anapu river. Yellow latosol predominates compared with lateritic profiles; hydromorphic soils also occur at the lower portions. The ABE occurrences, known as archeological sites, are found in the higher portions of the latosol domain and are characterized by a dark-colored soil and by the presence of numerous ceramic fragments and lithitic artifacts. In comparison with the adjacent areas, the ABE's A-horizons, besides exhibiting a dark color, are sandier and structurally better organized. Their bases exchange_sum, cation exchange capacity, base saturation, and pH values are higher than those of the adjacent soils, being thus more fertile than the other ones are. The B horizons do not show significant changes regarding their morphological, physical and chemical aspects both in ABE's and adjacent arcas. The chemical composition essentially constituted by SiO2, Al2O3, Fe2O3, and TiO2 is consistent with the described mineral assemblage which comprises quartz, kaolinite, ghoetite, and anatase, The ABE's A-horizon, compared with the B horizon, presents higher contents of SiO2, MgO, CaO, P2O5, C, Ba, Cl, Cu, K, Mn, Sr, and Zn; and lower values of Al2O3, Fe2O3, Na2O, As, Cd, Co, Ga, Cr, F, Pb, Se, and V, that is the first group got enriched and the second one depleted in these elements. Some elements such as Nb, Hg, and Zr do not show significant relative variations from ABE to adjacent areas. In Manduquinha site, soil morphologic features allowed the separation of the ABE's into N and S domains. Due to the fact of being at a slightly lower topographic level, the S-dornain generates an anaerobic microenvironment during the rainier season. The geochemical distribution of the elements in the A, horizon reflects the environmental changes which took place in ABE's. The S-domain is enriched in Si, Mg, P, Ba, Cl, Cu, K, Mn, Sr, and Zn; and presents lower concentrations of the remaining elements, The geochemical data treated through R-type cluster analysis, isocon maps, and factor analysis allowed the identification of three major geochemical associations and their respective concentration areas. 1) P2O5, MgO, CaO, Ba, Cu, Cl, Mn, Sr, and Zn represent the elements, closely related to the ABE's, which have been added to soil; 2) Fe2O3, Na2O, As, Cd, Co, Cr, F, Ga, Pb, and V correspond to the regional latosol geochemical signature which has indirectly been modified by the prehistoric human activity in the site; e, 3) B, Hg, Nb, Sc, Y, and Zr also constitute the regional latosol geochemical signature although they have not undergone significant changes in consequence of the past human occupation. Manduquinha site has been occupied by the prehistoric man during a period of at least 300 years (1280 to 1600 AD). Characteristics of their ceramic manufacture such as the use of antiplastic materials as well as burning and ornamentation techniques corroborate the hypothesis of cultural continuity. The occupation by the people which inhabited that place may have been contínuos or not. In both cases, the small ABE's surface extension (0.5 ha), the shallow depth of the anthropogenic-modified bed, and the small amount of archeological material suggest an occupation with low population density. The cultural habit of disposing organic leavings at separated places led to a significant increase in P, Ba, Ca, Cl, Cu, K, Mg, Mn, Sr, and Zn in the ABE's. The elevated Ca contents at the southwestern limit may be accounted for remains of shells, commonly found in the form of pockets in other archeological cites in the region. In the west- and northwestern ABE's parts there has been a greater addition of materials Mg- and P-rich in such as bones, feces, urine etc., while in the southeast- and northeastern portions it has been observed predominance of Zn-, Mn-, and Cu-rich materials. In the northern part, where the soil is more compact, and at the central portion as well, the occurrence of lower contents of the above-mentioned elements is interpreted to be a consequence of the localization of circulation areas of the group. The pedogenetic processes, which took place after the prehistoric human occupation, related to the own ground surface conformation favored a stronger leaching of P, Ba, B, Ca, Cl, Cu, K, Mg, Mn, Sr, and Zn which concentrate at the extreme-south, in the adjacent area Fe2O3 and associated elements are found in greater concentrations in the northern part with clear dispersion southward.
Acesso aberto (Open Access)
História natural do lagarto partenogenético Leposoma percarinatum (Squamata: Gymnophthalmidae) em floresta amazônica, Pará, Brasil
(Universidade Federal do Pará, 2012) DIAS, Dina-Mara; COSTA, Maria Cristina dos Santos; http://lattes.cnpq.br/1580962389416378
To understand the ecological role that each species play in their habitat, basic studies of natural history, involving questions about habitat use, trophic and reproductive ecology, are necessary. Aiming to characterize the activity, microhabitat use, diet and reproduction patterns of a population of Leposoma percarinatum (Muller, 1923), we analyzed individuals collected in two areas of the “Floresta Nacional de Caxiuanã” (PPBio and ECFPn), on the municipalities of Melgaço and Portel, Pará state. In order to do that, we analyzed the composition and importance of food items, microhabitat use, period of activity, reproductive cycle and fecundity of the species. L. percarinatum is a component of the humid leaf litter near water bodies. It is a diurnal species of lizard, with period of actibvity between 0800h and 1700h. With a generalist feeding habit, it feeds on arthropods, with Hymenoptera, Coleoptera and Araneae being the most important items, without significant differences on the alimentary index between dry and rainy season. It has a continuous reproductive cycle and the clutch size is up to two eggs, where larger females tend to produce larger eggs.
Acesso aberto (Open Access)
História natural e ecologia das serpentes da Floresta Nacional de Caxiuanã e áreas adjacentes, Pará, Brasil
(Universidade Federal do Pará, 2008) MASCHIO, Gleomar Fabiano; MARTINS, Marlúcia Bonifácio; http://lattes.cnpq.br/8882047165338427; PRUDENTE, Ana Lúcia da Costa; http://lattes.cnpq.br/1008924786363328
The search for patterns of community structure and composition is essential to provide information which allows the sustained management of species populations and monitoring of antropic activities. Despite the fact that Neotropical region harbors an enormous diversity of species and complex ecological interactions, very little information is available on snake assemblages. Therefore, the processes responsible for community organization are not well understood. In Brazil, several studies were conducted to analyze the factors responsible for the patterns of distribution and interactions among snake species. In order to identify the factors that determine those patterns and which affinities (ecological and or historical) those species share, a study of the local taxocenose of snakes was performed in the Floresta Nacional de Caxiuanã and adjacent areas, from 2005 to 2006. Four sampling methods were used employed: time constrained search, local collectors, incidental encounters, and pitfall traps with drift fences, in five areas (IBAMA and Caquajó in the Floresta Nacional de Caxiuanã; Marinaú, Enseada and Mojuá located in adjacent areas to the Floresta Nacional de Caxiuanã). A total of 378 specimens of snakes within five families, 35 genera and 50 species were registered. Considering the records of species obtained in this study and those from previous studies, the local number of snake species increases from 63 to 69 species. The methods that best revealed the number of individuals were time constrained search (199/378) and local collectors (159/378). Incidental encounters (11/378) and pitfall traps with drift fences (9/378) were less representative. The estimated richness (Jackknife 1) from PLT data was 56 (+or– 4) species. The composition of snake species in the studied area shows higher similarity with taxocenoses of other Amazon areas. Most abundant species, as revealed by time constrained searches, were Imantodes cenchoa, Corallus hortulanus and Leptodeira annulata. All methods showed Bothrops atrox, Imantodes cenchoa and Corallus hortulanus as most representative. The areas under high antropic pressures located out of the National Forest showed lower abundance and richness when compared to protected areas in there. Nine potentially specialist species were recorded: Lachesis muta (small mammals), Atractus schach (earthworms), Dipsas catesbyi (mollusks), Helicops trivitatus and Hydrops triangularis (fish), Siphlophis compressus (lizards), Xenopholis scalaris, Taeniophallus brevirostris (anuran) and Tantilla melanocephala (centipedes). The items most frequently consumed were lizards, anurans and small mammals. The snake species primary or exclusively diurnal represent the larger percentage. Most species analyzed present non seasonal reproductive period, possibly as a result of no significant differences in the mean temperature throughout the year. The taxocenose of snake species in the Floresta Nacional de Caxiuanã and neighboring areas is formed by groups of species that share similar patterns of feeding and daily activities. Besides several ecological factors such as temperature and pluviometric averages and biome structure, historical factors (such as morphological adaptations of snake species) influence on sbake taxocenose composition in the Floresta Nacional de Caxiuanã and adjacent areas. Thus, more studies on the ecology and natural history of snakes must be continuously conducted in order to characterize novel patterns of distribution of snake species in different biomes.
Acesso aberto (Open Access)
Inventário da araneofauna (Arachnida, Araneae) de serapilheria na Estação Científica Ferreira Penna, Pará, Brasil
(Universidade Federal do Pará, 2004-03-02) BARREIROS, José Augusto Pereira; BONALDO, Alexandre Bragio; http://lattes.cnpq.br/8721994758453503
The Ferreira Penna Scientific Station (ECFP), with near 33.000 ha, is located at Caxiuanã National Forest, Pará state, Brazil. A structured protocol of ground litter spiders sampling resulted in 400 samples of 1m² concentrated litter, from both rainy and dry seasons. The spiders were sorted by a combination of manual sorting and Winkler device techniques. These samples were obtained in five plots, three located in Terra Firme (dryland) forest (LBA-EXP, LBA-CON and TF-IMC) and two in igapó (wetland) forest (IG-N and IG-S). One of the Terra Firme plots (LBA-EXP) is under hidric stress and it was used plastic panels and gutters to exclude most of the rainfall. A total of 2230 individuals (mean: 5,6 individuals / m²), beionging to 34 families, were collected. Seven families were represented only by juveniles: Nesticidae, Pisauridae, Gnaphosidae, Mimetidae, Deinopidae, Oxiopidae, Uloboridae. The most abundant families were Salticidae, Theridiidae, Ctenidae, Oonopidae and Linyphiidae. 876 adults, beionging to 120 species or morphospecies in 27 families were sampled. The most abundant species were Styposis sp.3 (Theridiidae), with 16,55% of all adults, Anapisona sp.1 (Anapidae), with 6,96%, Meioneta sp.1 (Linyphiidae), with 6,39%, Oonopidae sp.1, with 5,59% and Salticidae sp.1, with 4,56%. In order to implement the majority of the analysis, 15 occasional species were excluded. The observed species accumulation curves for all samples and for the samples from each plot didn't reach the asymptote in the end of samples addition. The patterns of abundance and incidence of these species suggest the existence of total species richness from 123 to 184 species. The largest species richness estimates were from plot LBA-EXP (75 - 110 species). The smallest ones were observed at plot IG-N (25 - 59 species). Despite the species richness and the abundance of spiders had reached the largest values at plot LBA-EXP, the overall diversity was larger at plots LBA-CON and TF-IMC. The Igapó overall diversity was lower than in Terra Firme. The species composition was different in Terra Firme and Igapó habitats, as demonstrated by similarity indexes and percentage complementarity. The abundance and species richness of litter spiders increased in dry period and decreased with the raising of soil residual humidity.
Acesso aberto (Open Access)
A new Amazonian species from the Drosophila annulimana species group (Diptera, Drosophilidae)
(Universidade Federal do Pará, 2012-12) GOTTSCHALK, Marco Silva; MARTINS, Marlucia Bonifacio; PRAXEDES, Catarina de Lurdes Bezerra; MEDEIROS, Hermes Fonseca de
Drosophila caxiuana sp. nov., Drosophila subgenus, is described and illustrated. This new species was collected in the Amazonian Biome (Caquajó river, Portel, Pará, Brazil) and is an atypical species to the group due the unusual morphology of the male terminalia.
Acesso aberto (Open Access)
Síndrome metabólica e fatores associados em populações da Amazônia oriental brasileira: um estudo transversal
(Universidade Federal do Pará, 2015-08-28) FRANÇA, Sergio Lobato; VIEIRA, José Ricardo dos Santos; http://lattes.cnpq.br/1720718046686259
Acesso aberto (Open Access)
Sobreposição de nicho de duas espécies simpátricas de Arthrosaura (Squamata: Gymnophthalmidae), na Floresta Nacional de Caxiuanã, Pará
(Universidade Federal do Pará, 2012) SILVA, Kleiton Rodolfo Alves da; COSTA, Maria Cristina dos Santos; http://lattes.cnpq.br/1580962389416378
In general, species with phylogenetic relationship use resources in similar ways and can be potential competitors. However, they can diverge in one of the three axis of the ecological niche; it may be at temporal axis, spatial and/or trophic axis. Those differences can be determinant for the existence of these populations. Assuming that these populations of Arthrosaura have had contact and that maybe has niche overlap, which strategies these species use to minimize the competition? Based on that, this study has the aim to investigate the spatial, temporal and trophic niche of these populations of Arthrosaura kockii e Arthrosaura reticulata in two sites at Caxiuanã’s National Forest. This is located between Melgaço and Portel county, Pará state, Brazil. Where were made three expeditions. The specimens were collected with the active search mode that began at 06:00 hours a.m and ended at 18:00 hours. Were collected data on 107 of A. kockii and 115 of A. reticulata of these, 107 and 113 had prey items in the digestive system, respectively. Stomachs were removed and the prey items were separated carefully and after were identified at the lowest taxonomic level. Were counted 26 prey items, which 25 were consumed by A. reticulata and 14 by A. kockii. Arthrosaura reticulata has a bigger niche breadth at the raining months and transitional months, A. kockii has a bigger niche breadth at the raining months and at drier months. The most important prey items consumed by A. reticulata were Araneae, Blattaria, Orthoptera-Gryllidae and Homopera, for A. kockii were Araneae, Blattaria, Orthoptera-Gryllidae and Isoptera. A. reticulata has a longer activity period initiating at 07: 50 am and ends at 5 pm, and has its peak of activity was between 09:00 hours and 14:30 hours. This specie was considered non-heliotherm. A. kockii had a smaller activity period, starting at 08:40 hours and ending at 15:25 hours and its peak of activity was between 10:00 hours and 14:30 hours. This specie was considered heliotherm. A. reticulata was found at the leaf litter with height between 2.5 cm and 13 cm, above and below this it was not found. A. kockii was found at the leaf litter with height between 1.5 cm and 10 cm, above and below those values it was not found. A. reticulata was found at many forest environments, near the water at low forest and at the terra firme forest, but A. kockii was only found at the terra firme forest. The deepness of the leaf litter and the distance from the water were important to the species distribution.