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Acesso aberto (Open Access)
Conforto ambiental de bezerros bubalinos (Bubalus bubalis Linnaeus, 1758) em sistemas silvipastoris na Amazônia Oriental
(Instituto Nacional de Pesquisas da Amazônia, 2010-12) MORAES JUNIOR, Raimundo José; GARCIA, Alexandre Rossetto; SANTOS, Núbia de Fátima Alves dos; NAHÚM, Benjamim de Souza; LOURENÇO JÚNIOR, José de Brito; ARAÚJO, Cláudio Vieira de; COSTA, Norton Amador da
This aim of the study was evaluating effects of two different silvopastoral systems on environmental comfort and changes in physiological parameters of buffalo calves bred in the Eastern Amazon. The experiment was conducted at Embrapa Amazônia Oriental, Belém-PA, (Afi climate type) in two periods of the year: Period 1 (April to Sep/2007) and Period 2 (Oct/2007 to March/2008). Eleven calves were included in the Silvopastoral System 1 (SSP1), with a useful shaded pasture area of 18 to 21%; and eight calves were included in the Silvopastoral System 2 (SSP2), without shading, but with a lake for swimming. Physiological status of animals bred in the two SSP's were measured (rectal temperature-RT; respiratory frequency-RF and skin temperature-ST). The Temperature and Humidity Index (THI) and Benezra´s Animal Comfort Index (ACI) were calculated, in two phases of the year, and were compared by the Tukey test (P < 0.05). THI ranged from 73.5 ± 1.3 to 82.2 ± 0.8. RT was 38.3 ± 0.26 to 39.3 ± 0.38 °C, but within the normal range for buffalo. RF ranged from 32.2 ± 9.2 to 56.5 ± 19.0 mov min-1, above the levels considered normal, and ST ranged from 23.6 ± 8.3 and 31.7 ± 5.4 °C. In both periods of the year and the two SSP's, ACIs were considered higher than ideal, ranging from 2.46 ± 0.33 to 3.31 ± 0.62 (SSP1) and 2.42 ± 0.30 to 3.45 ± 0.66 (SSP2).
Acesso aberto (Open Access)
Dispersão geoquímica dos elementos Si, Al, Fe, Mn, Na, K, Cu e Zn nos solos e sua aplicação na caracterização de áreas geoquimicamente homogêneas
(Universidade Federal do Pará, 1980-05-13) SILVA, Waldise Rossycléa Lima da; RONCAL, Juan Rolando Zuleta
Variations in the chemical composition of soils are used to characterize sub-areas geochemitally homogenous. The aplication of this methodology in a tropical humid region of accentuated topography constitute the principal objective of the present research. Samples of red latosols (Horizon B) developed over gravite, sandstone and basalt occurring in the Central Granite Region of the Serra dos Carajás, Pará State, Brasil were analized for the elements Si, AL., Fe, 40Mn, Na, K, Cu e Zn, by atomic absorption spectrophotometry. Based on the criterion of similarity in the chemical composition (Cluster Analysis, Factor Analysis) the soils were separeted in to different groups. The geographical distribution of the different groups permit the establishment of a Glose relationship between the different parent lithologies and their corresponding soils.
Acesso aberto (Open Access)
Ecologia da ictiofauna do estuário do rio Paciência, Ilha do Maranhão - Brasil
(Universidade Federal do Pará, 2012-02-23) SILVA JÚNIOR, Milton Gonçalves da; CASTRO, Antonio Carlos Leal de; http://lattes.cnpq.br/9450410023114396; SAINT-PAUL, Ulrich; http://lattes.cnpq.br/5897104750785224
Estuarine systems constitute an important habitat for different species of fish. From the ecological standpoint, the ichthyofauna plays an important role in the energy balance between trophic levels in estuarine ecosystems. Thus, the following were aims of the present study: determine the spatiotemporal distribution of the ichtyofauna; explain behavioral and ecological characteristics; compare the composition of relative biomass, ecological and functional guilds in different estuarine systems in northern Brazil; investigate the influence of biotic and abiotic variables and correlations with the biological patterns of the ichthyofauna; and identify changes in the biotic integrity of the tidal creeks studied. Data were acquired through bimonthly sampling in the Iguaiba, Grande and Cristovao tidal creeks between January 2006 and September 2007, using gillnets and block nets. Samples were also taken of the surface water for the determination of physicochemical parameters and dissolved inorganic nutrients. Diversity, evenness and richness indices were employed for the ecological characterization of the species. The biotic integrity index was used to assess the effects of possible environmental changes on the ichthyofauna. Univariate (ANOVA, Kruskall-Wallis) and multivariate (Cluster, nMDS, SIMPER, COIA and ABC curves) statistical methods were used to compare species and capture sites. A total of 12,219 individuals distributed among 55 species and 27 families were caught. The families Sciaenidae, Ariidae, Carangidae, Engraulidae and Mugilidae had the greatest species richness. Ariopsis bonillai and Cetengraulis edentulus made the greatest contribution to the formation of similar groups. Stellifer naso and Cynoscion acoupa were responsible for the dissimilarity between the groups formed. Approximately 66% of the fish caught were juveniles, thereby confirming the use of estuarine systems as nurseries. The records between the Marajoara and Maranhao Gulfs indicate the occurrence of 140 species. Marine occasional visitors and freshwater species occurred occasionally. Marine estuarine-opportunists and estuarine dependents species made the largest contribution to the Maranhão Gulf, whereas estuarine residents species had high biomass values in all estuarine systems investigated. Detritivores occurred mainly in the state of Para and zoobenthivores were found mainly in the state of Maranhao. The occurrence of piscivores was inversely proportional to the abundance of juveniles. The co-structure formed between environment-fish parameters was significant. Salinity, pH, silicate, ammonium, phosphate and nitrate exerted an influence over the structure of the fish community. No species were associated with environments with high concentrations of inorganic nutrients. The ABC curves revealed that the estuarine environment is moderately disturbed and the integrity index characterized the environmental quality of the tidal creeks as very poor to fair. The presence of juveniles demonstrates the importance of tidal creeks to fish development. The ichthyofauna analyzed in the present study exhibits seasonality with regard to hydrological periods. The fish community in tidal creeks can serve as an indicator of the quality of ecosystems submitted to tidal pulses. Therefore, the protection of tidal creeks in mangroves is essential to the management of fishery resources, considering the strong association between ichthyofauna abundance and the structural composition of the habitat.