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Belowground Carbon and Nitrogen on a Thinned and Un-Thinned Seasonally Dry Tropical Forest  [PDF]
Deodato do Nascimento Aquino, Eunice Maia de Andrade, Andréa Dardes de Almeida Castanho,cio Resende Pereira Júnior, Helba Araújo de Queiroz Palácio
American Journal of Plant Sciences (AJPS) , 2017, DOI: 10.4236/ajps.2017.89140
Abstract: The aim of this study was to quantify the dynamics of herbaceous biomass and fine root productivity, and their relationship to stocks of carbon and nitrogen, in the Vertisols of two adjacent watersheds of a seasonally dry tropical forest (SDTF) under two different types of ground cover. The two watersheds are located in the county of Iguatu in the State of Ceará, Brazil. The control watershed of 2.1 ha, has been under regeneration for 35 years (RC35), while the second watershed (1.1 ha) was subjected to thinning for a period of 5 years (TC5). The sampled variables were herbaceous shoot biomass, fine roots, gravimetric moisture, the isotope δ13C (‰), total soil carbon (TSC) and total nitrogen (TN) in the 0 - 20, 20 - 40 and 40 - 60 cm layers, between April 2013 and March 2014. To quantify herbaceous shoot biomass, samples were taken monthly. For TSC and TN, the campaigns were held every two months. The data underwent analysis of means and were compared by t-test (p < 0.05). Under TC5, there was an increase in the stocks of TSC and TN of 151 and 137% respectively in the 40 - 60 cm layer, in relation to RC35. The implementation of thinning in a SDFT is seen as a management alternative to be considered in sustainability programs in the semi-arid region, contributing to maximising the production of herbaceous forage for feeding large and small ruminants, and for bee pasture, in addition to increasing the stock of carbon in the soil of SDFT and reducing global warming.
Sediment loss in semiarid small watershed due to the land use Produ o de sedimentos em microbacias hidrográficas semiáridas sobre manejos diferenciados
Joseilson Oliveira Rodrigues,Eunice Maia de Andrade,Helba Araújo Queiroz Palácio,Luiz Alberto Ribeiro Mendon?a
Revista Ciência Agron?mica , 2013,
Abstract: The aim of this study was to evaluate and compare the sedimentological behavior in two small rural watersheds in the semiarid Northeast of Brazil, examining the influence of human activity on the sediment yields. The studied area is sited in the Alto Jaguaribe basin, more precisely in the Iguatu County, Ceará State. The experimental area was composed of two small watersheds denominated B1 and B2. In watershed B1 a treatment (thinning) was applied, eliminating the plant species with diameters lower than 10 cm. The results showed that the Caatinga clearing practice did have an influence in changing the sediment yield during the first events. It was also found that the magnitude of previous events contributed to an increase in the sediment yields by the subsequent events as a consequence of the sediment deposit in the drainage network. The accumulated sediment yields reached at the end of the 2009 rainfall season values of 1.45 and 1.39 tons ha-1 year-1 for B1 and B2, respectively, with no significant difference at 5%. It was concluded that, even when the effect of treatment on the sediment yields at the beginning of the rainy season is measured, the total sediment yields was not changed by the adoption of clearing. Therefore, it is a management system that can be employed in the land use at semiarid regions. O objetivo central deste trabalho foi avaliar e comparar o comportamento sedimentológico em pequenas bacias rurais no semiárido nordestino, verificando a influência da a o antrópica sobre a produ o de sedimentos. O estudo de caso foi conduzido em duas microbacias adjacentes e com uso da terra distintos. Estas est o localizadas no Bioma Caatinga, no semiárido do nordeste do Brasil. Em uma microbacia (B1) foi aplicado um tratamento (raleamento), eliminando-se as espécies vegetais com diametro inferior a 10 cm. A segunda microbacia experimental (2) foi mantida com sua cobertura vegetal original, que n o é explorada há 30 anos. Os resultados revelaram que a prática de raleamento da Caatinga teve influência na altera o da produ o de sedimentos durante os primeiros eventos. Verificou-se também que a magnitude dos eventos anteriores contribuiu para aumento na produ o de sedimentos pelos eventos subseqüentes em conseqüência da deposi o de sedimentos na rede de drenagem. A produ o acumulada de sedimentos atingiu ao final do período chuvoso de 2009 valores de 1,45 e 1,39 ton ha-1 ano-1 para as microbacias B1 e B2, respectivamente, n o apresentando diferen a significativa ao nível de 5%. Conclui-se que, mesmo sendo constatado o efeito do tratamento sobre
Runoff and soil and nutrient losses in semiarid uncultivated fields
Santos, Julio Cesar Neves dos;Palácio, Helba Araújo de Queiroz;Andrade, Eunice Maia de;Meireles, Ana Célia Maia;Araújo Neto, José Ribeiro de;
Revista Ciência Agron?mica , 2011, DOI: 10.1590/S1806-66902011000300030
Abstract: although water erosion is the principle agent responsible for soil degradation, field data on the impacts of erosion, due to high operational costs and measurement difficulties, are scarce, especially in semiarid regions. in this context, the aim of this study was to evaluate runoff and soil and nutrient losses in uncultivated areas in the semiarid region of the state of ceará in brazil. the experiment was conducted in a 20 m2 erosion plot that was uncultivated and populated with herbaceous plants. data were collected during the rainy season from january to may 2009. monthly water losses from overland flow ranged from 3.4 to 168.9 mm, representing 1.8 to 42.3% of the total monthly rainfall for january and april, respectively. soil loss from erosion totaled 2,166.6 kg ha-1. in february, soil losses were 834.3 kg ha-1, corresponding to 38.5% of the total value. the rainfall erosivity index (ei30) was 5,716.4 mj mm ha-1 h-1. the observed high variability of soil losses in individual events was influenced mainly by the antecedent soil water content. although this study used only one year of observations, the findings are important for land use planning, especially in the semiarid region of brazil, where datasets are scarce.
Similaridade da qualidade das águas superficiais da bacia do Curu, Ceará
Palácio, Helba Araújo de Queiroz;Andrade, Eunice Maia de;Lopes, Fernando Bezerra;Alexandre, Deborah Mithya Barros;Arraes, Francisco Dirceu Duarte;
Ciência Rural , 2009, DOI: 10.1590/S0103-84782009000900017
Abstract: a special attention should be devoted to the water quality determinant factors, since the water supply has been decreased each year. the aim of this research was to define the similarity of determinant variables of water quality in the perennialized part of the curu watershed, ceará, brazil. multivariate analysis/cluster analysis was used for this investigation and it was proceeded during the wet and dry season. the samples were took in seven stations, spreading out along the rivers during four campaigns of collection (january, march, may and august of 2005), totalizing 28 samples. the water attributes analyzed were: ph, ce, ca2+, mg2+, na+, k+, cl-, co3-, hco3-, so4-, po43-, nh4- and no3-. four homogeneous groups were identified. they were independent of their geographic position. they were identified expressing the influence of weather seasonality. the values of sodium adsorption ratio (ras) defined the dissimilarity of group 1 in relation to the others. the values of nitrate and phosphorus defined the similarity of group 2; while the electric conductivity (ce), ras, sodium and chloride ions determined the non homogeneity between groups 3 and 4. although the salinity level of water (ce>0,5d sm-1) was not suitable to human consume, the na+ and cl- concentration do not present risks to human health. in relation to irrigation, only one group presented salinity risk from low to moderate, while sar showed the same risk level for all groups.
Land use and the hydro-sedimentological response of a watershed in a semiarid region. = Uso da terra e resposta hidrossedimentológica de microbacia no semiárido
Helba Araújo de Queiroz Palácio,José Ailton da Silva Filho,Eunice Maia de Andrade,Julio César Neves dos Santos
Agro@mbiente On-line , 2012,
Abstract: In northeastern Brazil, with its semi-arid climate and an environment full of contrasts, side by side with the intensive exploitation of the natural resources by agricultural companies, it can be seen both agricultural and livestock farming being practised by small-holders as a way of earning their living. This exploitation is generally unsustainable, resulting in a scarcity of land and water resources, and having serious negative effects on this region. The objective of this research was to analyse the influence of anthropic action on the hydro-sedimentological responses of an experimental watershed with transitory drainage, located in the semiarid region of Ceará, during the years under study of 2009 and 2010: the catchment area of theobserved watershed being 2.8 ha. In 2009, the first year of the study, the native caatinga vegetation of the area was maintained unaltered; the following year a type of land use common to the region was applied, consisting of the removal of all vegetation followed by burning the land and cultivation of the grass Andropogon gayanus Kunt for the production of pasture. The rainy season of 2009 presented a total rainfall of 1,063 mm, 23.1% of the total precipitation being converted to surface runoff and resulting in a sediment yield of 730 kg ha-1. In 2010, due to the lower volume precipitated (809 mm), total runoff corresponded to 13.9%, but the sediment yield was maximized, with a total of 2,832 kg ha-1, this being 72% higher than in the previous year and demonstrating the negative effect of applied management. = Na regi o Nordeste do Brasil, com clima semiárido e ambiente de contrastes, verifica-se lado a lado a explora o intensiva dos recursos naturais por empresas agrícolas e a agricultura e pecuária praticada por pequenos produtores como forma de garantir a subsistência. Estas explora es ocorrem na grande maioria de forma insustentável, resultando na escassez dos recursos solo e água com sérios reflexos negativos nessa regi o. Objetivou-se com esta pesquisa analisar a influência da a o antrópica sobre as respostas hidrossedimentológicas em microbacia experimental de escoamento efêmero no semiárido cearense durante os anos de 2009 e 2010. A área de drenagem da microbacia estudada é de 2,8 ha. No primeiro ano de estudo (2009) a área foi mantida inalterada com vegeta o de caatinga nativa e no ano seguinte foi aplicado um tratamento de uso do solo comum na regi o, que consta de supress o da vegeta o, seguida de queimada e cultivo de gramínea Andropógon gayanus Kunt para a produ o de pastagem. A esta o chuvosa de 200
The water quality investigation using GIS and multivariable analysis in a semiarid region reservoir
Alexandre, Deborah Mithya Barros;Andrade, Eunice Maia de;Lopes, Fernando Bezerra;Palácio, Helba Araújo Queiroz;Ferreira, Andrea Cristina da Silva;
Revista Ciência Agron?mica , 2010, DOI: 10.1590/S1806-66902010000400007
Abstract: this study was carried out in the serrote reservoir, sited in the groaíras watershed at the northeastern region of ceará state, brazil. the aim was to investigate the temporal and spatial variability of water quality. data investigation was processed using multivariate analysis/cluster analysis and gis techniques. samples were taken in four stations spreading out over the water body during five campaigns of collection (february, may, august/2007 and may, august/2008). the water quality parameters analyzed were: electric conductivity (ec), ph, dissolved oxygen (do), temperature, chlorophyll 'a' concentration and total phosphorus (tp). two homogeneous groups were identified, which expressed the inter-annual seasonality influence in the water quality. the highest concentration of investigated attributes occurred in 2008. at that year, the depth of the annual rainfall was 53% above the annual average. chlorophyll 'a' and total phosphorus defined the dissimilarity between the two groups. group 1 was composed with the better water quality and concentrations of attributes were close to the recommended limit defined by resolution 357/05 of conama. whereas group 2 presented average concentrations of chlorophyll 'a' and total phosphorus two times greater than the ones registered in group 1, there for been above the limit established by conama (357/05) for human consumption. the reservoir presents characteristics that point toward eutrophization due to the use and management of the soil around said reservoir.
Land use and groundwater quality: the case of Baixo Acaraú Irrigated Perimeter, Brazil
Andrade, Eunice Maia de;Lopes, Fernando Bezerra;Palácio, Helba Araújo Queiroz;Aquino, Deodato do Nascimento;Alexandre, Deborah Mithya Barros;
Revista Ciência Agron?mica , 2010, DOI: 10.1590/S1806-66902010000200006
Abstract: the aim of this work was to identify and to investigate the determining factors of water table quality in the irrigated perimeter of baixo acaraú, ceará, brazil, using factor analysis/principal component analysis (fa/pca). it was sampled nine shallow wells spread out on two different types of land: uncultivated area (a1) and irrigated area (a2). groundwater was sampled monthly from dec/2003 to nov/2005, nov/2006, mar and april/2007. we measured the following parameters: ph, electrical conductivity (ec), and concentrations of na+, ca2+, mg2+, k+, cl-, po4-, nh4-, no3-, so4-2, hco3- and co3- 2. the pca resulted in a model composed of three components that explained 93.06% and 83.72% of the total variance of the data set from a1 and a2, respectively. it was found that the determining factors of water quality were the mineralization processes and anthropogenic activities in both areas. the anthropogenic activities in the irrigated area were related to nitrogenous fertilizers, while those in the uncultivated area were associated with the presence of septic tanks (from the lack of sewage treatment).
Crescimento de bananeiras sob diferentes níveis de salinidade da água de irriga??o
Carmo, Gilcimar Alves do;Medeiros, José Francismar de;Tavares, José Celesmário;Gheyi, Hans Raj;Souza, Ana Maria de;Palácio, Elba Araújo de Queiroz;
Revista Brasileira de Fruticultura , 2003, DOI: 10.1590/S0100-29452003000300038
Abstract: the effects of different salinity levels of irrigation water (s1 = 0.55 ds/m, s2 = 1.70 ds/m, s3 = 2.85 ds/m e s4 = 4.00 ds/m) on vegetative growth in bananas pacovan (aab) and marmelo (abb) were evaluated. the experiment was carried out on a sandy clay loam chromic argisol in a split-plot scheme arranged in a randomized block design with four replications. the whole plots were composed of a row with 10-plants, five plants of each cultivar (subplot), and the data were collected from the three central ones. the irrigations were applied either dayly or every each two-days period in order to maintain a lixiviation fraction of 0.15, using approximate water sheets to keep the soil at field capacity. the data obtained at 110, 160, 220, 300, and 360 days after planting indicated that the water salinity level increase caused plant height, number of leaves, and leaf area to decrease significantly up to 240 days of the growth period, with the values becoming equalled after the rainy period.
Deposi o e decomposi o de serapilheira em área da Caatinga. = Litter productivity and deposition in area of Caatinga.
José Fredson Bezerra Lopes,Eunice Maia de Andrade,Francisco Antonio de Oliveira Lobato,Helba Araujo de Queiroz Palácio
Agro@mbiente On-line , 2009,
Abstract: Para avaliar a deposi o e a taxa de decomposi o da serapilheira em área da Caatinga, bem como,verificar a interferência de variáveis climáticas, desenvolveu-se um estudo em quatro microbacias localizadas no município de Iguatu, Ceará, Brasil. A produ o de serapilheira era coletada mensalmente (mai/2007 a set/2008) em 20 caixas de 1,0 m2, separando-se em seguida as fra es: folhas, estruturas reprodutivas, galhos e miscelanea. Coletou-se, trimestralmente, a serapilheira circunscrita sob um quadrado de ferro de (0,5 m x 0,5 m), estimando-se em seguida a serapilheira armazenada sobre o solo; a massa seca de serapilheira foi obtida pela secagem em estufa a 70oC até peso constante. Foram coletadas amostras de solo (0-15 cm) para se obter a umidade. Observou-se que entre as espécies arbustivo-arbóreas, apenas duas (Aspidosperma pyrifolium Mart. e Croton sonderianus Muell. Arg.) representam mais de 50% da popula o e a cobertura vegetal é determinada pelo estrato herbáceo, já que apresenta um número bem maior de plantas. A produ o de folhas apresentou uma estreita rela o com o regime pluviométrico, sendo seu ápice logo após a quadra chuvosa, enquanto a produ o de estruturas reprodutivas foi determinada pelas espécies. A deposi o da serapilheira apresentou caráter sazonal com uma produtividade de 2.855,42 kg ha-1, e picos de produ o imediatamente posterior a quadra chuvosa. Já a decomposi o da serapilheira mostrou-se relativamente lenta, com uma taxa de decomposi o (K) inferior a 1. = This work evaluated the litter accumulation and decomposition in a Caatinga, as well as to verify the climate variable influence. Field work was carried out at four small watershed sited in the Iguatu County, Ceará, Brazil. Litter productions were estimated monthly (May/2007 - Sept/2008) from 20 box of 1,0 m2 litter collector. The collected litter was fractioned into leaves, reproductive structures, branches and miscellaneous, after that they were dried and weighted. Every three months the deposited litter on the soil was sampled from 0.5 m x 0.5 m frame, dried and weighted. Also, samples soils (0-15 cm) were collected to determine the soil humidity. It was observed two predominant species Aspidosperma pyrifolium Mart. and Croton sonderianus Muell.Arg., which represent more than 50% of population Cover vegetation is defined by brush wood. The peak of leaf production occurred at the end of rainfall season expressing a strong relation between litter production and rainfall season, while the reproductive structures were defined by vegetation specie. In the first year (May/0
Similaridade e fatores determinantes na salinidade das águas superficiais do Ceará, por técnicas multivariadas Similarity and determining factors in the salinity of surface waters of Ceara by mitivariate techniques
Helba A. Q. Palácio,José R. Araújo Neto,Ana C. M. Meireles,Eunice M. Andrade
Revista Brasileira de Engenharia Agrícola e Ambiental , 2011,
Abstract: Técnicas de estatística multivariada foram empregadas com o objetivo de identificar a similaridade dos reservatórios superficiais do Ceará, com rela o à salinidade das águas e identificar os fatores determinantes da qualidade das águas. Os dados utilizados foram provenientes do banco de dados da Companhia de Gest o dos Recursos Hídricos do Ceará, no período de 1998/2009, no total de 807 amostras de 48 reservatórios. Os parametros considerados foram: Cl-, Ca2+, Mg2+, Na+, HCO3 -, CE e RAS. A análise de agrupamento hierárquico formou quatro grupos distintos, sendo determinantes os tipos e concentra es dos sais analisados. Nos grupos 1 e 2 a salinidade da água é definida principalmente pelas condi es naturais de solo e clima da regi o e nos grupos 3 e 4, além desses fatores, a influência antrópica. O emprego da análise de fator/análise de componente principal promoveu a redu o de sete características das águas superficiais do Estado Ceará, para dois componentes, sendo que o primeiro componente explicou 57,28% e o segundo, 26,77% da variancia contida nas sete variáveis. Os parametros mais representativos na variabilidade da salinidade das águas foram Cl-, CE, Na+ e Mg2+, relacionados com a solubilidade dos sais. Multivariate statistical techniques were employed in order to identify the similarity in the salinity levels of the water reservoirs of Ceará State, Brazil. Also, to identify the factors that explain the variability of water quality. The data set used in this investigation came from the Company of Water Management (COGERH). The studied period extended from 1998 to 2009, in a total of 807 samples from 48 different sources. The investigated parameters were: Cl-, Ca2+, Mg2+,Na+, HCO3 -, EC and SAR. The Hierarchical Cluster Analysis identified four groups, being the types and concentrations of the analyzed salts the determining factors. In groups 1 and 2, the salinity level of the water was, mainly, due to the geology and the climate of the region. While for group 3 and 4, besides these factors, the water salinity was influenced by human activities. According to the results, the first and the second components (independent factors) explaining, 57.28 and 26.77%, respectively, the total variance of seven variables. The most important parameters related to the variability of the water salinity level were Cl-, CE, Na+ and Mg2+, which were related to salt solubility.
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