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Search Results: 1 - 10 of 229159 matches for " Cláudio José Reis de; "
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Respostas de plantas de Schizolobium amazonicum [S. parahyba var. amazonicum] e Schizolobium parahyba [Schizolobium parahybum] à deficiência hídrica
Carvalho, Cláudio José Reis de;
Revista árvore , 2005, DOI: 10.1590/S0100-67622005000600009
Abstract: juvenile plants of s. amazonicum (paricá) and s. parahyba (guapuruvu) were subjected to two cycles of water stress in greenhouse conditions. the water deficit induced the increase in total soluble amino acids, proline, total soluble sugars and k+ contents in the leaf tissues, lowering osmotic potential values in both species. however, the analysis of the pressure-volume curve results suggests that the species respond differently to water stress, and that s. amazonicum presents greater capacity of osmotic adaptation than s. parahyba.
Intera??es biofísicas em espécies arbóreas potencialmente acumuladoras de fósforo: diversidade de irradiancia e de comportamento hídrico
Oliveira, Patricia Chaves de;Carvalho, Cláudio José Reis de;
Acta Amazonica , 2008, DOI: 10.1590/S0044-59672008000300008
Abstract: the agreement of biophysic interaction between phosphorus accumulative species, such as neea macrophylla and cecropia palmata with radiation and water available in secondary forests in the northeast of pará, becomes essential for the composition of agroforest systems and enriched forests. the objective of this research was to identify how much radiation (par, bar and phyar) crossed over to the canopies of the species studied, taking into consideration the tree aggregation density and distance from the soil, as well as the water behavior by determining the water potential (predawn and midday) in different climatic periods. the results showed that cecropia palmata had the highest irradiances, independent of tree aggregation, suggesting better conditions for photosynthetic and morphogenic processes of the species that comes under the influence of its canopies. in respect to water behavior, a clear stratification between three species was observed, where cecropia palmata was the species that developed the highest water potential midday, signaling fantastic tolerance to dry periods and consequently maintaining a more stable turgidity condition, which is essential to the photosynthetic process, while casearia arborea can be considered the more sensitive, for it reached a very negative water potencial (y). the effect of the climatic period on the water potential determined their reduction for all species in the months with less pluviometric precipitation
Respostas de pupunheiras (Bactris gasipaes Kunth) jovens ao alagamento
Carvalho, Cláudio José Reis de;Ishida, Fran?oise Yoko;
Pesquisa Agropecuária Brasileira , 2002, DOI: 10.1590/S0100-204X2002000900005
Abstract: the objective of this work was to study the effects of waterlogged soil on the stomatal conductance, the relative water content, the chlorophyll content and on the n, p, k and soluble sugar concentrations of leaf, bulb and root tissues of young pijuayo palms (bactris gasipaes kunth). six month old age plants were submitted to flooding by continuous periods of seven, 14 and 21 days. flooding induced the closure of the stomata, although the leaf tissues have maintained high relative water contents (about 90%). root anoxia also induced reduction of the contents of total chlorophyll, organic n, p and mainly k in leaf tissues and significant reduction of the root biomass. in the flooded plants, the soluble sugar contents of the leaves, bulb and roots were higher than in the same tissues of the control plants. although no death of plants have been detected to the end of the experimental period, these metabolic alterations allow to affirm that this species (bactris gasipaes kunth) is sensitive to the root flooding.
Respostas de pupunheiras (Bactris gasipaes Kunth) jovens ao alagamento
Carvalho Cláudio José Reis de,Ishida Fran?oise Yoko
Pesquisa Agropecuária Brasileira , 2002,
Abstract: O objetivo deste trabalho foi estudar os efeitos do encharcamento do solo sobre a condutancia estomática, o conteúdo relativo de água, o teor de clorofila e a concentra o de N, P, K e de a úcares solúveis nos tecidos das folhas, bulbos e raízes de pupunheiras (Bactris gasipaes Kunth) jovens. Plantas com seis meses de idade foram submetidas ao alagamento das raízes por períodos contínuos de sete, 14 e 21 dias. O alagamento induziu o fechamento dos est matos, apesar de os tecidos das folhas terem mantido conteúdos relativos de água em torno de 90%. O alagamento provocou a redu o dos teores de clorofila total, N organico, P e principalmente K nos tecidos foliares e redu o significativa da biomassa das raízes. A anoxia do sistema radicular induziu o acúmulo de a úcares solúveis nos tecidos de folhas e, principalmente, de bulbos e raízes. Apesar de n o ter sido detectada morte de nenhuma planta até o final do período experimental, este conjunto de altera es metabólicas permite afirmar que a pupunheira é sensível ao alagamento das raízes.
Remo o de cálcio de efluente de máquina de papel por precipita o/coprecipita o
José Carlos Leandro de Sousa,César Reis,Efraim L. Reis,Cláudio M. Silva
Tecno-Lógica , 2011,
Abstract: Nas fábricas integradas de celulose e papel, o efluente gerado pela máquina de papel pode ser considerado um efluente setorial,denominado de água branca, devido à concentra o elevada de cálcio. Neste trabalho foram realizados experimentos com objetivos decompreender o comportamento do efluente em fun o do pH e desenvolver metodologias de remo o de cálcio da água branca, demodo a proporcionar o reuso da água e a recupera o de cálcio. Titula es potenciométricas foram realizadas com HCl 0,022 mol L-1 ecom NaOH 0,025 mol L-1padronizados, após ajuste de pH do efluente em 12,0 e 2,0 respectivamente, às quais indicaram pontos deinflex o referentes à carbonato, bicarbonato e caulim, componentes com capacidade de intera o com o cálcio solúvel. Os métodos deremo o de cálcio consistiram de coprecipita o/adsor o com hidróxidos de ferro (III) e de alumínio e precipita o na presen a deoxalato de sódio. Os resultados apontaram que em baixas concentra es de sulfato férrico e sulfato de alumínio, a coprecipita o decálcio é baixa. Nos ensaios de adsor o na presen a de Fe(OH)3 e Al(OH)3, notou-se que o aumento da concentra o de sulfato férricopossibilitou um ligeiro aumento da remo o de cálcio (16,5 a 31,0%), chegando a 65,0% na soma dos processos deadsor o/precipita o em pH 10,0. No caso do sulfato de alumínio as porcentagens de remo o foram indiferentes (~ 10,0%). Emrela o à precipita o de Ca2+ na presen a de oxalato, observou-se remo o de porcentagens satisfatórias na forma de oxalato decálcio (75% a 87%), mantendo-se o efluente com condutividade e pH praticamente inalterados, o que é muito desejável, já que oaumento da condutividade do efluente tratado na reutiliza o provoca efeito de quebra das folhas de papel. O oxalato de cálciorecuperado pode ser calcinado, sendo convertido a carbonato de cálcio, para posterior reuso. Testes em escala piloto devem serrealizados com o objetivo de validar o reuso da água e do cálcio provenientes da máquina de papel. In integrates pulp and paper mills, the effluent generated by the paper machine can be considered as a sector effluent, called white water, due to the high concentration of calcium. In this work, experiments were conducted to understand the behavior of the effluent in different pH values and to develop removal methods of calcium from the white water, aiming the reuse of water and the calcium recovery. Potentiometric titrations were carried out with HCl 0.022 mol L-1 and NaOH 0.025 mol L-1 standards, after adjusting the effluent pH at 12.0 and 2.0; respectively, which indicated inflection points for t
Arvores prestadoras de servi?os ecológicos na Amaz?nia Brasileira
Chaves de Oliveira,Patrícia; Reis de Carvalho,Cláudio José; Abreu Sá,Tatiana;
Universitas Scientiarum , 2010,
Abstract: the metabolism of rhizospheres of plants that accumulate phosphorus (p) as neea macrophylla and cecropia palmata can exert certain influence on soil dynamics as a tolerance against environmental stresses, mostly in relation to phosphorus (p), aluminum (al) and organic matter (mo) concentrations. the objective of this work was to characterize the profiles of the rhizospheres of selected species and to determine wood, leaf and total biomass as an alternative to the increment of the carbon produced. materials and methods. we selected individual trees in two secondary forests (capoeiras), one enriched and another one only with natural vegetation in the igarapé-a?ú city, state of pará, for measuring the concentrations of phosphorus (p), aluminium (al) and organic matter (mo). results. soil adjacent to the rhizosphere of neea showed higher concentrations of phosphorus and organic matter than cecropia, however low concentrations of aluminium had been observed in soil under the influence of cecropia. conclusions. trends of a reduction on phosphorus and organic matter concentrations in a potential scale with the increase of aluminium concentrations had been observed in all the rhizospheres. leaf biomass did not differ between species, while wood biomass did differ between species.
Rizosferas de árvores acumuladoras de fósforo na Amazonia Brasileira
Chaves de Oliveira,Patrícia; Reis de Carvalho,Cláudio José;
Universitas Scientiarum , 2011,
Abstract: objective. with the purpose of knowing the strategies of tolerance of two phosphorus-accumulating species (neea macrophylla and cecropia palmate) and a non-accumulating species (casearia arborea) to phosphorus-deficient soils, we characterized the rhizosphere of these species using a multivariate analysis and correlation matrices in relation to the concentrations of organic phosphorus, available phosphorus, soil organic carbon, organic carbon from microbial biomass, acid phosphatase enzyme activity, and root infection by mycorrhizal fungi. materials and methods. the research was carried out in the igarapé-a?ú town, state of pará, brazil in secondary forests with five years of regeneration, where the parameters above mentioned were monitored. results. results did not reveal significant differences between the species depending on the characteristics of the soil next to the rhizospheres, suggesting homogeneous conditions. the enzymatic activity was slightly higher in the species with less potential in accumulating p (casearia arborea) suggesting that efficiency in p use is not determined by the enzymatic activity. conclusions. neea macrophylla presented a slightly higher number of mycorrhizal root infections in comparison to the other species, indicating that this could be a tolerance strategy in those environments, while in cecropia palmata and casearia arborea it seems that enzymatic activity is the strategy employed.
Arvores prestadoras de servi os ecológicos na Amaz nia Brasileira
Patrícia Chaves de Oliveira,Cláudio José Reis de Carvalho
Universitas Scientiarum , 2010,
Abstract: Trees of ecological services in the Brazilian Amazon. The metabolism of rhizospheres of plants that accumulate phosphorus (P) as Neeamacrophylla and Cecropia palmata can exert certain influence on soil dynamics as a tolerance against environmental stresses, mostly inrelation to phosphorus (P), aluminum (Al) and organic matter (MO) concentrations. The objective of this work was to characterize theprofiles of the rhizospheres of selected species and to determine wood, leaf and total biomass as an alternative to the increment of the carbonproduced. Materials and methods. We selected individual trees in two secondary forests (capoeiras), one enriched and another one onlywith natural vegetation in the Igarapé-A ú City, state of Pará, for measuring the concentrations of phosphorus (P), aluminium (Al) andorganic matter (MO). Results. Soil adjacent to the rhizosphere of Neea showed higher concentrations of phosphorus and organic matterthan Cecropia, however low concentrations of aluminium had been observed in soil under the influence of Cecropia. Conclusions. Trendsof a reduction on phosphorus and organic matter concentrations in a potential scale with the increase of aluminium concentrations had beenobserved in all the rhizospheres. Leaf biomass did not differ between species, while wood biomass did differ between species.
Rizosferas de árvores acumuladoras de fósforo na Amazonia Brasileira
Patrícia Chaves de Oliveira,Cláudio José Reis de Carvalho
Universitas Scientiarum , 2011,
Abstract: Rhizosphere of tress that accumulate phosphorus in the Brazilian Amazon. Objective. With the purpose of knowing the strategiesof tolerance of two phosphorus-accumulating species (Neea macrophylla and Cecropia palmate) and a non-accumulating species(Casearia arborea) to phosphorus-deficient soils, we characterized the rhizosphere of these species using a multivariate analysis andcorrelation matrices in relation to the concentrations of organic phosphorus, available phosphorus, soil organic carbon, organic carbonfrom microbial biomass, acid phosphatase enzyme activity, and root infection by mycorrhizal fungi. Materials and methods. Theresearch was carried out in the Igarapé-A ú town, state of Pará, Brazil in secondary forests with five years of regeneration, where theparameters above mentioned were monitored. Results. Results did not reveal significant differences between the species depending onthe characteristics of the soil next to the rhizospheres, suggesting homogeneous conditions. The enzymatic activity was slightly higherin the species with less potential in accumulating P (Casearia arborea) suggesting that efficiency in P use is not determined by theenzymatic activity. Conclusions. Neea macrophylla presented a slightly higher number of mycorrhizal root infections in comparisonto the other species, indicating that this could be a tolerance strategy in those environments, while in Cecropia palmata and Caseariaarborea it seems that enzymatic activity is the strategy employed.
Earthworms, ants and other arthropods as soil health indicators in traditional and no-fire agro-ecosystems from Eastern Brazilian Amazonia
ROUSSEAU, Guillaume Xavier;SILVA, Paulo Rogério dos Santos;CARVALHO, Cláudio José Reis de;
Acta zoológica mexicana , 2010,
Abstract: deforestation of the amazonian rainforest and conversion to agriculture with the use of fire creates a mosaic of occupied lands and secondary forests. considering the fundamental role of soil macrofauna and the lack of information about its resilience to deforestation, this study characterized the earthworms, ants and other soil arthropod communities in secondary forests of 40 and 20 years of age and in cropping system and pastures prepared with slash-and-burn or chop-and-mulch in the brazilian eastern amazonia. soil macrofauna was sampled according to the tsbf (tropical soil biological and fertility) methodology. four sub-indices and one "macrofauna soil health index" were calculated using five principal component analyses. the macrofauna index identified better soil health in chop-and-mulch crops, followed by the 40 yr-old forest and the chop-and-mulch pasture. these results confirmed the fundamental role of old secondary forests for soil biodiversity conservation and the potential of the chop-and-mulch technique to mitigate the effects of land use changes.
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