Consulta: creatorFacets:"Souza,Gustavo M."
Registros recuperados: 8
Data/hora: 13/06/2024 00:45:56

Photosynthetic responses of four tropical tree species grown under gap and understorey conditions in a semi-deciduous forest
Provedor de dados: 88
Autores: Souza,Gustavo M.; Sato,Agnaldo M.; Ribeiro,Rafael V.; Prado,Carlos Henrique B. A.
Leaf CO2 assimilation (A) as a function of photosynthetic photon flux density (Q) or intercellular CO2 concentration (Ci) and chlorophyll fluorescence measurements were carried out on four tropical woody species growing in forest gap and understorey (Bauhinia forficata Link. and Guazuma ulmifolia Lam. as pioneers, and Hymenaea courbaril L. and Esenbeckia leiocarpa Engl. as non-pioneers). Chlorophyll fluorescence indicated similar acclimation capacities of photochemical apparatus to contrasting light environments irrespective to plant species. Maximum CO2 assimilation and quantum yield derived from A/Q curves indicated higher photosynthetic capacity in pioneer than in non-pioneer species in forest gap. However, the differences among species did not show a...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Acclimation; Chlorophyll fluorescence; Forest succession; Leaf gas exchange; Photosynthetic response curves.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042010000400002

Sistemas complexos: novas formas de ver a Botânica
Provedor de dados: 88
Autores: Souza,Gustavo M.; Buckeridge,Marcos S.
Uma parte da ciência denominada Complexidade vem se desenvolvendo rapidamente durante os últimos 15 anos e as aplicações de tais ferramentas às Ciências Vegetais são iminentes. Na presente revisão, são apresentados conceitos básicos relacionados à Complexidade e dados alguns exemplos de suas aplicações em diferentes áreas da Botânica. O argumento principal deste trabalho é que a melhor compreensão e conseqüente aplicação de tais enfoques à taxonomia, fisiologia, anatomia e ecologia pelos botânicos provavelmente levará a uma ampliação considerável do que se sabe sobre os vegetais.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Atrator; Botânica; Complexidade; Fractais; Redes neurais.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042004000300002

Approximate Entropy as a measure of complexity in sap flow temporal dynamics of two tropical tree species under water deficit
Provedor de dados: 42
Autores: Souza,Gustavo M.; Ribeiro,Rafael V.; Santos,Mauro G.; Ribeiro,Henrique L.; Oliveira,Ricardo F.
Approximate Entropy (ApEn), a model-independent statistics to quantify serial irregularities, was used to evaluate changes in sap flow temporal dynamics of two tropical species of trees subjected to water deficit. Water deficit induced a decrease in sap flow of G. ulmifolia, whereas C. legalis held stable their sap flow levels. Slight increases in time series complexity were observed in both species under drought condition. This study showed that ApEn could be used as a helpful tool to assess slight changes in temporal dynamics of physiological data, and to uncover some patterns of plant physiological responses to environmental stimuli.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Approximate Entropy; Complexity; Sap flow; Time series analysis; Tropical ecophysiology; Water deficit.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652004000300015

Proline content and protein patterns in Eucalyptus grandis shoots submitted to high and low temperature shocks
Provedor de dados: 52
Autores: Souza,Gustavo M.; Cardoso,Victor J. M.; Gonçalves,Antonio N.
Proline content and protein patterns changes in response to temperature shocks of both acclimated and non acclimated E. grandis shoots cultivated in vitro were investigated. Analysis of soluble proteins through SDS-PAGE and proline were carried out after 12h at 12ºC (cold acclimation) or 33ºC (heat acclimation), and immediately after temperature shocks at 41ºC and 0ºC. Analyses were also performed 24h after the temperature shocks (recovery period). Temperature treatment at 0ºC did not change soluble protein patterns both in acclimatized and non acclimatized plants, whereas cold temperature induced high proline levels, which kept relatively high after recovery period. Three novel, probably HSPs, proteins (90.5, 75 and 39 kDa) were observed in both...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Heat shock protein; Proline; Recovery; Stress; Temperature shock.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132004000300004

Changes in network connectance and temporal dynamics of gas exchange in Citrus sinensis under different evaporative demands
Provedor de dados: 61
Autores: Souza,Gustavo M.; Ribeiro,Rafael V.; Pincus,Steven M.
Stomatal aperture is an essential factor both in regulation of transpiration and net photosynthesis. This regulation is especially important in the response of plants to drought or to an increase in leaf-to-air vapor pressure difference (VPD); however, such a regulation is part of a complex dynamical environment, associated with multiple regulatory pathways. Accordingly, we studied the effects of VPD on gas exchange of Citrus sinensis via the evaluation of two complementary analytic approaches, to approach an understanding of the full scope of the system interactions. First, we used classical statistical methodologies, e.g., means, coefficient of variation, and linear correlation. Second, we used measures developed for more model-independent applications,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Approximate entropy; Leaf-to-air vapor pressure difference; Network modulation; Time-series analysis.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000300001

Water deficit affects photosynthetic induction in Bauhinia forficata Link (Fabaceae) and Esenbeckia leiocarpa Engl. (Rutaceae) growing in understorey and gap conditions
Provedor de dados: 61
Autores: Portes,Maria T.; Alves,Thiago H.; Souza,Gustavo M.
In tropical forests, light is considered the most limiting resource for plant growth and reproduction. Besides light, water deficit leads invariably to a decrease in photosynthesis. Thus, despite of the unquestionable role of light in CO2 assimilation (A), it is expected that water deficit affects and limits the light utilization by plants. In this study, we investigated how water deficit influenced the photosynthetic induction of the early successional tree Bauhinia forficata (Fabaceae) and the late successional Esenbeckia leiocarpa (Rutaceae) in the understorey and in the forest gap. Field measurements were carried out in June and August 2006 in plants of approximately two-years-old. In August, the plants were subjected to a period of 45 d without rain...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Drought; Ecophysiology; Gas exchange; Light utilization; Sunflecks; Tropical forest succession.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000400007

The complexity-stability hypothesis in plant gas exchange under water deficit
Provedor de dados: 61
Autores: Souza,Gustavo M.; Pincus,Steven M; Monteiro,José Alberto F.
We hypothesized that more complex, i.e. irregular, temporal dynamics and a more interconnected overall network supports greater stability to gas exchange parameters (herein, CO2 net assimilation and transpiration) in plants under water deficit. To test this hypothesis two genotypes of Phaseolus vulgaris were subjected to a period of absence of irrigation, and subsequent rewatering to achieve recovery. Gas exchanges parameters were measured each 10 s during 6 h to obtain time series to evaluate complexity by Approximate Entropy (ApEn) calculations, and network connectance in each water regime. Notably, the Jalo Precoce genotype showed significantly more stability than the Guarumbé genotype under system perturbation, coincident with greater irregularity in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Approximate Entropy; Complexity; Network connectance; Plant stress theory; Photosynthesis; Temporal dynamics; Water deficit.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000400004

Autonomy and network modulation of photosynthesis and water relations of Coffea arabica in the field
Provedor de dados: 61
Autores: Camargo-Bortolin,Lívia H.G. de; Prado,Carlos H.B. A.; Souza,Gustavo M.; Novaes,Paula.
The degree of connection between leaf gas exchange and leaf water potential, and the autonomy of these variables in relation to meteorological conditions were determined in three cultivars of Coffea arabica during clear and cloudy days. High values of vapor pressure deficit, air temperature and photosynthetic photon flux density resulted in low leaf autonomy during a clear day, irrespective the degree of connection among leaf physiological variables. Tight synchronization between physiological and meteorological variables was considered one important cause of net photosynthesis (P N) decreasing during a clear day. In contrast, diurnal P N was around three times higher on a cloudy day, when all cultivars presented high autonomy. Principal component analyses...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffea canephora; Connectance degree; Daily net photosynthesis; System analysis; Water stress.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000200006