A relação V/VE da radiação solar sob o dossel de uma área de Mata Atlântica

Zaia, José Eduardo; Takaki, Massanori

doi:10.1590/s0102-33061999000100005

Cited by 4 publications

(6 citation statements)

References 17 publications

(14 reference statements)

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“…4b). Such differences between clear and overcast sky conditions have been observed under crop and forest canopies (Holmes & Smith, 1977b; Zaia & Takaki, 1999; Pecot et al. , 2005).…”

Section: Discussionmentioning

confidence: 72%

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Simulation of the three‐dimensional distribution of the red:far‐red ratio within crop canopies

Chelle

Evers²,

Combes

et al. 2007

New Phytologist

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Summary• It is widely recognized that the red:far-red ratio ( ζ ) acts as a signal that triggers plant morphogenesis. New insights into photomorphogenesis have been gained through experiments in controlled environments. Extrapolation of such results to field conditions requires characterization of the ζ signal perceived by plant organs within canopies. This paper presents a modeling approach to characterize this signal.• A wheat ( Triticum aestivum ) architectural model was coupled with a threedimensional light model estimating the irradiances of virtual sensors. Architectural parameters and ζ values were measured on two contrasting spring wheat canopies under outdoor conditions. Light simulations were compared with measurements, and an analysis of sensitivity to measurement conditions was carried out.• The model results agreed well with measurements and previously published data. The sensitivity analysis showed that ζ strongly depends on canopy development as well as on sky conditions, sensor orientation, and sensor field of view.• This paper shows that modeling enables investigation of ζ distribution in a canopy over space and time. It also shows that the characterization of light quality strongly depends on measurement conditions, and that any discrepancies in results are likely attributable to different experimental set-ups. The usefulness of this modeling approach for crop photomorphogenesis studies is discussed.

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“…4b). Such differences between clear and overcast sky conditions have been observed under crop and forest canopies (Holmes & Smith, 1977b; Zaia & Takaki, 1999; Pecot et al. , 2005).…”

Section: Discussionmentioning

confidence: 72%

“…4b). Such differences between clear and overcast sky conditions have been observed under crop and forest canopies (Holmes & Smith, 1977b;Zaia & Takaki, 1999;Pecot et al, 2005). The contrasting behaviors of sideward and downward ζ* values with respect to sky type may be explained by the difference in primary light irradiances (Fig.…”

Section: Research 231mentioning

confidence: 69%

Simulation of the three‐dimensional distribution of the red:far‐red ratio within crop canopies

Chelle

Evers²,

Combes

et al. 2007

New Phytologist

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“…Theoretically, small‐sized, photoblastic seeds accumulate into a seed bank (Milberg et al . 2000) and germinate following changes in light penetration, red/far red ratio and daily temperature fluctuation caused by either gap formation (Zaia & Takaki 1999; Pearson et al . 2002) or leaf fall mediated canopy opening during the dry season (Paula & Lemos‐Filho 2001).…”

Section: Discussionmentioning

confidence: 99%

Reproductive phenology, seed germination and ex situ conservation of Pseudananas sagenarius in a semi‐deciduous tropical forest fragment

Vieira

Silveira

2010

Plant Species Biology

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Understanding the life history and ecophysiology of native species is crucial for the restoration of fragmented landscapes, such as the Atlantic Forest. In the present study, we examined the reproductive phenology and specific germination requirements of Pseudananas sagenarius (Bromeliaceae), an understory perennial herb from semi-deciduous tropical forests. The reproductive phenology was followed for 24 months and the effects of light and temperature on germination were evaluated under constant temperatures of 15, 20, 25, 30 and 35°C for both light and dark conditions. Seeds were also stored for 24 and 36 months before being allowed to germinate at optimum conditions. The reproduction of P. sagenarius was supra-annual, extended, irregular and non-synchronic, with seed dispersal occurring at the onset of the rainy season. Seeds are small, orthodox and photoblastic, and the optimum temperature for germination was 25°C, which is consistent with the soil surface temperature at dispersal. Stored seeds showed a minor decrease in germinability, but maintained their viability after 36 months. Recruitment from seed is likely to occur at the onset of the rainy season or after gap formation. Our results suggest that P. sagenarius has the potential to form seedling banks and that seeds retain their germinative potential after storage.

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“…A maior luz incidente sobre a copa de Gymnanthes concolor na trilha clara, aparentemente, não favoreceu a atividade reprodutiva quando comparada com a trilha escura. Valores superiores de luz na borda (Zaia & Takaki 1999, Hernandes et al 2004) favorecem a maior produtividade de flores e frutos em árvores nessas condições (F.F.D. Neves & L.P.C.…”

Section: Discussionunclassified

“…Contudo, a maioria dos trabalhos sobre a luz em florestas trata da descrição de hábitats (e.g. Bazzaz & Pickett 1980 e referências neste, Chazdon & Fetcher 1984, Zaia & Takaki 1999, não testando sua influência no processo reprodutivo de plantas ou animais (Saunders et al 1991, Murcia 1995. Conseqüentemente, a resposta fenológica das plantas na natureza decorrente da variação luminosa é pouco conhecida (Ghazoul & McLeish 2001) (Johns 1988).…”

Section: Introductionunclassified

Influência da abertura de trilhas antrópicas e clareiras naturais na fenologia reprodutiva de Gymnanthes concolor (Spreng.) Müll. Arg. (Euphorbiaceae)

Alberti

Morellato

2008

Rev. bras. Bot.

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Influência da abertura de trilhas antrópicas e clareiras naturais na fenologia reprodutiva deand phenological variables did not differ significantly between trees in lighter trail and darker trail. Therefore, the light incidence on lighter trail did not promote a significantly phenological change. The result is supported by the low number of significant regressions between light incidence and phenological variables. Trees adjacent to gaps presented a light incidence variation significantly higher than those trees far away from gaps, but did not differ in respect to interannual variation in phenological variables. Hence, the higher light incidence after the creation of gaps did not affect significantly the phenology of G. concolor as well, which may need even higher amounts of light to respond to gaps or open trails. Our results may give some insight to the design of ecological trails or other open spaces on natural reserves, to reduce its impact on flowering and fruiting production of the species nearby.

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A relação V/VE da radiação solar sob o dossel de uma área de Mata Atlântica

Cited by 4 publications

References 17 publications

Simulation of the three‐dimensional distribution of the red:far‐red ratio within crop canopies

Simulation of the three‐dimensional distribution of the red:far‐red ratio within crop canopies

Reproductive phenology, seed germination and ex situ conservation of Pseudananas sagenarius in a semi‐deciduous tropical forest fragment

Influência da abertura de trilhas antrópicas e clareiras naturais na fenologia reprodutiva de Gymnanthes concolor (Spreng.) Müll. Arg. (Euphorbiaceae)

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