Comparison of UVA Absorbance in Sun and Shade Leaves
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چکیده
I n t r o d u c t i o n M e t h o d s
منابع مشابه
Responses of photosystem I compared with photosystem II to high-light stress in tropical shade and sun leaves
Sun and shade leaves of several plant species from a neotropical forest were exposed to excessive light to evaluate the responses of photosystem I in comparison to those of photosystem II. Potential photosystem I activity was determined by means of the maximum P700 absorbance change around 810 nm ( A810max) in saturating far-red light. Leaf absorbance changes in dependence of increasing far-red...
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Background/Purpose: This paper has considered the erythemal UV (UVery), UVA and visible irradiances in the shade of Australian trees for each season at a sub-tropical southern hemisphere site. Methods: The irradiances in tree shade have been measured with radiometers as a percentage of the irradiances in the sun for each season of the year. Results: Although the solar irradiances are lower in w...
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Specific leaf area ( the ratio of leaf area to dry mass) is one of the most important ecological variables can be viewed as the tradeoff between ecosystem mass balance and ecosystem energy balance. This variable is further particularly sensitive to changes in the external environment and in the internal functioning of the plant. In this research, we studied the effect of species and leaf posi...
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The solar spectral UVR irradiances in tree shade and sunlight have been measured in a sub-tropical southern hemisphere summer. The spectral data allowed the UVB and UVA irradiances and the biologically effective irradiances to be calculated for different harmful biological processes to human skin and eyes. The average of the ratio of the UVA to UVB irradiances was lower by 26% in the shade comp...
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This paper has provided the first set of quantitative data of diffuse erythemal UV and UVA in tree shade at a sub-tropical Southern Hemisphere latitude. Over the summer, approximately 60% of the erythemal UV radiation in the tree shade is due to the diffuse component. Similarly, approximately 56% of the UVA radiation in the tree shade is due to the diffuse component. In the tree shade these dif...
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