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XIX.—Photochemical Measurements of Light Intensity in Two Common Vegetation Types in Tropical Africa, by Means of the Improved Eder-Hecht Photometer

Published online by Cambridge University Press:  15 September 2014

John Phillips ,
J. D. Scott  and
J. Y. Moggridge
J. Y. Moggridge
Affiliation:
Dept. Tsetse-fly Research, Kondoa-Irangi, Tanganyika Territory
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Summary

(1) A year's measurement of the light-intensity in an exposed site (“mbuga”) and in a Berlinia woodland community, Kikori (4° 21' S.), Tanganyika, by means of the Eder-Hecht Graukeilphotometer is described.

(2) The Bunsen-Roscoe units per second are shown to be very high, even under canopy of the Berlinia; they are very much greater than measurements recorded by Dorno for Assuan and Rio de Janeiro.

(3) While there is a positive correlation between the B.-R. values and the hours of direct sunshine, it is also clear that during cloudy periods (less than 50 per cent, of possible sunshine is experienced at Kikori and on the Central Plateau of East Africa generally) the B.-R. values are also very high.

(4) There is a positive correlation between the values of the Eder-Hecht photometer (in terms of blue-violet-ultraviolet rays), and the readings of the Livingston radio-atmometer measuring the total light-intensity of the same stations in terms of cubic centimetres of water.

(5) In virtue of the peculiar effects of the light of Tropical Africa upon the European nervous system, it is urged that quantitative and qualitative studies of the light in those regions should be investigated.

(6) Field biologists should make greater use of this efficient, cheap, simple, and portable instrument.

Type
Proceedings
Information
Proceedings of the Royal Society of Edinburgh , Volume 51 , 1932 , pp. 150 - 161
Copyright
Copyright © Royal Society of Edinburgh 1932

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References

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