You are not currently logged in.
Access JSTOR through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Light Intensity Measurements in Rain Forest Near Santarem, Brazil
P. S. Ashton
Journal of Ecology
Vol. 46, No. 1 (Mar., 1958), pp. 65-70
Published by: British Ecological Society
Stable URL: http://www.jstor.org/stable/2256903
Page Count: 6
You can always find the topics here!Topics: Tropical rain forests, Forest canopy, Trees, Luminous intensity, Photoelectric cells, State forests, Sunlight, Rain forests, Wavelengths, Photometers
Were these topics helpful?See somethings inaccurate? Let us know!
Select the topics that are inaccurate.
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
1. A series of photometer readings were taken near Monte Alegre, Para, Brazil, on 7 August 1954. 2. These observations were made in Evergreen Rain forest at the beginning of the dry season, when there were probably fewer leaves on the trees than at any other time. 3. The readings were taken at different heights in the forest, all up one tree, from dawn to dusk during one day. 4. Despite limitations caused by the method used, the observations showed that: (a) The ground level series corresponded remarkably with those obtained by more complex methods by Evans (1939) in Nigeria. (b) The density of the second storey was the predominant controller of light intensity and duration of day when sunflecks were present within the forest canopy. (c) The shading effect of the emergent canopy is thrown over a considerable area of the neighbouring forest as the sun passes round, thus leaving few parts of the second storey unshaded, at least during one part of the day. 5. The method shows that though the worker in the tropics may have only a simple apparatus, unsuited to this type of work, the results can still be worthwhile.
Journal of Ecology © 1958 British Ecological Society