The radiation and energy balances of coniferous and deciduous forests.

Published online
01 Jan 1973
Content type
Journal article
Journal title
Journal of Applied Ecology
DOI
10.2307/2402437

Author(s)
Tajchman, S. J.

Publication language
English
Location
USSR & Germany

Abstract

Describes a method of evaluating profile measurements above a vegetation cover in order to calculate its energy balance. The equations given by the aerodynamic method and the Bowen ratio method for calculating evapotranspiration and sensible heat fluxes from forest are shown to be applicable if the site satisfies the theoretical specifications. Data on the radiation and energy balance of a Norway Spruce forest near Munich [cf. FA 30, 77; 31, 5818] are compared with data for deciduous forests in the USSR [cf. FA 24, 3098; 25, 4582], and other forests. The levels of maximum values of temperature and specific humidity lie much higher than the zero plane displacement for wind profile (day-time), and the log-law does not fit the experimental data on temperature and humidity profiles above forest. The difference in the seasonal course of the radiation and energy balances of the two types of forests is caused mainly by albedo changes in deciduous forest. It is shown how the structure of the forest influences the vertical profiles of radiation density, transpiration and sensible heat fluxes within the canopy. The experimental data on radiation flux density within the forest canopy agree with theoretical results only when the sun's elevation is >45 deg

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