Direct measurement of evaporation of intercepted water from forest canopies.

Published online
15 Apr 1994
Content type
Journal article
Journal title
Journal of Applied Ecology

Teklehaimanot, Z. & Jarvis, P. G.

Publication language


Spacing treatments were created in stands of Sitka spruce (Picea sitchensis) near Edinburgh, Scotland, 3 yr after establishment, by thinning out the existing 2-m spacing to give plots with 8-, 6-, and 4-m spacings. Trees similar in size and form to the trees in each plot were cut from a neighbouring plantation and suspended from a load cell in locations within the treatment plots where trees were missing as a result of wind-blow. These cut trees were sprayed with simulated rain and weighed during evaporation of the intercepted water. Boundary layer conductance per tree increased with spacing from 0.82 m3/s in the 2-m plot to 5.92 m3/s in the 8-m plot, whereas boundary layer conductance per unit ground area decreased from 0.24 m/s to 0.09 m/s as the density of trees decreased. Canopy storage capacity was a property of individual trees and unaffected by tree density. Assumptions in the Rutter model of interception loss that evaporation from the wet canopy is adequately given by the Penman equation are verified.

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