This study reports on the transpiration by a hybrid poplar (Populus trichoc
arpa x P. deltoides) plantation in East Flanders during 1997. Transpiration
was measured by sap flow techniques on individual trees and scaled to the
stand level, and was simulated by the WAVE water balance model. Relatively
high transpiration values by the poplar stand were found during the growing
season, with maximum and mean daily transpiration of 5 and 1.9 mm per day,
respectively. The seasonal (1 April-31 October) total transpiration amount
ed to 320 mm, representing roughly 70% of the potential evapotranspiration
over this period. However, this transpiration represented only about three-
fourths of the incoming precipitation. Reasonable agreement was found betwe
en measured and simulated stand transpiration. The difference between cumul
ated precipitation and cumulated actual transpiration closely mimicked the
course of the water table. Suggestions for further improvements to the WAVE
model have been made and discussed. (C) 1999 Published by Elsevier Science
B.V. All rights reserved.