Transpiration of two willow species (Salix viminalis and Salix triandra) growing on a landfill of dredged sludge

A landfill of dredged sludge was afforested with two different willow species: Salix viminalis cv. Belgisch rood and Salix triandra cv. Noir de Vilaine. Mats of willow wickers of those two species were woven and put on the non-consolidated sludge. Next the stomatal resistance and the transpiration rate of this one year old stand was measured on five characteristic days during the vegetation period. Finally these data were extrapolated over the whole growing season to estimate the total transpiration of this stand. Two different methods to do this extrapolation were compared.