Influence of intercepted water on transpiration and evaporation of Salix

✍ Scribed by Stig Larsson

• Publisher: Elsevier Science
• Year: 1981
• Weight: 457 KB
• Volume: 23
• Category: Article
• ISSN: 0002-1571
• DOI: 10.1016/0002-1571(81)90118-7

✦ Synopsis

Water sprayed on leaves of Salix caprea var. viminalis and S.viminalis covered about 30% of the leaf surfaces, mostly in form of drops. Leaves from S. caprea vat. viminalis intercepted up to 210g waterm -2, as an average for both sides of the leaves, while S. viminalis intercepted 150g waterm -2. Transpiration rates were reduced by 95% during the first 15 minutes after spraying. Subsequently, transpiration rates increased and evaporation rates decreased as the water on leaves disappeared. Water sprayed on the lower side of the leaves had the greatest influence on the reduction of transpiration. Relationships between transpiration, evaporation and amount of intercepted water were found, which gives support to a formula for calculating evapotranspiration, ET, from partially wet plant surfaces

ET = 1-To + Eo

where To = transpiration from dry plant surfaces, E 0 -----evaporation from totally wet plant surfaces, C = actual intercepted amount of water, and S = interception capacity. About 50% of the intercepted water was indirectly "saved" through the reduced transpiration during the time that the leaves were wet.