Effect of Wind on the Transpiration of Young Trees

The effects of wind on the transpiration rates of four plant species, Pinus sylvestris L., Quercus robur L., Fagus sylvatica L. and Sorbus aucuparia L., were studied in a controlled environment wind tunnel. Transpiration declined with increasing wind speed in a manner consistent with predictions of the Penman-Monteith equation. The stomatal resistance declined with increasing wind speed in two species and increased in one, but this effect was smaller than reported in other studies. In all cases the magnitude of the stomatal response was over-shadowed by the declining leaf to air vapour pressure difference.