High Altitude Plant Physiology Research Centre, Garhwal University, Srinagar-246174, U.P., India
Leaf temperature, water vapour transfer conductances and transpiration rate were studied in 44 trees and 6 shrub species under their natural environments in Garhwal Himalaya. The results revealed that while boundary layer conductance for water vapour increased with increasing altitude the stomatal conductance, diffusion conductance and leaf temperature decreased. Boundary layer conductance was found significantly higher than the stomatal and diffusion conductance. The rate of transpiration decreased with increasing altitude and is found to be strongly influenced by the stomatal conductance. The leaves of tree species exhibited higher rate of transpiration than those of shrub species. The eco-physiological significance of the results is discussed.
