RELATIONSHIP BETWEEN STEM DENSITY AND DRY-CANOPY EVAPORATION RATES IN CONIFEROUS FORESTS

Abstract

Our previous study summarized published data on dry-canopy evaporation in coniferous forests during the growing season and found a decrease in the Priestley–Taylor coefficient α with canopy height. We speculated that the decrease in α was caused by a decrease in stomatal conductance with tree height. However, the decrease in α may also be explained by changes in leaf area index (LAI) and/or stem density with canopy height. We found no clear relationship between LAI and α in our previous study. Here, we examined the relationship between stem density and α and found no clear relationship, indicating that the decrease in α with increasing canopy height is not explained by changes in stem density. Thus, our results support the previous speculation that decrease in α was caused by a decrease in stomatal conductance with tree height.