We measured sap flow at the branch and tree levels, and calculated tree transpiration at the stand level, in a 220-year-old Abies amabilis forest. Temporal and spatial patterns of branch sap flow rate per unit leaf area reflected differences in canopy position and diurnal variation in radiation exposure. Average leaf area normalized branch conductance of upper canopy branches ranged from 0.50 to 1.01 mm s-1.