Compression wood has little impact on the water relations of Douglas-fir (Pseudotsuga menziesii) seedlings despite a large effect on shoot hydraulic properties.

• Compression wood has been shown to reduce stem permeability, but it is not known to what extent it affects leaf-level processes. Here, we report whole-plant hydraulic properties of Douglas-fir (Pseudotsuga menziesii) seedlings induced to form varying amounts of compression wood. • Seedlings were grown under three bending treatments to assess the impact of compression wood on hydraulic properties, including stomatal conductance (gs ), above-ground shoot conductance (Kl(abg) ), and both specific and leaf area-specific conductivity (ks and kl , respectively). • Kl(abg) was significantly lower (50% reduction) in severely bent seedlings than in controls. Similarly, both ks and kl of the main axis were significantly reduced (by 52% and 46%, respectively) in severely bent seedlings relative to controls. Seedlings in the moderate bending treatments had ks and kl that were intermediate between controls and severe bending. • Despite clear differences in above-ground shoot hydraulic properties, severely bent seedlings maintained the same water potentials as controls and had similar diurnal patterns of gs . This suggests that when the entire soil-plant-atmosphere continuum is considered, even a severe reduction in stem ks caused by compression wood has little impact on leaf-level processes.