I studied how microclimate variables influence the growth of white spruce trees (Picea glauca (Moench) Voss) in pure and mixedwood stands in north-eastern British Columbia. My key finding is that stand composition and structure are essential determinants of how spruce radial growth and sap flow respond to fluctuations in climate variables. A combination of warmer temperatures and drought during summer will negatively affect white spruce trees growth in pure and mixedwood stands in the studied region. Spruce sap flow in both stand types is likely to increase as the climate warms, increasing the demand for soil water. White spruce growing in mixedwood stands might be more sensitive to drought stress than in pure stands due to the higher competition for limiting resources (primarily water). I provide information that will be useful in modeling and managing these stands across western Canada under current and future climate conditions.
