An investigation of Douglas-fir leave-tree mortality in the sub-boreal spruce zone: A temporal assessment of water relations under pre and postharvest conditions.

Assessing the climatic sensitivity of Douglas-fir at its northern range margins in British Columbia, Canada

“…Douglas-fir growth responses over recent decades indicate that precipitation will continue to be a limiting factor across this area and may become more critical in the future with warming temperatures. Management of this species at its northern distributions will require thoughtful consideration of the link between genecology, growth, and soil moisture and how these parameters may change over time (Rogers 2006). Although too early to predict the future state of Douglas-fir at its NRM, our results suggest that it may become particularly sensitive to climate in this portion of its range.…”

“…These unique distribution patterns may partly reflect the influence of short-term extreme climatic events such as frost events or ice storms that limit establishment and juvenile development (Jull 1999;DeLong 1999). Douglas-fir productivity at its northern extremes can exceed that of other co-occurring conifers, creating considerable management interest for this species at its NRM (Jull 1999;Kessler 1999;Rogers 2006). NRM Douglas-fir abundance may be in decline, possibly associated with Douglas-fir bark beetle (Dendroctonus pseudotsugae) outbreaks, historical fire suppression, or post-harvest conversion to other species (Daintith and Vyse 1999;Jull 1999).…”