Comparison of selected Douglas-fir seed sources for cambial and leader growth patterns in four western Oregon environments

The leader and cambial growth of sapling Douglas-fir (Pseudotsuga menziesii (Mirb.)Franco) from both inland and coastal varieties followed a definite pattern in fourwestern Oregon environments. Generally, buds became active first and cambial growthbecame active soon after. Leader growth stopped in August, long before cambial growth,which continued into October. Phenology, total seasonal growth, and growth patternfor trees from coastal sources from Vancouver Island, B.C., to southern Oregon weremore similar than for trees from inland sources from British Columbia to Idaho andArizona. Most of the differences among populations in one season's growth were related togrowth rate rather than growth duration.