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from the coastal source (450 m). A growth-chamber experiment confirmed the outdoor
dehardening studies. A constant temp. of + 5 degrees C with a 16-h photoperiod maintained cold
hardiness, whereas +10 and 15 degrees C with a 16-h photoperiod promoted rapid dehardening
after 20 d. The nursery environment influenced budburst; trees raised in the coastal nursery burst
bud significantly earlier than trees from the other 2 nurseries. Trees of different provenances from
the same nursery burst terminal buds only 2 d apart.
542. Scott, W., R. Meade, R. Leon, D. Hyink and R. Miller. 1998. Planting density and tree-size
relations in coast Douglas-fir. Canadian-Journal-of-Forest-Research 28(1): 74-78.
Keywords: planting operations
growth
Abstract: Test plantations were established in western Washington and Oregon to compare
tree growth at six initial planting densities ranging from 300 to 2960 trees/ha. A size-density
relation was visually apparent 3 to 4 years after planting. Inventory data collected in 1990 from
the oldest 11 trials (5 or 6 years after planting, 10 in Washington, one in Oregon) showed that
initial spacing strongly influenced early growth of coast Douglas fir (Pseudotsuga menziesii var.
menziesii). Average height and diameter at breast height were progressively larger as planting
density increased; at the widest spacing (lowest stand density), average height was 75% and
average diameter at breast height was 67% of that at the closest spacing. Trees planted at 2960
trees/ha attained breast height (1.3 m) 2 years earlier than trees planted at a density of 300/ha.
This finding has practical significance to current efforts to achieve early establishment of
plantations.
543. Sexton, J.M. and T.D. Schowalter. 1991. Physical barriers to reduce damage by Lepesoma
lecontei (Coleoptera: Curculionidae) to conelets in a Douglas-fir seed orchard in western Oregon.
Journal-of-Economic-Entomology 84(1): 212-214.
Keywords: seed orchard management
tree/stand protection
tree/stand health
Abstract: Damage to Douglas fir (Pseudotsuga menziesii) conelets in Oregon by Lepesoma
lecontei was significantly reduced by the application of a sticky barrier around the bole of the
seed orchard trees. Early conelet injury was reduced from 25% in controls to 6% in sticky barrier
treatments. No significant protection was observed in a test of a metal baffle placed around the
bole. Significant treatment effects on cone survival could not be detected. Sticky barriers are a
low-cost control that is highly pest specific and need be applied only to those trees producing a
crop in a particular year.
544. Shainsky, L.J., M. Newton and S.R. Radosevich. 1992. Effects of intra- and inter-specific
competition on root and shoot biomass of young Douglas-fir and red alder. Canadian-Journal-of-
Forest-Research 22(1): 101-110.
Keywords: planting operations
growth
tree morphology
carbon allocation
tree physiology