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Management alternatives were defined by residual stand structure and cutting cycle. The residual
stand structure was set by basal area-diameter-q-ratio (BDq) distributions, diameter-limit cuts
(assuming concurrent stand improvement), or the current diameter distribution. Cutting cycles of
10 or 20 years were applied for 200 years. The current diameter distribution was defined as the
average of the uneven-aged Douglas-fir stands sampled in the most recent Forest Inventory and
Analysis conducted in Oregon and Washington. Simulation results were compared in terms of
financial returns, timber productivity, species group diversity (hardwoods vs softwoods), size
class diversity, and stand structure. Other things being equal, there was little difference between
10- and 20-year cutting cycles. The highest financial returns were obtained with either a 58.4 cm
diameter-limit cut, or a BDq distribution with 8.4 m2 of residual basal area, a 71.1 cm maximum
diameter, and a q-ratio of 1.2. Using the current stand state as the residual distribution was the
best way to obtain high tree size diversity, and high species group diversity. Several uneven-aged
regimes gave net present values comparable to that obtained by converting the initial, unevenaged
stand to an even-aged, commercially thinned, plantation.
490. Randall, W. and G.R. Johnson. 1998. The impact of environment and nursery on survival and
early growth of Douglas-fir, noble fir, and white pine - a case study. Western-Journal-of-Applied-
Forestry 13(4): 137-143.
Keywords: nursery operations
planting operations
tree/stand protection
growth
tree/stand health
Abstract: Survival and third-year height were examined on 2383 reforestation units in
Cascade Range of western Oregon, USA, from 1983 to 1994, to determine which factors affect
reforestation success. The three species examined made up 92% of the total trees planted in the
region. Survival of Douglas fir (Pseudotsuga menziesii) varied by as much as 20% from year to
year. The most significant factor affecting reforestation success was the nursery that provided the
seedlings. Nursery affected both survival and height of Douglas fir and height for noble fir (Abies
procera) and white pine (Pinus monticola). No nursery was best for all species. Other factors that
were important for all three species were the administrative unit where the seedlings were
planted, initial plant height, aspect, and length of storage prior to planting. Other significant
factors that were important for Douglas fir were seed origin, planting month, protection, stock
type, and aspect. For noble fir, other important factors were planting month and stock type; for
white pine, the other important factor was slope. Altitude of the seed source and the planting unit
affected Douglas fir survival and height but did not affect the other two species. This supports the
smaller altitudinal bands for Douglas fir compared with noble fir and white pine.
491. Rappaport, N.G. and D.L. Wood. 1994. Pityophthorus orarius Bright (Coleoptera: Scolytidae) in
a northern California douglas-fir seed orchard: effect of clone, tree vigor, and cone crop on rate of
attack. Canadian-Entomologist 126(5): 1111-1118.
Keywords: tree/stand protection
tree/stand health
Abstract: The geographic range of Pityophthorus orarius was extended beyond the original
provenance of southern British Columbia to northern California. A survey of 457 Pseudotsuga
menziesii trees in 1985 revealed that those with heavy cone crops were more likely to be infested
by P. orarius than were those with a light crop. Furthermore, attack rates differed among clones.