IntensIve sIlvIculture - Forest Science Labs - Research Network ...

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tree physiology
Abstract: Douglas fir seedlings (2+0), unfertilized or fertilized with ammonium nitrate in
Oct. 1983, were planted out in Feb. 1984 near Corvallis, Oregon. Rye grass was grown on half
the plots to induce water stress during the typical summer drought. Sucrose was applied to soil
around each seedling to stimulate microbial growth and thus to immobilize nitrogen in the
microbial biomass and create nitrogen stress in Douglas fir. Fertilized seedlings had earlier
budbreak, produced more shoot growth and had higher relative growth rates, net assimilation
rates and leaf area ratios than unfertilized seedlings. Grass significantly increased predawn
moisture stress in both fertilized and unfertilized seedlings by early Aug. By 3 Sep., unfertilized
seedlings growing with grass were significantly more stressed than other seedlings. Fertilizer did
not have a significant effect on concn. of free amino acids and total N at the end of the growing
season, but grass competition affected both N and carbohydrate chemistry.
366. Marshall, D.D. and R.O. Curtis. 2002. Levels-of-growing-stock cooperative study in Douglas-fir:
report no. 15 - Hoskins: 1963-1998. Pacific-Northwest-Research-Station,-USDA-Forest-Service
Research-Paper PNW-RP-537. 80 p.
Keywords: thinning
commercial thinning
growth
yield
tree/stand health
tree morphology
Abstract: The cooperative levels-of-growing-stock (LOGS) study in Douglas-fir
(Pseudotsuga menziesii (Mirb.) Franco) was begun to study the relations between growing stock,
growth, cumulative wood production, and tree size in repeatedly thinned stands. This report
summarizes results from the Hoskins installation through age 55. Growing stock has been
allowed to accumulate for 19 years since the last treatment thinning was applied in this high site
class II natural stand. Volume and diameter growth were strongly related to growing stock. Basal
area growth-growing stock relations were considerably weaker. Differences in tree size and
volume distribution were considerable. Culmination of mean annual increment has not occurred
for any of the treatments, although the control has culminated for total stem cubic volume and is
near culmination for merchantable cubic volume. Only small differences are seen in growth
percentages between thinning treatments. Results demonstrate potential flexibility in managing
Douglas-fir to reach a range of objectives.
367. Marshall, P.L. 1988. A decision analytical approach to silvicultural investment decisions. Forest-
Economics-and-Policy-Analysis-Research-Unit,-University-of-British-Columbia Working-Paper
110. 28 p.
Keywords: planting operations
thinning
precommercial thinning
economics
growth
Abstract: A brief review of the literature is presented on methods for achieving optimal
silvicultural decisions. The methods are generally computationally cumbersome and difficult to
convert to simpler approximations required for most silvicultural decisions. An alternative