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yields with nitrogen fertilization all point to the fact that many of the Northwest forest areas could
have future elemental deficiencies, other than nitrogen.
218. Gonzalez, J.S. and J. Richards. 1988. Early selection for wood density in young coastal Douglasfir
trees. Canadian-Journal-of-Forest-Research 18(9): 1182-1185.
Keywords: genetic tree improvement
wood quality
Abstract: Selection age for wood density in vigorous coastal Douglas-fir (Pseudotsuga
menziesii) on Vancouver Island was determined by examining the strength of the correlation
between total-stem wood density of 50-yr-old trees and the b.h. density when the trees were 5-30
yr old (b.h. age), and the efficiency in terms of gain per year of tree improvement effort by
selecting at ages 5-30, relative to selecting at age 50. The linear regression and rank correlation
between total-stem and b.h. densities improved as age increased from 5 to 15 yr, but showed no
significant improvement from 15 to 30 yr. Densities of early-growth rings fluctuated considerably
and their exclusion from the calculation of b.h. density enhanced the linear regression with totalstem
density. Efficiency estimates in terms of gain per year showed an opt. value at age 15, but
the estimates for ages 10-14 were nearly as efficient.
219. Gourley, M., M. Vomocil and M. Newton. 1990. Forest weeding reduces the effect of deerbrowsing
on Douglas fir. Forest-Ecology-and-Management 36(2-4): 177-185.
Keywords: release treatments
chemical release
tree/stand protection
growth
tree/stand health
Abstract: In January and February 1981, three-year-old bare-root Douglas fir (Pseudotsuga
menziesii) transplants were established in four clear-felled locations in the Oregon Coast Range
where browsing by black tail deer (Odocoileus hemionus columbiana) was expected. Protection
was provided against browsing by 5 physical (rigid protection tube 7.5x75 cm; protective netting,
paper budcaps; leather guard 20x5 cm; and 'Remae' budcaps) and one chemical ('Deer Away')
treatment, each of which was tested with and without complete wood control with glyphosate.
After five years, none of the protective treatments provided any growth advantages; some even
caused growth losses. In contrast, weed control, with or without additional protective measures,
consistently improved growth. By the 5th year, weeded trees averaged twice the biomass of
unweeded trees, regardless of browsing. Average tree size was largest in the treatment with no
weed competition and with no barriers to prevent browsing. Advantages of weeding were greatest
on the poorest site. Weed control, in conjunction with the large size of transplants, appeared to
prevent most loss due to damage from moderate deer-browsing.
220. Graff, J.E., Jr., R.K. Hermann and J.B. Zaerr. 1999a. Dry matter and nitrogen allocation in
western redcedar, western hemlock, and Douglas fir seedlings grown in low- and high-N soils.
Annals-of-Forest-Science 56(7): 529-538.
Keywords: nursery operations
nursery fertilization
growth
tree physiology