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

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nonpasteurized: 9 parts pasteurized) produced as many ectomycorrhizae as nonpasteurized field
soils and generally fewer tips than pasteurized soils. Formation of major (but not minor)
ectomycorrhizal types on all sites was influenced more by aboveground changes that accompany
clear felling and site preparation than by alterations in soil chemistry or biology.
473. Potts, S.J., B.R. Hartsough, S.E. Reutebuch and J.L. Fridley. 1997. Manual polesaw pruning of
Douglas-fir. Applied-Engineering-in-Agriculture 13(3): 399-405.
Keywords: pruning
economics
Abstract: A time-and-motion study was conducted in British Columbia of second-lift (from
2.8 to 5.6 m) pole saw pruning in a 12-year-old stand of Douglas fir (Pseudotsuga menziesii), to
help determine costs. Pruning quality was also assessed, using samples from random plots.
Productivity relationships were derived via regression analysis. Production rates using pole saws
averaged 8.2 trees per productive hour and varied according to tree and stand characteristics. Cost
per tree averaged about $2.80. Both the production rates and quality were lower than for pruning
with shears, indicating that pole saw pruning is less desirable in all aspects except one: the work
can be done from the ground instead of on a ladder.
474. Poulsen, K.M. 1996. Prolonged cold, moist pretreatment of conifer seeds at controlled moisture
content. Seed Science and Technology 24:75-87.
Keywords: nursery operations
reproduction
tree/stand health
Abstract: Cold pretreatment of imbibed seed (stratification) and seed kept at controlled
moisture contents for 3-14 weeks was tested for commercial seedlots of Abies nordmanniana,
Abies procera, Pseudotsuga menziesii and Picea sitchensis in order to give recommendations for
nursery practice. The temperature tolerance of treated seed was tested by germinating seed at four
temperature regimes. It was possible to pretreat Abies nordmanniana seed at controlled moisture
content, but the performance was not improved compared to the traditional six weeks
stratification of imbibed seed. For Abies procera seed pretreatment at controlled moisture content
for 2 + 8 weeks (2 weeks imbibed followed by 8 weeks at controlled moisture content) or more,
significantly improved the performance at the germination temperatures 15 and 30°C. For
Pseudotsuga menziesii seed pretreatment at controlled moisture content for up to 2 + 12 weeks
was superior, especially at low germination temperatures, and it was possible to redry pretreated
seed to 8% moisture content without loss of the pretreatment effect or germination capacity. For
Picea sitchensis seeds the controlled moisture content method for a duration of 7-10 weeks
proved efficient and pretreated seed of this species also tolerated redrying. It is recommended that
these improved pretreatment methods should be introduced into the nurseries.
475. Prasad, R. 2000. Some aspects of the impact and management of the exotic weed, Scotch broom
(Cytisus scoparius (L.) Link) in British Columbia, Canada. Journal-of-Sustainable-Forestry
10(3/4): 341-347.
Keywords: release treatments
manual release
growth
photosynthesis