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

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pruning
growth
yield
tree morphology
Abstract: Five spacing trials were established during 1957-67 at the University of British
Columbia Research Forest, covering a range of spacings from 1 to 5 m and of experimental
designs (49-tree-plot, 0.2-ha plot, rectangularity, Nelder and variable block trials). Results
showed that initial spacing is among the most important factors influencing stem and crown
development, and stand growth and yield for Douglas fir (Pseudotsuga menziesii), western
hemlock (Tsuga heterophylla) and western redcedar (Thuja plicata). Top heights were initially
taller at closer spacings, but are now similar at all spacings. Av. ht. is now shorter at close
spacing. Decreases in heights to dead and live crowns and increases in diam. of lower stem, taper
and crown size occurred as spacing increased. B.a. and stand vol. increased as spacing decreased
until onset of density-related mortality. It is concluded that initial wide spacings with
rectangularities up to 2:1 (e.g. 6x3 m) will result in efficient production of large trees of high
value and satisfactory quality. Pruning of widely spaced trees to enhance lower stem quality is
strongly recommended.
496. Reynolds, P.E., K. King, R. Whitehead and T.S. MacKay. 1986. One-year results for a coastal
British Columbia glyphosate conifer release trial. Proceedings-of-the-Western-Society-of-Weed-
Science (Vol.39): 107-117.
Keywords: release treatments
chemical release
stand conditions
growth
tree/stand health
Abstract: In trials on the W. coast of Vancouver Island in 1984, fir plantations on a
reclaimed watershed were aerially treated with 2 kg glyphosate/ha. A single spray gave good
control of Rubus spectabilis but very variable control of Alnus rubra ranging from 0 to 100%.
Gaultheria shallow [G. shallon] was not controlled by glyphosate. Control of many species was
greater on upper slopes than in the watershed valley bottom. There was minor crop tree injury to
Tsuga heterophylla and Thuja plicata with recovery after 1 year, but no injury to Picea sitchensis,
Pseudotsuga menziesii, Abies amabilis or A. grandis. Some increases in crop tree height were
noted after herbicide treatment.
497. Richmond, R.M. 1983. Problems and opportunities of forestland grazing in the Pacific Northwest.
In Forestland-grazing Ed. -.B. Roche, -Jr; Baumgartner,-DM. Pullman, USA: Washington State
University. pp. 71-73.
Keywords: release treatments
stand conditions
tree/stand health
Abstract: Grazing as a means of brush control in Douglas-fir plantations after clearcut
timber harvest was investigated in 1980-2 near Alsea, Oregon. Plots were restricted to clearcut
areas with dominant vine maple [Acer circinatum]/sword fern [Polystichum munitum]
communities. In 1980-1 a flock of 600 ewes with lambs was used and in 1982 900 dry ewes were
used. The sheep were kept as a single flock and moved from clearcut to clearcut on a scheduled