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

152
responses in terms of increased risk of frost damage are unclear, since projected changes are
small (i.e., a few days).
343. Lindsey, G.D. and J. Evans. 1983. Evaluation of zinc phosphide for control of pocket gophers on
Christmas tree plantations. Tree-Planters' Notes 34(2): 11-14.
Keywords: tree/stand protection
tree/stand health
stand conditions
Abstract: In laboratory tests, pocket gophers (Thomomys and Geomys spp.) were offered 5
kinds of treated bait, including 1% Zn phosphide in oats, 0.75% Zn phosphide in fresh carrots,
and 0.5% strychnine in rolled oats (3 mixtures). The carrot bait was found to be as effective for
killing gophers as the strychnine mixtures. Plots in a 4-yr-old Pseudotsuga menziesii and Pinus
monticola plantation in Washington, with occupied T. mazama burrows, were baited with the
carrot or one of the strychnine mixtures in Nov. 1981. Both baits produced only a 63% reduction
in gopher activity, possibly because of the availability of abundant alternative vegetative food. It
was estimated that tree mortality due to root pruning by gophers was >10% on this site. It is
recommended that the carrot/Zn sulphide bait be registered for special local needs where safety to
wildlife and domestic animals is important.
344. Little, S.N. 1984. Weibull diameter distributions for mixed stands of western conifers. Canadian-
Journal-of-Forest-Research 13(1): 85-88.
Keywords: planting operations
growth
Abstract: The three-parameter Wiebull function was tested as a model for the diam.
distributions of mixed stands of western hemlock and Douglas-fir in Oregon. Weibull
distributions estimated by maximum likelihood (MLE) fitted 80 of 83 observed diameter
distributions at alpha =0.20 level of significance. Weibull parameter prediction equations were
developed by regressing characteristics of 42 stands against MLE of the parameters. The Weibull
diameter distributions predicted from stand age, mean diam., mean ht., and stand density fitted 39
of 41 observed distributions in the test group at the alpha =0.20 level of significance. These
results compared favourably with those found for various forest types by other authors.
345. Little, S.N. and D.R. Waddell. 1987. Highly stocked coniferous stands on the Olympic Peninsula:
chemical composition and implications for harvesting strategy. Pacific-Northwest-Research-
Station,-USDA-Forest-Service Research-Paper PNW-RP-384. 29 p.
Keywords: site preparation
mechanical preparation
soil properties
Abstract: An assessment is presented of macronutrients and their distribution within highly
stocked, stagnant stands of mixed conifers on the Quilcene Ranger District, Olympic National
Forest, northwest Washington, USA. These stands consisted of predominantly three species:
western hemlock (Tsuga heterophylla), coast Douglas fir (Pseudotsuga menziesii var. menziesii),
and western redcedar (Thuja plicata). Preliminary investigation suggested that the living crown
contained a small portion of the nutrient capital on the site. Extracting this material from the site
during harvest or site preparation should not pose a threat to future production of biomass.