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

80. Cameron, I.R. 1988. An evaluation of the density management diagram for coastal Douglas-fir.
BC Ministry of Forests FRDA-Report 024. vi + 17 p.
Keywords: planting operations
growth
yield
Abstract: Yield predictions based on Drew and Flewelling's (1979) density management
diagram for coastal Douglas fir (Pseudotsuga menziesii) were compared with remeasured plot
data from British Columbia. The diagram overestimated standing volume by 64% and mean
diameter by 24% on average. Volumes predicted for plantations established at initial densities
between 300 and 3000 trees per hectare exceeded nearly all the plots in the database. Because of
the unattainable production targets set by the diagram, strategic plans based on its predictions
would be seriously in error. Consequently, the diagram cannot be used in its current form as a
silvicultural planning tool in stands of Douglas fir on the coast of British Columbia.
81. Campbell, D.L. and J. Evans. 1988. Recent approaches to controlling mountain beavers
(Aplodontia rufa) in Pacific Northwest forests. In Proceedings: Thirteenth Vertebrate Pest
Conference, Monterey, California. pp. 183-187.
Keywords: tree/stand protection
tree/stand health
Abstract: Investigations by the Denver Wildlife Research Center into ways of managing
mountain beaver (Aplodontia rufa) populations are described. Methods were developed for
alleviating mountain beaver damage to conifer trees being grown for timber in the Pacific
Northwest. Studies initiated in 1986 indicated that aversive conditioning with Big Game
Repellent Powder (BGR-P) dusted on culled Douglas fir (Pseudotsuga menziesii) seedlings
placed in burrows significantly reduced mountain beaver damage to planted seedlings treated
with BGR-P and to untreated seedlings. Trials also showed that strychnine-sword fern
(Polystichum munitum) baits prepared with a 4.9% (active) strychnine paste concentrate were
very effective and selective for mountain beaver control. Other topics discussed are the results of
several probes with toxic baits and phosphine gas, trials with a drug (reserpine) and a wetting
agent to induce hypothermia, and destruction of underground nests to prevent reinvasion.
82. Campbell, S.J. and P.B. Hamm. 1989. Susceptibility of Pacific Northwest conifers to
Phytophthora root rot. Tree-Planters'--Notes 40(1): 15-18.
Keywords: nursery operations
tree/stand protection
tree/stand health
Abstract: One-yr-old bare-rooted seedlings of 11 conifer species were inoculated with (a)
Phytophthora cactorum, (b) P. cryptogea, (c) P. drechsleri, (d) P. megasperma or (e) P.
pseudotsugae. Development of above-ground symptoms and root disease was followed for 10 wk.
Isolates of (a), (b) and (e) caused the most overall mortality and isolates of (d) the least. Pinus
contorta, P. ponderosa, P. monticola, Larix occidentalis, Libocedrus decurrens, Picea sitchensis
and P. engelmannii showed tolerance to the root disease, Abies grandis and Pseudotsuga
menziesii showed intermediate susceptibility and A. magnifica and Tsuga mertensiana were quite
susceptible. Results are discussed in relation to management of conifer nurseries in the Pacific
Northwest.
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