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thinning trees when less than 15 years old, by cutting only trees less than 10 cm in diameter and
by thinning during low risk seasons.
421. Morrison, D.J., M.D. Larock and A.J. Waters. 1986. Stump infection by Fomes annosus in spaced
stands in the Prince Rupert Forest Region of British Columbia. Pacific-Forestry-Centre,
Canadian-Forest-Service Information-Report BC-X-285. 12 p.
Keywords: thinning
tree/stand protection
tree/stand health
Abstract: Discs 3-5 cm thick were collected after removal of the top 5-10 cm from stumps
left by thinning 1-8 yr previously of 12- to 37-yr-old stands of 5 coniferous species, and the
occurrence and area of surface colonization with F. annosus [Heterobasidion annosum] were
measured. Based on the % of stumps with more than 10% of their area colonized, susceptibility
decreased in the sequence Abies amabilis, Picea sitchensis, Tsuga heterophylla, Pseudotsuga
menziesii; Pinus contorta was unaffected. Fewer stumps were colonized in a T. heterophylla/A.
amabilis stand thinned in winter than in an adjacent stand thinned in late spring: the difference
was attributed to effects on spore populations of low temp. and heavy precipitation. There was a
significant correlation between % stump area colonized and % root vol. colonized by H. annosum
for A. amabilis and T. heterophylla. H. annosum had spread from colonized roots on some
excavated stumps to or into adjacent roots of reserved trees.
422. Muller, C., E. Falleri, E. Laroppe and M. Bonnet Masimbert. 1999. Drying and storage of
prechilled Douglas fir, Pseudotsuga menziesii, seeds. Canadian Journal of Forest Research
29:172-177.
Keywords: nursery operations
reproduction
Abstract: Douglas fir, Pseudotsuga menziesii, seeds exhibit relative dormancy as they do
not germinate at suboptimum temperature (15°C), whereas at optimum temperature (20°C) some
germination occurred. Thus, germination at 15°C was chosen to estimate dormancy release. In the
first experiment, seeds were prechilled at 32% moisture content (MC) for 0-34 weeks at 3°C.
Long chilling treatments enhanced germinability and, more markedly, germination speed both at
20°C and at 15°C. Seeds pretreated for the longest periods were then dried to 6.7% MC and
stored up to 6 months without any detrimental effect on germination at 15°C. In the second
experiment, seeds from a second seedlot were prechilled for 18 weeks and then stored at three
different MCs (6.7, 7.2 and 8.1%) over a period of 17 months. Seeds stored at the lowest MC
germinated fastest and to the highest percentage both at 15 and 20°C. In the nursery, seedling
emergence tests confirmed results from this experiment.
423. Murray, M.D. 1988. Growth and yield of a managed 30-year-old noble fir plantation. Pacific-
Northwest-Research-Station,-USDA-Forest-Service Research-Note PNW-RN-475. 8 p.
Keywords: planting operations
growth
yield
economics