Canadian Forest Service Publications

Heart rot of Jack pine in Ontario. III. Decay relationships and their effects on management. 1967. Basham, J.T. The Forestry Chronicle, 43:222-238.

Year: 1967

Issued by: Great Lakes Forestry Centre

Catalog ID: 33577

Language: English

Availability: PDF (request by e-mail)

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A total of 4,287 jack pine (Pinus banksiana Lamb.) trees were sampled throughout most of the range of this species in Ontario. Tree age was the factor associated with the greatest variation in the extent of defects of fungal origin (decay) within the merchantable bole. The amount of decay increased with host age, accelerating markedly after 90 to 100 years. A close relationship also was found between the extem of defective jack pin'e heartwood and three geographical regions of the Province. Roughly twice as much decay, on a volume percentage basis, was encountered in western Ontario as in eastern Ontario. A tendency for more decay to occur iii relatively slow growing jack pine was observed; however, this was not statistically significant. Site, based on soil moisture regime, was related to the incidence of decay in the sample trees. There is evidence from this and other investigations that the growth rate of jack pine is highest on moderately dry to moc/erately fresh sites with soil moisture regimes 2 or 3. Most jack pine in Ontario occurs on very dry or dry soil moisture regimes 0 or 1. The extent of decay was significantly less on regimes 2 and 3 which represent the optimum sites for jack pine quality and growth in Ontario.