HEART ROT OF JACK PINE IN ONTARIO: I. THE OCCURRENCE OF BASIDIOMYCETES AND MICROFUNGI IN DEFECTIVE AND NORMAL HEARTWOOD OF LIVING JACK PINE

Abstract

A survey was made of the fungi inhabiting the heartwood of living jack pine (Pinus banksiana Lamb.) in Ontario, particularly in stained and decayed wood. Two Basidiomycetes encountered frequently were Fomes pini (Fr.) Karst., associated with red stain and white pocket rot, and Peniophora pseudo-pini Weres. & Gibson, isolated almost exclusively from stained wood. F. pini was the only fungus consistently associated with white pocket rot, the principal type of heart rot in jack pine. The three most abundant microfungi, a member of the Coryne sarcoides complex, Tympanis hypopodia Nyl., and Retinocyclus abietis (Crouan) Groves & Wells, were encountered frequently in stained wood, but less frequently in decayed and normal wood.Many aspects of the occurrence of these five fungi in jack pine were investigated, including their distribution in the stems and branch stubs of individual trees and their association with normal, stained, and decayed wood therein; and the relation between their occurrence and tree growth rate, various heartwood properties, and different stand conditions. The apparent means by which the fungi enter jack pine, and the possible existence of a succession of fungi in the heartwood of living trees, are discussed.