Incidence of Decay Fungi in Stumps of Two Thinned Western Larch Stands in Northeastern Oregon

摘要

Incidence of decay fungi was measured in stumps from two thinned western larch (Larix occidentalis Nutt.) stands (9 and 15 years after thinning), one precommercially thinned and one commercially thinned, in northeastern Oregon. Ten species of decay fungi were postively identified from 180 stumps. Two root pathogenic species, Heterobasidion annosum (Fr.) Bref. and Armillaria obscura (Pers.) Herink Roll-Hansen, were found at relatively low frequencies. Most of the decay in the stumps was caused by either Fomitopsis pinicola (Swartz ex Fr.) Karst. or Trichaptum abietinum (Dicks. ex Fr.) Ryv., which normally are saprophytic wood decomposers.