Skip to main content

Incidence of Heterobasidion annosum in Mixed-Conifer Natural Regeneration Surrounding Large True Fir Stumps 20–25 Years after Harvesting in Northeastern Oregon

Buy Article:

$29.50 plus tax (Refund Policy)


High-elevation true fir stands on federal lands have a long history of selective harvesting. In 1989 a high frequency (89%) of Heterobasidion annosum, the cause of annosus root disease, was found in residual true fir stumps (mean, 20-in. diameter) cut 5–9 years earlier in northeast Oregon. In 2004, H. annosum was found at the stump surface of 29% of the natural conifer regeneration (mean, 18 years) within 20 ft of infected residual stumps. A total of 16 of 122 (13%) live saplings had H. annosum–caused stain or decay. Only 3% of 126 sample trees, however, were dead and infected by H. annosum. Infection was confirmed in 62% of decayed trees, 33% of stained trees, and 22% of trees with no visible stain or decay at the stump surface. Only 3 of 122 living saplings showed typical root disease crown symptoms (chlorosis), but only one of these had H. annosum. Only 1 of 16 live saplings with H. annosum–caused stain or decay was chlorotic. Incidence of infection was 44% in Engelmann spruce (7 of 16 trees), 31% in Douglas-fir (5 of 16 trees), 31% in subalpine fir (4 of 13 trees), and 27% in grand fir (21 of 77 trees). The S-type of H. annosum was confirmed in a sampled grand fir. There were no significant differences between H. annosum–infected and apparently healthy trees regarding live crown ratio and distance from infected residual stumps. Infected trees, however, were significantly (P = 0.025) larger in diameter than apparently healthy trees. The dynamics of H. annosum infection in spruce and Douglas-fir in northeast Oregon are discussed as well as treating true fir stumps with boron-containing products to prevent stump infection by H. annosum.

Keywords: Annosus root disease; Douglas-fir; Engelmann spruce; Umatilla National Forest; boron; grand fir; seed tree and selection harvesting; stain and decay; subalpine fir

Document Type: Research Article

Publication date: October 1, 2006

More about this publication?
  • Each regional journal of applied forestry focuses on research, practice, and techniques targeted to foresters and allied professionals in specific regions of the United States and Canada. The Western Journal of Applied Forestry covers the western United States, including Alaska, and western Canada; WJAF will also consider manuscripts reporting research in northern Mexico that has potential application in the southwestern United States.
  • Membership Information
  • Ingenta Connect is not responsible for the content or availability of external websites

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Partial Open Access Content
Partial Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more