Laminated Root Rot Forest Health Stand Establishment Decision Aid

Abstract

Laminated root rot (Phellinus weirii) is the most prominent root disease of Douglas-fir in coastal coniferous forests and is endemic throughout its host's range in British Columbia. The disease spreads primarily via root contact and can attack and gradually kill trees throughout their life cycle. It can lower stand volume by 40–70% on infected sites and acts as a stand-altering disturbance agent. The retention of infected stumps and residual trees (via partial cutting) can perpetuate the incidence of laminated root rot in a regenerating stand by leaving material on site to act as reservoirs of disease. To mitigate disease impact, a good understanding of the distribution and biology of P. weirii is necessary. The cedar form of P. weirii, which is responsible for a butt rot in western redcedar, is not covered in this extension note.

The Stand Establishment Decision Aid (SEDA) format has been used to extend information on various vegetation and forest health concerns in British Columbia. This decision aid summarizes information that relates current management regimes to the spread and effects of laminated root rot. The first page provides general information, hazard ratings for some of the biogeoclimatic zones and subzones of the Coast Forest Region, and silvicultural considerations for laminated root rot. The second page outlines the growth and yield implications and other effects and associations of the disease. This page also includes a valuable resource and reference list to provide readers with more detailed information. Reference material that is not available on-line can be ordered through libraries or the Queen's Printer at: www.qp.gov.bc.ca.