Skip to page content
USDA Forest Service
  
Treesearch

Research & Development Treesearch

 
Treesearch Home
About Treesearch
Contact Us
Research & Development
Forest Products Lab
International Institute of Tropical Forestry
Northern
Pacific Northwest
Pacific Southwest
Rocky Mountain
Southern Research Station
Help
 

Science.gov - We Participate


USA.gov  Government Made Easy


Global Forest Information Service

US Forest Service
P.O. Box 96090
Washington, D.C.
20090-6090

(202) 205-8333

You are here: Home / Search / Publication Information
Bookmark and Share

Publication Information

View PDF (116 KB bytes)

Title: Characteristics and consequences of root diseases in forests of Western North America

Author: Goheen, D.J.; Otrosina, W.J.;

Date: 1998

Source: In: Frankel, Susan J., tech. coord. User’s guide to the western root disease model, version 3.0. Gen. Tech. Rep. PSW-GTR 165. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Station: 3-8.

Publication Series: Miscellaneous Publication

Description: Root diseases are somewhat mysterious. Operating as they do within the soil, it is difficult to actually view root pathogens or follow their progress in causing disease. The signs and symptoms that they produce can be quite subtle and variable. Just identifying which pathogen occurs in a specific situation is often challenging. Nevertheless, in the past two decades, forest managers have become increasingly aware of the important roles that root disease organisms play in forests and the significant influences that they exert on the ability to attain desired management objectives. Root pathogens usually affect groups of neighboring trees in progressively expanding disease pockets or centers. These centers generally contain dead trees that have died at different times over several years and living but infected trees in various stages of decline. They are commonly characterized by much lower stocking levels than surrounding healthy portions of stands, and they also may contain numerous windthrown or broken trees on the ground. Root disease centers vary in size from those involving only a few trees to those covering hundreds of acres. They may be very discrete or they may involve a scattering of affected trees dispersed over a larger area.

On individual trees, crown symptoms associated with most root diseases are similar and include reduced height growth, loss of needles, chlorotic foliage, death of branches, production of distressed cone crops, and, ultimately, host mortality. Accurate identification of which root pathogen or pathogens occur in an area usually requires digging to expose roots, and removing bark from roots and root collars to reveal the inner wood. Often laboratory culturing or more sophisticated techniques such as isozyme and DNA analyses are necessary to identify the biological species or strain of the causal fungi. Although a number of root diseases are found in the West, three are considered to be the most significant. These are laminated root rot, caused by the fungus Phellinus weirii; Armillaria root disease, caused by Armillaria ostoyae; and Annosus root disease, caused by Heterobasidion annosum. The impacts of these fungi on forest stands are modelled in the Western Root Disease Model, Version 3.0. A general understanding of their biology is presented to enhance the reader's ability to input data and interpret outputs.

Publication Notes:

  • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
  • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
  • You may send email to pubrequest@fs.fed.us to request a hard copy of this publication. (Please specify exactly which publication you are requesting and your mailing address.)

XML: View XML

Citation:


Goheen, D.J.; Otrosina, W.J. 1998. Characteristics and consequences of root diseases in forests of Western North America. In: Frankel, Susan J., tech. coord. User’s guide to the western root disease model, version 3.0. Gen. Tech. Rep. PSW-GTR 165. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Station: 3-8.

 


 [ Get Acrobat ]  Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility

USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.