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 (6.4 MB)

Title: Oak decline around the world

Author: Gottschalk, Kurt W.; Wargo, Philip M.;

Date: 1997

Source: In: Fosbroke, S.L.C.; Gottschalk, K.W., eds. Proceedings, U.S. Department of Agriculture interagency gypsy moth research forum 1996; 1996 January 16-19; Annapolis, MD. Gen. Tech. Rep. NE-230. Radnor, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station: 3-13.

Publication Series: Paper (invited, offered, keynote)

Description: Oak (Quercus spp.) decline is a malady related to the consequences of stress and successful attack of stressed trees by opportunistic (secondary) organisms (Wargo et al. 1983). It is a progressive process where trees decline in health for several years before they die. Houston (1981) developed a model of declines that is presented in Figure 1. So what is stress? It is pressure that brings ahout changes in a tree's physiology, form, or structure that predispose it to invasion by organisms that it ordinarily can resist. Stress can be biotic (defoliation by insects or fungi), abiotic (frost damage, defoliation by frost, drought, excess moisture, air pollution), or stand dynamics/life stage induced (low vigor due to competition or age). So what are secondary organisms? They are biotic agents, usually insects or fungi, that normally attack weakened trees and kill them but rarely can successfully attack healthy trees. These organisms play an important ecological role by killing trees that are weakened due to competition or other natural processes. Due to the numerous stress agents that can affect oak forests, oak decline can occur simultaneously in many different geographic areas, be triggered by entirely different or identical stress agents, and result in death of oaks from a wide variety of organisms.

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.
  • This publication may be available in hard copy. Check the Northern Research Station web site to request a printed copy of this publication.
  • Our on-line publications are scanned and captured using Adobe Acrobat. During the capture process some typographical errors may occur. Please contact Sharon Hobrla, shobrla@fs.fed.us if you notice any errors which make this publication unusable.

XML: View XML

Citation:


Gottschalk, Kurt W.; Wargo, Philip M. 1997. Oak decline around the world. In: Fosbroke, S.L.C.; Gottschalk, K.W., eds. Proceedings, U.S. Department of Agriculture interagency gypsy moth research forum 1996; 1996 January 16-19; Annapolis, MD. Gen. Tech. Rep. NE-230. Radnor, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station: 3-13.

 


 [ 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.