1995 FOREST DISTURBANCE IN OREGON 



Root diseases & dwarf mistletoes 

 continue to cause subtle but 

 significant mortality and growth 

 losses. Swiss needle 

 cast on the coast 



IS a concern. 



Pollution from Portland 

 and other urban areas has 

 long-range effects on 

 lichens and forest 

 vegetation. 



Fire suppression 

 contributes to 

 overstocking, 

 species changes, 

 and increased risk 

 of disturbance 

 (fire, insects, 

 diseases). Over- 

 stocked stands 

 experiencing bark 

 beetle outbreaks. 



Western spruce 

 budworm and 

 tussock moth 

 outbreaks collapse 

 throughout state. 



New introductions of gypsy 

 moth in 1995. Established 

 exotics — balsam woolly adelgid, 

 white pine blister rust, 

 and Port-Orford-cedar 

 root disease — 

 continue to 

 kill trees. 



Pandora 

 moth 

 outbreak 

 collapses. 



Drought effects seen from the 

 past decade of below-normal 

 precipitation. Winter windstorms 

 and flooding cause localized mortality. 



Drought in the 

 late 1 980s and 

 early 1990s 

 contributes 

 to moisture 

 stress In over- 

 stocked stands. 



Overstocked 

 stands are 

 experiencing 

 bark beetle 

 outbreaks 

 and increased 

 insect and fire 

 susceptibility 

 — aggravated 

 by drought. 



Root disease 

 and mistletoe 

 losses increase 

 where fire 

 suppression and 

 past harvest 

 practices have 

 increased hosts. 



Fir engraver 

 and drought 

 cause mortality 

 in overstocked 

 white fir stands. 



Oregon — 24 



