Also included is more than 2.8 million acres of state land, and about 16 million acres of private industrial and non-industrial forest land. East of the Cascades Outbreaks of defoliating insects, such as western spruce budworm and Douglas-fir tussock moth, are now larger, more intense, and more frequent. Bark beetle mortality, associated with tree stress and overstocked stands, is more prevalent. Drought periods in the late 1980s and early 1990s, coupled with overstocking, contributed to increased susceptibility to insects, diseases, and fire. Many root diseases and dwarf mistletoes are more widespread and destructive because of changes in forest structures and past harvest practices.
Fire is less frequent now but much more devastating on lower elevation, dry sites.
The fire hazard on these sites is higher because of fuel buildup . West of the Cascades Incidence and damage by native forest pathogens, particularly root disease have increased because of past forest management practices. Introductions of exotic pests have risen dramatically over the past century with increased commerce, travel, and new people moving to the Northwest. Air pollution has worsened in the Willamette Valley and Puget Sound areas with increased population and industry. Ozone and other pollutants can damage forests near and far from pollutant sources.