Mixed conifers PNW, PSW' InlandWest Changes in fire regimes and historical high-grade logging have led to large areas of dense stands. Savanna and complex structures are lacking in many areas, and the amount and arrangement of dead fuels can lead to lethal crown fires that will foreclose their development for centuries. The exotic white pine blister rust has nearly wiped out the species across its range. Resistant strains have been selected and planted, but there is worry about the narrow genetic base being used. Lack of open structures and reduced meadow area affects diversity and increases risk of landscape-level wildfires.
Wildfires are no more lethal than historical, but less frequent, and much larger when they happen.
Only fragments remain. Exotic species have replaced most natives, often by more aggressive growth following hurricane disturbances. Aspen InlandWest Fire suppression has allowed conifers to invade, while heavy elk and deer browsing has limited regeneration. The aggressive root system eliminates grass, making prescribed fire difficult. Most people live in the valleys, where they rely on mountain watersheds for municipal, agricultural, and power-generating water.