On seedlings and saplings, clipped tops and branches from deer or snowshoe hare browsing. Holes in trunk caused by woodpeckers or sapsuckers. Sudden browning of foliage, particularly in spring after winter feeding. Damage from insects or disease. Feeding damage is extensive in the spring before other food sources are available, and bears seem to prefer fast-growing trees of all species.
Porcupines eat the inner tree bark, often climbing the tree to reach the thinner, smoother bark.
They may partially or completely girdle the tree. Deer and elk browse the tips and branches of young seedlings and saplings, seeming to prefer Douglas-fir. Snowshoe hares and rabbits clip off branches and stems of seedlings. Mechanical damage occurs as a result of weather events and human activities. Major storms with severe winds can cause windthrow.