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.
Lightning strikes appear as a long, narrow gouge down the side of the trunk.
Logging equipment may cause serious injury from bulldozers etc. scraping against trunks and removing portions of bark. Felling trees can cause injury as the falling tree removes branches from residual trees. Bark feeding by bears causes hundreds of millions of dollars' worth of damage. Pocket gophers can be a serious problem for regenerating conifer stands. The problem is particularly acute in ponderosa pine stands, as gophers prefer pine roots to other types of forage.