Downed logs, especially those partially buried by duff or soil, act as moisture reservoirs. Salamanders and other amphibians seek shelter in the moist wood of decaying trees. Tree roots are commonly seen growing into decaying wood and seedling establishment is often enhanced by the availability of downed woody debris. Dead logs in and over streams enhance fish habitat. Nearly all species of fish living in streams use log cover at some stage in their life cycle.
Trout especially like to hide under fallen logs.
Some of these logs also provide basking spots for turtles. Standing dead trees are important because they provide nesting and resting sites for a variety of animals. About 45 species of birds that breed in Idaho use holes in dead trees as nest sites. About 30 species eat insects and are important in regulating the abundance of forest insects, including wood borers, bark beetles, budworms and tussock moth larvae. Included in this group is the mountain bluebird, our state bird.