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Dead and Down Woody Material
(Taken from Wildlife Habitats in Managed Forests 
the Blue Mountains of Oregon and Washington)

by Chris Maser Ralph G. Anderson Kermit Cromack, 
Jr. Jerry T. Williams Robert E. Martin

Dead and down woody materials have long been viewed by foresters as unsalvaged mortality, the utilization of which is an important objective of good timber management. This material is also viewed as a fire hazard, and steps are frequently taken to reduce the amount of flashy fuels from timber harvest areas. Woody materials are also recognized as home for small vertebrate animals that are considered "pests" which impede reforestation.

These are all valid considerations, but dead and down woody material in various stages of decay serves many important functions, one of which is habitat for wildlife. Instead of viewing logs left in a forest as unsalvaged mortality or a fire hazard, this chapter examines their role as wildlife habitat. Elton (1966, p. 279) put it this way:

When one walks through the rather dull and tidy woodlands--say in the managed portions of the New Forest in Hampshire [England]-that result from modern forestry practices, it is difficult to believe that dying and dead wood provides one of the two or three greatest resources for animal species in a natural forest, and that if fallen timber and slightly decayed trees are removed the whole system is gravely impoverished of perhaps more than a fifth of its fauna.

Logs and other woody debris, such as stumps, root wads, bark, and piles of limbs, occur on the floor of most forest ecosystems. These features provide diversity in the environment and are of varying significance as habitat for terrestrial wildlife (Winn 1976) (figs. 42 and 43). In the Blue Mountains 179 species of vertebrates (5 amphibians, 9 reptiles, 116 birds, and 49 mammals) make some use of logs. Elton (1966, p. 279) said that in England:

... indexes of the Ecological Survey contain 456 species of animals [including invertebrates] at Wytham living in wood or under bark where decay has begun or already gone far. Another 518 species are known to occur in this habitat elsewhere in Britain....

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