George Weurthner, the ecological projects director for, , has written in Forest Magazine, outlining some of the research on why dead trees are good for forest ecosystems.
Among the tidbits from his essay: University of Montana ecologist Richard Hutto has found that about 45 percent of North American bird species depend on snags for at least part of their lives. Another researcher, Timothy Kent Brown, found that two thirds of all wildlife species use dead trees.
And not all dead trees are equal.
"William Laudenslayer, a U.S. Forest Service researcher at the Pacific Southwest Forest and Range Experimental Station, and his colleagues experimentally girdled trees to kill them, a common forestry practice used to produce snags for wildlife. They compared those snags to trees killed by bark beetles. They found that “bark beetle-killed trees provided significantly greater woodpecker feeding activity, cavity building and insect diversity” compared to snags created by girdling."
Via Ralph Maugham's Wildlife News.