UNIVERSITY PARK, Pa. -- Most people recognize the importance of living trees, but too many don't see the value of dead trees, according to a Penn State forestry expert.

Most everyone knows that living trees provide wildlife habitat, oxygen, timber, beauty and many other assets. But many believe that when a tree dies, it is no longer useful. "One misconception is that when a tree's vigor deteriorates, so does its ability to provide benefits," says Rance Harmon, extension forest resources specialist. "In fact, my American Heritage Dictionary defines deadwood as 'anything burdensome or superfluous.' Those certainly are not the qualities of something a landowner would want to have around."

Harmon contends that dead and deteriorating trees actually are vital elements of healthy forests. They release nutrients, prevent erosion, store moisture, protect seedlings and supply food and shelter for wildlife. "Despite their importance, the number of dead and dying trees in some forestlands has declined due to timber salvaging, fire prevention, firewood cutting and worker safety regulations," he says. "Good forest stewardship requires us to consider both living trees and deadwood as vital, interacting components of the forest ecosystem that we can manage to meet sustainable forestry objectives."

As a tree's health deteriorates, it begins to lose the battle against invading organisms and the wood becomes weaker and softer -- ideal for cavity excavators such as woodpeckers. "Many wildlife species use tree cavities for sanctuary against predators, extreme temperatures and unfavorable weather conditions, and for nesting and brooding," says Harmon.

"Cavity nesters play a significant role in forest ecosystems by preying on harmful insects and helping to disperse seeds. Wood ducks, bluebirds, woodpeckers, owls, chickadees, squirrels, raccoons, bats and mice are among the 35 species of birds and 20 species of mammals that use tree cavities in Pennsylvania."

Standing dead trees (snags) not only provide cavities but also are favorite perching sites for flycatchers, hawks and owls, according to Harmon. "Along the water's edge, snags are excellent places to find perching kingfishers, ospreys and bald eagles," he says. "Nuthatches and some bats and salamanders use spaces between loose bark and tree trunks for roosting. Woodpeckers produce audible reminders of the importance of deadwood for wildlife by using the resonant qualities of deadwood for drumming -- a communication technique used to indicate territorial boundaries and attract mates."

Dead trees retain their ability to benefit wildlife and contribute to forest health even after they fall to the ground, Harmon points out. "Downed, decaying wood provides cover, foraging habitat and egg laying sites for salamanders; and secure winter travel corridors and thermal protection for small mammals and mustelids, such as weasels," he says. "Twenty-three species of amphibians and reptiles take refuge in decaying wood in the northeastern United States, including box turtles and snakes."

By providing habitat and nutrition for organisms such as fungi, centipedes, beetles and ants -- which, in turn, provide food for larger animals such as skunks, bears and woodpeckers -- Harmon notes that deadwood plays a key role in forest food webs. "Besides directly benefiting wildlife, deadwood plays an important role in forest health by promoting soil fertility," he says. "As they decompose, rotting logs slowly release nutrients that help nurture future tree growth and prevent erosion by holding soil in place. The branches and tops of fallen trees help enable the regeneration of forests by protecting new tree growth from animal browsing."

Woody debris also plays a critical role in aquatic environments. Logs and branches that fall into steams and rivers help diversify habitat by creating deep pools, shady areas and shelter. "Aquatic habitats with sufficient woody debris support a greater variety of fish, invertebrates, algae and other organisms than habitats devoid of woody debris," Harmon says. "Besides habitat, logs can protect stream banks and lakeshores from erosion and trap leaves, which, together with deadwood, are the major source of nutrients for small streams."

Harmon stresses that good forest stewardship involves regarding dead and deteriorating trees as vital elements of healthy forests to manage for sustainable forestry objectives. For more information about deadwood, get the free publication, Pennsylvania Woodlands Number 7: Dead Wood for Wildlife from the Forest Stewardship Program by calling 1-800-235-WISE, sending e-mail to RNRext@psu.edu, or writing: Forest Stewardship Program, Forest Resources Extension, The Pennsylvania State University, 7 Ferguson Building, University Park, PA 16802.

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EDITORS: Rance Harmon can be contacted at 814-863-0401 or rsh144@psu.edu.

Contact: Jeff Mulhollem jjm29@psu.edu 814-863-2719 814-863-9877 fax #289