Coarse woody debris
[3] Since the 1970s, forest managers worldwide have considered it best environmental practice to allow dead trees and woody debris to remain in woodlands, recycling nutrients trapped in the wood and providing food and habitat for a wide range of organisms, thereby improving biodiversity.
[2] Coarse woody debris comes from natural tree mortality, plant pathology, insects, wildfire, logging, windthrows and floods.
[citation needed] Ancient, or old growth, forest, with its dead trees and woody remains lying where they fell to feed new vegetation, constitutes the ideal woodland in terms of recycling and regeneration.
[5] Coarse woody debris and its subsequent decomposition recycles nutrients that are essential for living organisms, such as carbon, nitrogen, potassium, and phosphorus.
[11] Colonizing organisms that live on the remains of cambium and sapwood of dead trees aid decomposition and attract predators that prey on them and so continue the chain of metabolizing the biomass.
[citation needed] The list of organisms dependent on CWD for habitat or as a food source includes bacteria, fungi, lichens, mosses and other plants, and in the animal kingdom, invertebrates such as termites, ants, beetles, and snails,[13] amphibians such as salamanders,[12] reptiles such as the slow-worm, as well as birds and small mammals.
[citation needed] Fallen debris and trees in streams provide shelter for fish, amphibians and mammals by modifying the flow of water and sediment.
[18] CWD of 3 to 8 inches (8 to 20 cm) in diameter is classified as 1000-hour fuel by fire managers, referring to the amount of time needed for the moisture content in the wood to come to equilibrium with the surrounding environment.
[1] In certain subtropical areas such as Australia where bushfire constitutes a major hazard, the amount of CWD left standing or lying is determined by what may be considered safe in the course of reasonable fire prevention.
[citation needed] In Canada, bears seek out dead tree logs to tear open and look for and feed on ants and beetles, a fact that has encouraged the authorities to reserve a sufficient amount of coarse woody debris for these purposes.
