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The Value of Dead Trees
by George Wuerthner
There's an old cliche that one can't see the forest for the trees. It is used to describe people who are so focused on some detail that they fail to see the big picture. Nowhere is this failure to see the forest for the trees more evident than the rush to utilize dead trees for biomass fuels and/or the presumed need to "thin" forests to reduce so-called "dangers" and/or "damage" from wildfire and beetle outbreaks.
Dead trees are not a "wasted" resource. An abundance of dead trees, rather than a sign of forest sickness as commonly portrayed, demonstrates that the forest ecosystem is functioning perfectly well. For far too long we have viewed the major agents responsible for the creation of substantial quantities of dead trees - beetles and wildfire - as "enemies" of the forest, when in truth they are the major processes that maintain healthy forest ecosystems.
An abundance of dead trees...demonstrates that the forest ecosystem is functioning perfectly well.
Grizzly bear cub, Ursus arctos horribilis. George Wuerthner
Recent research points out the multiple ways that dead trees and down wood are critical to the forest. One estimate suggests that two-thirds of all species depend on dead trees/down wood at some point in their lives.
Once a tree falls to the ground and gradually molders back into the soil, it provides home to many small insects and invertebrates that are the lifeblood of the forest, that help recycle and produce nutrients important for present and future forest growth. For instance, there are hundreds of species of ground-nesting bees that utilize down trees for their home. These bees are major pollinators of flowers and flowering shrubs in the forest.
Ants are among the most abundant invertebrates in the forest and many live in down trees and snags. Ants play a critical role in the forest, helping to break down wood, aerate soil with their burrows, and protect trees against the onslaught of other insects. One study found that ants killed 85% of the tussock moths that attacked Douglas fir, and there are many other examples of how ants protect trees from tree predators.
Logs in Ohanapecosh River from flood Mt Rainier National Park, Washington. George Wuerthner
Logging, thinning, biomass removal and other forest management introduce all kinds of negative impacts to the forest ecosystem, from the spread of weeds to soil compaction, alteration of water flow, disturbance to wildlife, creation of new off-road vehicle trails, and increases in sedimentation. These negative impacts all lead to the degradation of the forest ecosystem itself, and most are ignored or glossed over by proponents of thinning and biomass removal.
Forest "management" is so focused on trees and wood products that it represents a critical failure to see the forest through the trees.
George Wuerthner is editor of Wildfire: a Century of Failed Forest Policy.
[16 dec 09]