介绍:
Reading
Every year, forest fires and severe storms cause a great deal of damage to forests in the northwestern United States. One way of dealing with the aftermath of these disasters is called salvage logging, which is the practice of removing dead trees from affected areas and using the wood for lumber, plywood, and other wood products. There are several reasons why salvage logging is beneficial both to a damaged forest and to the economy.
First, after a devastating fire, forests are choked with dead trees. If the trees are not removed, they will take years to decompose; in the meantime, no new trees can grow in the cramped spaces. Salvage logging, however, removes the remains of dead trees and makes room for fresh growth immediately, which i s likely to help forest areas recover from the disaster.
Also, dead trees do more than just take up space. Decaying wood is a highly suitable habitat for insects such as the spruce bark beetle, which in large numbers can damage live, healthy spruce trees. So by removing rotting wood, salvage logging helps minimize the dangers of insect infestation, thus contributing to the health of the forest.
Third and last, salvage logging has economic benefits. Many industries depend upon the forests for their production, and because of this a fire can have a very harmful effect on the economy. Often, however, the trees that have been damaged by natural disasters still can provide much wood that is usable by industries. Furthermore, salvage logging requires more workers than traditional logging operations do, and so it helps create additional jobs for local residents.
Listening
Professor:
Salvage logging may appear to be an effective way of helping forests recover after a destructive fire or storm, but it can actually result in serious longer-term environmental damage. Its economic benefits are also questionable.
First, cleaning up a forest after a fire or storm does not necessarily create the right conditions for tree growth. In fact, the natural process of wood decomposition enriches the soil and makes it more suitable for future generations of tree. The rapid removal of dead trees can result in soil that lacks the nutrients necessary for growth.
Second, it's true that rotting wood can increase insect populations, but is this really bad for the forest? In fact, spruce bark beetles have lived in Alaskan forest for nearly a hundred years without causing major damage. And of course dead trees do not provide habitats only for harmful insects. They are also used by birds and other insects that are important contributors to the long-term health of forests. In the long run, therefore, salvage logging may end updoing more harm to forests than harmful insects do.
And third, the economic benefits of salvage logging are small and don’t last very long, in severely damaged forests, much of the lumber can be recovered only by using helicopters and other vehicles that are expensive to use and maintain. Furthermore, jobs created by salvage logging are only temporary and are often fitted by outsiders with more experience or training than local residents have.
