erosion
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When topsoil has eroded, it is much harder for new plants to grow, and the lack of stabilizing plant roots leads to more erosion. Once erosion begins, it is very hard to repair the damage. In major landslides, all the soil right down to the bedrock is carried downslope, taking all the trees and other vegetation with it. Since no soil is left for new plants to grow, the bare tracks of landslides remain visible for hundreds of years. Erosion is therefore a serious long-term threat to forests -- without soil, vegetation cannot grow. After a landslide, hundreds of years are required before enough new soil accumulates to replace the former layer of topsoil and organic material.
landslides Above and Right: Landslides that began from a logging road partway up a mountainside. The soil slid right down into the lake below, leaving the bedrock exposed. Photos courtesy Al Walters.
landslide
Eroded soil is often washed into streams and rivers. Fish and other freshwater animals need clear water, and this eroded soil destroys their habitat. Many forest streams that were once spawning areas for salmon have been ruined by silt. Often these streams run near clearcuts, which can be areas of extensive erosion because of their loss of tree cover.

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erosion -- page 3 of 3
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related topics
[soil] [water] [riparian zones] [fish] [amphibians]

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