Mass Soil Erosion In Oregon

Brown describes mass soil erosion as “a catastrophic form of natural erosion and can be produced by road construction in unstable, steep topography”, one of the most common forms of erosion in Oregon due to poorly places logging roads. Not only does clearcutting in northern parts of Oregon create compacted roads, but when these mass soil movements occur along these roads that are built to transport the wood being taken out they flow right into river systems that can greatly affect the biotic factors living within the stream and can also lead to a faster rate of bank erosion in the future (Brown, 1914). The landscape and climate are very important factor of the northwest when talking about erosion rates because of the very rough topography of the region along with the precipitation amounts that occur there. Trees play a very important role in keeping the soils in place along the steep slopes of the Pacific Northwest. Annual precipitation may exceed 375 cm, so high volumes of vegetation and good infiltration rates of the soil …show more content…
Roots add strength to the soil by vertically stabilizing the soil to fractures in the bedrock and also laterally by tying weak portions of slopes together with stronger portions of the slope. In major areas of the Northwest root strength is the dominant factor in maintaining soil strength and combating against erosion (Swanston, Swanson. 1976). With this being said one of the main causes of erosion in the Northwest is due to clear cutting of trees and removing the root systems that hold the soil together. Bishop and Steven give a good example of how root systems help prevent erosion in their article Landslides on Logged Areas in Southeast Alaska, they report that on 67 percent slopes in Alaska both acreage and number of landslides increased fourfold after clearcutting of forests have taken place (Bishop,