Willamette Basin forests are suffering from a diminishing energy supply and a loss of ecosystem services. Forest practices are associated with increased soil erosion and landslides. With disturbed soils, watershed productivity has historically

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• Effects of Meager Logging Techniques and
  Construction of Roads on the Environment
• Use of heavy equipment and high traffic creates
  soil compaction
• Leads to a diminishing rate of re-growth
• Kills off root systems
• Secretion of ground water and nutrients creating
  a lower porosity of soils
• Contributes to mass wasting
• Clearcutting destroys the environments ability
  to regulate geomorphic
  
  
  processes
• Leaching of valuable recourses like Nitrogen,
  Phosphorous, and Magnesium
• Diminishes water absorption
• Removes protection from stream banks
• Reduces hill side cohesion of soils

Relationships of Environmental Impacts In
analysis of an area of the H.J. Andrews
Experimental Forest on Land below 1000 meters
with predominantly altered volcanclastic geology
two areas were evaluated for environmental
impacts of forest management practices. One area
was forested land untouched by man, and the other
was 25.6 clear cut with 5 of the land road
rights-of-way. The result of the study show that
the clear cut land had 30 times the amount of
slide erosion than the forested area.
INTRODUCTION Willamette Basin forests are
suffering from a diminishing energy supply and a
loss of ecosystem services. Forest practices are
associated with increased soil erosion and
landslides. With disturbed soils, watershed
productivity has historically experienced
declining trends. In order to maintain optimum
levels of forest production, balanced by
minimized geomorphic effects, alterations in
forest practice is a necessity. This paper
examines the relationship between timber
harvesting methods and erosion processes in
upland basins of the Western Cascades. The
effects of road construction and clear-cutting
are examined.

• Composition of Pacific Northwest Forests
• Primarily composed of evergreen coniferous
  trees
• Adapted to winter-wet and summer-dry
  environment
• Small streams in forest watersheds comprise 86
  of all river channels in the U.S.
• Forests supply energy, minerals, shade and
  stability of soils, thus regulating the rate of
  stream production
• Erosion from unstable soils affects the
  stability of substrates and the leaching of
  nutrients

Erickson Air-Crane removing logs from an Oregon
hillside
Siskiyou, Oregon Clear-cut project

• Conclusions
• The most desirable logging techniques include
• Thinning with minimal road construction
• Limit logging to periods when soils are
  predominantly dry
• Use low impact equipment
• Create culverts to maintain drainage from streams
• Leave buffers around streams
• Replant trees and shrubs
• Rotation of regions that do get logged
• These techniques are growing in
  popularity as concerns for geomorphic processes
  are growing. Logging practices have changed
  dramatically throughout Oregon's history and
  continue to seek improvement.

• Alternative Logging Practices
• Limit logging to dry grounds
• Limit the amount of roads created
• Use selective cutting/thinning techniques
• Leave stream buffers to preserve integrity
• Use low impact equipment
• Lighter weight/wider wheel base
• Alternative equipment
• Air-cranes
• Replant trees and shrubs
• Fertilize

• History of Oregons Logging Industry
• Economic boom from WWII increased timber demand
  and continued through the 1940s and 1950s
• Clearcutting was dominate practice
• Trees were either yarded out or skidded with a
  Cat
• Streams were redirected to increase flow and
  over powered by log transfers
• Logging roads prevailed throughout the terrain
• Minimal restrictions on logging

References Cited K. Cromack, Jr., F.J. Swanson
and C.C. Grier. A Comparison of Harvesting
Methods and their Impact on Soils and Environment
in the Pacific Northwest. 1979, U.S. Department
of Agriculture F.J. Swanson, C.T. Dyrness.
Impact of Clear-Cutting and Road Construction on
Soil Erosion by Landslides in the Western Cascade
Range, Oregon. 1975, The Geology Society of
America.