Effects of logging in stream and river buffers on watercourses and water quality in the southern forest of Western Australia

Summary During the summers of 1984/85 and 1985/86 several stream and river buffers were logged in the southern forest of Western Australia to assess the effects on the watercourses and water quality. All cut-over areas were regenerated to forest soon after logging. Reducing the width of river buffers from the usual 200 m to 100 m (3 trials), and reducing the width of stream buffers from the usual 100 m to 50 m (2 trials) had no effect on the watercourses or water quality. The complete removal of stream buffers (1 trial) introduced logging debris to the stream channel and led to minor changes in the stream channel profile and algal blooms. However, it had no detectable effect on suspended sediment concentrations in the stream. In all six trials some minor erosion occurred on the boundary tracks. In two trials major logging roads crossed a stream. At these crossings organic matter and road surfacing material were found in the watercourses. From these six trials it was concluded that stream and river buffers...