Buffer strips for stream temperature control

During clearcut logging, complete removal of the forest canopy and the shade it provides\ud to small streams can cause large increases in water temperature. Such increases in temperature can be prevented if buffer strips of vegetation are left along the stream to provide shade. The purposes of this paper are to define the characteristics of buffer strips that are important in regulating the temperature of small streams and to describe a method of designing buffer strips that will insure no change in stream temperature as a result of logging and, at the same time, minimize the amount of commercial timber left in the strip. Commercial timber volume alone is not an important criterion for temperature control. Further, the width of the buffer strip is also not an important criterion. For the small streams studied as part of this research, the maximum shading ability of the average buffer strip was reached within a width of 80 feet. Specifying standard 100- to 200-foot buffer strips for all streams generally will include more timber than necessary. The canopy density along the path of incoming solar radiation best describes the ability of the buffer strip to control stream temperature. An estimate of this value can be obtained easily by foresters laying out buffer strips in the field and will insure proper design of the buffer strip for control of stream temperature