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Concerns are often voiced about possible environmental damage as the result of the cumulative sedimentation effects of logging and forest road construction. In response to these concerns, National Forests are developing procedures to reduce the possibility that their activities may lead to unacceptable cumulative effects

Abstract - The California Department of Forestry and U.S. Forest Service, Pacific Southwest Forest and Range Experiment Station have been conducting a paired watershed study on Jackson Demonstration State Forest for 24 years. The South Fork watershed phase of the study involved monitoring the impacts of road construction (1967) and selective tractor logging (1971-1973) on water and sediment discharge. The present North Fork phase of the study uses an extensive network of flumes with pumping samplers to monitor the impacts of clearcutting a portion of the North Fork utilizing upper slope...

Abstract - Debris slides over a 20-year period were inventoried on 137,500 acres of forested land in the Klamath Mountains of southwest Oregon. Frequency during the study period was about one slide every 4.3 years on each 1,000 acres-an erosion rate of about 1/2 yd 3 per acre per year Erosion rates on roads and landings were 100 times those on undisturbed areas, while erosion on harvested areas was seven times that of undisturbed areas. Three-quarters of the slides were found on slopes steeper than 70 percent and half were on the lower third of slopes. The study area was subdivided into...

A programmable calculator connected to an interface circuit can control automatic samplers and record streamflow data. The circuit converts a voltage representing water stage to a digital signal. The sampling program logs streamflow data when there is a predefined deviation from a linear trend in the water elevation. The calculator estimates suspended sediment discharge from rating coefficients for the gauging site. When a threshold value of accumulated suspecded sediment discharge is reached, the calculator sends a signal to the interface circuit that activates a pumping sampler. The...

Updating the National Fire-Danger Rating System (NFDRS) was completed in 1977, and operational use of it was begun the next year. The System provides a guide to wildfire control and suppression by its indexes that measure the relative potential of initiating fires. Such fires do not behave erratically–they spread without spotting through continuous ground fuels. Estimates of fire potential have a basis in the mathematical models used for fire behavior. The fire manager must select the fuel model that best represents the fuels in the protection area. Among the 20 fuel models available, not...

This state-of-knowledge report summarizes the best available information on maintenance, restoration, and management of meadows of the Sierra Nevada, California. Major topics discussed include how to classify meadows, meadow soils, productivity of meadows, management problems, and how to evaluate range conditions and trends. Current methods and standards are reviewed, and revised standards for evaluating conditions and trends are suggested. A primary conclusion is that proper meadow management requiresproper range management, including the watershed above meadows and control of user...

The following is a report on the status of Candidate Old-growth (hereafter identified as COG) on National Forest System administered lands in California in the past, a t present, and in the immediate fhture. These r e s u l t s are based on information that may be speculative and contain inconsistencies, and therefore must be treated with caution. COG on these lands has declined substantially since 1900 or about the time the National Forest System was established. Estimated declines are from about 4 million acres in 1900 t o about 2 million acres a t present--a decline of about 50 percent.