Treesearch

For efficient control of tree hazard on recreation sites, a specific administrative goal must be selected. A safety standard designed to achieve the selected goal and a uniform hazard-rating procedure will then promote a consistent level of safety at an acceptable cost. Safety standards can be established with the aid of data for past years, and dollar evaluations are feasible. Cost optimization is possible but impractical with available data. The legal risk in adoption of safety standards is considered acceptable.

Damage to timber surrounding clearcuttings and in one light selection cutting in mixed white fir-red fir stands was monitored for 6 years in northeastern California. In some years, bark beetles apparently killed more trees than did wind damage, but in two of the study years, severe wind storms caused much damage. One storm produced mainly break-age, apparently influenced by snow load. The other, a hurricane, produced mainly wind-throw. Relation of damage to tree size, crown class, and relative location reveals some trends. Study of height of breaks suggests that a mechanical stress point...

Traffic load changes as a result of expansion of recreation facilities may be predicted through computations based on estimates of (a) drawing power of the recreation attracttions, overnight accommodations, and in- or out-terminals; (b) probable types of travel; (c) probable routes of travel; and (d) total number of cars in the recreation system. Once the basic model has been established, development alternatives may be simulated to provide percent change estimates of probable traffic load effects on each link of the road system. Illustrative estimates are made for six alternatives for the...

The relative effectiveness of 60-second films on fire prevention, with different narrators, was tested among high school students and by exposure on commercial television channels. The narrators were Smokey Bear, a Youth, and a Ranger. All three films were effective in teaching proper fire use practices to the high school classroom audience. In commercial TV showings, fire use practices were not learned, but the Youth film was more effective than the Smokey Bear film in making the sample population interviewed more concerned about fire law enforcement.

A series of computer programs is available to extract information from the individual Fire Reports (U.S. Forest Service Form 5100-29). The programs use a statistical technique to fit a continuous distribution to a set of sampled data. The goodness-of-fit program is applicable to data other than the fire history. Data summaries illustrate analysis of fire occurrence, detection and initial attack time, and space and time relationships of multiple fires.

An initial survey in 1964 measured the existing levels of knowledge and attitudes concerning use and abuse of fire in wildland areas among residents of Butte County, California. During the next 6 years, the California Division of Forestry carried out an intensive fire prevention program. A resurvey was conducted in 1970 to find out if any changes in levels of knowledge and attitude resulted. The evaluation showed little change during the interim. The number of fires in the study area dropped during the period of most intensive prevention activity. But the analysis was not conclusive in...

Advance reproduction of white fir and red fir released by cutting overmature over-story was studied at the Swain Mountain Experimental Forest in northern California, at 6,300 feet elevation. Seedling and sapling height growth before logging was only 0.1-0.2 foot per year. Five years after cutting, seedling and sapling height growth had accelerated to about 0.5 to 0.8 foot annually, with better trees growing 0.9-1.1 foot. Radial growth rate at ground level increased from 70 to 100 rings pet inch to 7 to 12 rings; some trees grew 2 to 4 rings. Damage to advance reproduction was caused by...

This report updates an earlier checklist, published in 1955, of vertebrate fauna found on the San Joaquin Experimental Range, in Madera County, California. Nineteen new species have been recorded since 1955. This report records the occurrences of seven fish, eight amphibians, 19 reptiles, 38 mammals, and 149 buds. References to research on individual species are included.

The boles of 32 recently killed, and 41 living, white fir were examined for embedded fir engraver (Scolytus ventralis) attack scars. Of 287 scars found in annual rings for the years 1934-69, only 2 to 3 percent represented reproductively successful attacks. Trends in scar abundance were directly correlated with trends in white fir killed by S. ventralis on 15 plots from 1939 to 1954. Influence of weather, host tree growth, and logging on yearly abundance of scars was examined by multivariate regression analysis. Years with increased scar abundance were preceded by at least 1 year of...

The visual impacts of alterations to the landscape can be studied by setting up Landscape Control Points–a network of permanently established observation sites. Such observations enable the forest manager to anticipate visual impacts of management decision, select from a choice of alternative solutions, cover an area for comprehensive viewing, and establish a method to integrate visual analysis with multiple-use planning. The visible landscape can be plotted by direct field observations, by laying out a series of sections as rays from a single LCP, or by a computerized mapping technique....