Treesearch

These guidelines were initially prepared as part of the FUEL-BREAK Program by Jay R. Bentley, Craig C. Chandler, and Verdie E. White, of the Pacific Southwest Forest and Range Experiment Station, from suggestions by field personnel. The guidelines were reviewed and revised by a committee as follows: Robert H. Blanford, Elmer Chambers, and Len Chatten of the California Division of Forestry; Harvey T. Anderson and R. M. Van Wagner of the Los Angeles County Fire Department; and Lynn R. Biddison and Lloyd R. Britton of the U.S. Forest Service. These guidelines will be subject to revision in 1963.

An average sawtimber stand having a dense understory was converted to one type of fuel-break for $132.00 an acre. Qualified observers believe this barrier would either stop or help in controlling a rolling fire under severe burning conditions.

Have you ever tried to use paint that had too much thinner? If you have, you know that it drips and runs. But paint that is “just right” stays in place. This property of a liquid that causes it to adhere to a solid surface--viscosity--is also valuable for materials used in coating the surface of fuels to retard and suppress wildfires. Viscous water and algin gel are two new materials designed to “stay put” on fuels. They have been tested extensively to determine their characteristics and their effectiveness on different types of fuels. They are only two of many chemicals being investigated...

Seed trees were selected in young-growth ponderosa pine to produce an estimated 25,000, 50,000, and 100,000 seeds per acre. A year after a good seed crop, ponderosa pine stocking in cutover plots was: 1,910, 4,020, and 4,820 seedlings per acre. Some additional regeneration of other species also occurred.

Three white pine hybrids exposed to infection by white pine blister rust (Cronartium ribicola Fischer) since 1946 have inherited the relative resistance of their parental species. The hybrids were produced from controlled pollinations in 1940 and 1941 at the Institute of Forest Genetics, Placerville, Calif. Twelve seedlings of each hybrid were planted in 1946 on a site near Rhododendron. Ore., where rust infection and growing conditions were severe. Concurrent tests at this locality showed the relative resistance of the parental species: Pinus monticola Dougl., very susceptible; P. strobus...

Tree growth, like all plant characters, is a product of the interaction of genes and environment; however, the genes, environment, and interaction are not the same for every individual of a species. Genes exert master control over the plant's growth mechanisms. They control mechanisms for responding to environment and for utilizing environment in growth. Usually many genes control growth, and their individual effects are thought to be additive. The contributions of the individual genes establish the genetically fixed range of tolerance of a tree. The environment supplies the raw material...

The job of watershed management research is to conduct studies which will suggest better methods of management for water and predict the effects of a wide span of land management practices upon streamflow, water yield, and sedimentation. A program for watershed management research was prepared by Henry Anderson in 1960 (Anderson, 1960).

Fuel-breaks in southern California are wide strips cleared of heavy brush to break extensive brushfields into manageable units. The breaks also provide open areas from which men can safely and effectively fight fires. Permanent revegetation of these cleared areas with a cover of light fuel is necessary to protect the soil. Perennial grasses are best for this purpose where they are adopted, but annuals such as ryegrass have a place on some areas. Commercial annual ryegrass (Lolium multiflorum), often seeded in the past on burned areas to provide temporary cover while brush is growing, does...

"We felt like witch doctors," was the complaint made by a foreman whose tanker crew had been selected to test the fire fighting qualities of "viscous water" (water containing a thickening agent). A few months later the same foreman, thoroughly familiar with the material, was convinced that under many conditions viscous water was superior to plain water in controlling forest fires. This change of opinion was the result of a three-part cooperative study conducted during the summer and fall of 1960 in California and Nevada. Use of chemical additives for water in forest fire control is not a...