Treesearch

A destructive whirlwind of tornadic force was formed in a 600-acre brush fire burning on the lee side of a ridge near Santa Barbara on March 7, 1964. The fire whirlwind, formed in a post-frontal unstable air mass, cut a mile long path, injured 4 people, destroyed 2 houses, a barn, and 4 automobiles, and wrecked a 100-tree avocado orchard.[higher-resolution image available at https://www.fs.usda.gov/psw/publications/documents/psw_rn061/psw_rn061_highres.pdf]

Top utilization practices in harvesting California timber have not changed appreciably between 1945 and 1964. Factors affecting top utilization are largely related to the condition of old-growth timber stands currently harvested, and they appear to be independent of ownership and geographical strata. Characteristic differences between species do occur, especially in the larger diameter classes.

Solid fluorescent particles suspended in a spray liquid are distributed in direct proportion to the size of the spray droplets. Use of solid fluorescent particles is the basis of a new method for visual recognition of the size and number of droplets impinging on target and nontarget portions of sprayed areas.

Of the nine introduced tree species planted in Unit 4 in 1960, one pine species has failed completely. A slash pine planting on pahoehoe lava shows good survival and growth. And a karri eucalyptus reached a height of 58 feet in 5 years. Competition from wild vegetation was the main cause of mortality.

Exposure of double-diffusion treated and untreated round posts of Hawaii-grown wood showed that (a) untreated 3- to 5-inch posts of 10 species will last from less than a year to 3 years, depending on species, and that (b) except for three species, the treatment did not afford a service life long enough to justify using it.

Written in Fortran IV and MAP, this computer program can handle up to 120 variables, and retain 40 principal components. It can perform simultaneous regression of up to 40 criterion variables upon the varimax rotated factor weight matrix. The columns and rows of all output matrices are labeled by six-character alphanumeric names. Data input can be from punch cards or BCD tape.

Three of the five years from 1959 to 1963 were drought years in the Bogard Ranier District in northeastern California. Precipitation records for 28 years from the Bogard area show that (a) drought conditions were present in one-third of the years; (b) drought occurred in about 54 percent of the falls and springs, 36 percent or the winters, and 50 percent or the summers; and (c) in 42 percent of the years at least two of the three main seasons (fall, winter, spring) were dry.

Santa Ana wind structure varies between the high main ridges, the foothills, and the canyon bottoms. In each of these regions, a typical pattern characterizes the Santa Ana. Strong steady wind, at the high levels are determined almost completely by the large scale weather patterns. lntermediate canyons and ridges are affected by Santa Ana winds only when the foehn is well developed. The low lee side foothills are affected only on the most intense days.

Asphalts and wax emulsions have been recommended as protective coatings to help obtain clean, safe burns in slash disposal work. Fuel value determinations in the laboratory indicate that such coatings add little to the fuel value of slash.

Widespread dieback of Purshia tridentata, on the Inyo National Forest in eastern California in the spring of 1964, was caused by a severe 3-day frost with daily minimums down to 13°F. An unusually warm 9-day period-with temperatures up to 70°F., which preceded the frost by a week, had induced the bitterbrush to break dormancy and start shoot elongation when the frost occurred. Damage to the bitterbrush caused reductions in the current range allotments. This is the first report of so severe a frost injury in this area.