Treesearch

Consideration of the available data on cellulose pyrolysis suggests that, with relative importance depending upon heating rate in the temperature range 200-400°C, very pure cellulose decomposes by two competitive endothermic processes. lt is postulated that an unzipping reaction produces 1,4-anhydro-α-D-glucopyranose which rearranges to give levoglucosan. The other process, a dehydration, is considered to form the starting material for a subsequent exothermic process which results in CO2, CO, further H2O, and char. Although the known effects of some salts on cellulose pyrolysis can be...

Humidity patterns near the 500- to 1,000-meter level on California's coastal mountains often show an anomolous decrease in the moisture content at night and early morning. A study in the Santa Ana mountains suggests that nighttime downslope winds provide the most satisfactory explanation for the decrease in moisture because of their effect on the marine layer.

Young-growth, mixed-conifer stands were logged by a group-selection method designed to create openings 30, 60, and 90 feet in diameter. Total costs for felling, limbing, bucking, and skidding on these openings ranged from $7.04 to $7.99 per thousand board feet. Cost differences between openings were not statistically significant. Logging costs for group selection compared favorably with those previously reported for seed-tree and selection harvest cuts--$8.20 and $8.39, respectively.

Recording timber-cruise data with a portable tape recorder cost 10 percent less than using paper and pencil. Data errors of 1.3 percent were not considered important owing to the usual review.

Few areas in the world have so many introduced plants as the Hawaiian Islands. Government agencies, private organizations, and many individuals have engaged in sometimes major efforts to bring in useful species. lntroducing new species for forestry purposes began well before the turn of the century and is still continuing. Follow -up appraisal of the . adaptability of introduced trees forms an important part of forestry research. The Hawaii Forestry Division (and its predecessor agencies) has probably been the most active in tree introduction work. As early as 1887 Walker (1887) reported...

Flowering of koa was strongly seasonal on the Mauna Loa Strip. At 4,000 feet heavy flowering began in early December and lasted until early March. At 6,700 feet it extended from early March until mid-May. Heaviest flower losses occurred during anthesis, and were due to wind, rain, and possibly the dropping of unpollinated heads. Large insects were important as pollinators. Shoot growth was cyclic, being most rapid from April to August, and much slower from September to March, or April.

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.