Treesearch

Remote sensing techniques were investigated as an alternative for documenting selected prettack fire planning information. Locations of fuel models, road systems, and water sources were recorded by Landsat satellite imagery and aerial photography for a portion of the Six Rivers National Forest in northwestern California. The two fuel model groups used were from the 1978 National Fire Danger Rating System and the Northern Forest Fire Laboratory. Landsat-derived fuel model data were digitized and computer analyzed by unsuperivesed and guided clustering techniques to produce a fuel model map...

Young red firs (Abies magnifica A. Murr.) and white firs (A. concolor [Gord. & Glend.] Lindl. ex Hildebr.) on the Stanislaus National Forest, California, were inoculated with seeds of dwarf mistletoe (Arceuthobium abietinum) for 5 successive years. Only 3 to 4 percent of about 7000 seeds placed on branches resulted in infections. Second-generation infections developed and populations of the parasite built up on some trees but not on others after 17 years. Variables that appeared to regulate population increases included an 8- to 9-year average between inoculation and fruiting of plants,...

Monoterpene composition was studied in a number of hard pine species and results were compared with earlier work. (1) Intratree measurements showed strong constancy of composition in both single-stemmed and forked trees of ponderosa, Jeffrey, Coulter, and Jeffrey x ponderosa pines. In grafts of these and other pines, the scion influenced the root stock, but not the reverse. (2) Large intertree variation in composition was found in a small sample of seven hard pines native to Mexico; the value of monoterpenes in clarifying taxonomy of these pines remains uncertain. (3) An 80-tree plot of...

Some field studies of the effects of various insecticides on the spruce budworm (Choristoneura sp.) and their parasites have shown severe suppression of host (budworm) populations and increased parasitism after treatment. Computer simulation using hypothetical models of spruce budworm-parasite systems based on these field data revealed that (1) effective parasites produce greater stability in budworm populations than ineffective ones and are more resistant to changes induced by insecticides; and (2) the level of budworm population suppression in most budworm-parasite systems is not...

A sample of 231 independent timber investments were ranked by internal rate of return, present net worth per acre and the benefit cost ratio—the last two discounted by 3, 6.4. 7.5. and 10 percent—to determine if the different criteria had a practical influence on timber investment ranking. The samples in this study were drawn from a group of timber investments partially financed by Forestry Incentives Program costshare funds. The investment rankings were quite similar among the three criteria. Under constrained investment budgets, the benefit / cost criteria produced the investment...

In 1975-1976, pine trees killed by the southern pine beetle Dendroctonus frontalis Zimm.) in a 2l70-hectare (5362-acre) area at the William B. Umstead State Park in central North Carolina, were monitored by sequential color infrared aerial photography. From 1973 through summer 1975, beetles in 350 infestation spots killed more than 20,500 pines on 137 hectares (339 acres). From October 1975 to July 1976, an additional 301 dead pines were detected at 146 tree mortality centers. Southern pine beetles were associated with 98 percent of these dead trees. Pine mortality dropped rapidly from 248...

Two components of fire management programs were analyzed at these Forests: Francis Marion (South Carolina), Huron-Manistee (Michigan), San Bernardino (California), Tonto (Arizona), and Deschutes and Willamette (Oregon). Initial attack and aviation operations were evaluated by the criterion of minimizing the program cost plus the net value change of resource outputs and structures resulting from fire (C + NVC). Four alternative program or budget levels were investigated at each Forest for each of 3 years of varying fire severity. The program levels ranged from 20 percent below the 1979...

Techniques to calculate 1000-hour timelag fuel moistures were developed from theory of water movement in wood. The 1000-hour timelag fuel moisture is computed from mean daily temperatures and humidities and precipitation duration. Comparison of calculated and observed fuel moistures showed good agreement. Techniques to determine the seasonal starting value of the 1000-hour timelag fuel moisture are based on monthly climatological summaries. The seasonal starting value calculation was made from a least squares regression equation.

Before the telling of this tale could take place, there had to be an Experimental Forest and sorre events. Reasons for the establishment of the area will be covered later, but some of the records of establishment have been found. Blacks Mountain Experimental Forest, about 10,000 acres in size, was withdrawn from lands of Lassen National Forest and designated as an experimental forest by F. A. Silcox, (Chief) Forester, United States Forest Service, on March 28, 1934. This action fallowed a search by an Experiment Station committee for a suitable experimental area east of the Sierra Nevada...

Emergence of mamane (Sophora chrysophylla) was best when seeds were sanded or soaked in sulfuric acid and then sown at 3.8 or 6.4 cm. Soil moisture content and soil temperature were among the factors governing emergence from different sowing depths. End-of-test seedling survival was low-16 percent during a spring test and 2 percent during a summer test; it was significantly affected by type of seedcoat treatment, but not by sowing depth. Low rainfall and extreme soil surface temperatures appeared to account for most seedling mortality. In both tests, some seedlings which had died back to...