Treesearch

This compilation lists 117 bibliographic data bases maintained by scientists of the Forest Service, U.S. Department of Agriculture. For each data base, the following information is provided; name of the data base; originator; date started; coverage by subject; geographic area, and size of collection; base format; retrieval format; ways to query; who to query; and availability. Four indexes included: subject, originator, geographic coverage, and Forest Service and other locations.

This manual standardizes procedures for determining the moisture content of living chaparral for use in a proposed statewide system of monitoring living fuel moisture. The manual includes a comprehensive examination of fuel moisture variations in California chaparral, and describes techniques for sampling these variations. Equipment needed to sample and determine living fuel moisture is discussed. Detailed procedures for collecting living fuel samples and processing the samples for moisture content are provided.

The toxicities of acephate, aminocarb, carbaryl, chlorpyrifos, chlorpyrifos-methyl, methomyl, mexacarbate, permethrin, and trichlorfon to last instar wetern spruce budworm, Choristoneura occidentalis Freeman, were significantly altered by the presence of hostplant foliage. The pyrethroid permethrin was significantly more toxic when sprayed directly on fully exposed larvae than when first sprayed on foliage. However, all other toxicants were more toxic sprayed on foliage. A toxicologically-based method was used to assess the residual toxicities of the nine chemicals. Each chemical was...

The possible harmful effect of insecticides on nontarget organisms should be a prominent concern in all attempts to control forest pests. Although all wildlife must be considered, birds are particularly vulnerable. The study reported here was part of the effort to find an environmentally safe method to control one of the major sources of insect damage to forest trees - the Douglas-fir tussock moth (Orgyia pseudotsugata [McDunnough]). Its larval stage is an important defoliator of true firs (Abies sp.) and Douglas-fir (Pseudotsuga menziesii var. glauca [Beissn.] Franco)in western North...

Orthene was tested in a randomized block experiment to determine efficacy against larch casebearer. Needlemining larval populations were sprayed in September 1976 by helicopter with 0.5 lb Orthene/gal water/acre (560 g a.i/9.3 l/ha). Spray deposit was sampled with Kromekote cards. Plot mean larval populations, spray deposit, and defoliation index were analyzed to detect significant differences among treatments by using twoway analyses of variance. Larval populations were reduced an average of 92.1 percent on the nine treated plots and an average of 40.5 percent on the three check plots....

In stands of mixed white and red fir in northeastern California, cuttings for natural regeneration became well stocked with seedlings within 2 to 5 years after cutting. Seed tree and shelterwood cuttings, clearcut strips not more than 3 chains (60 m) wide, and patches not exceeding 4 chains (80 m) width were studied. Incidence of damage among residual trees in or adjacent to cuttings was negligible. Low vegetation developed slowly and did not appear to affect seedling survival.

Growth was analyzed after one thinning in a plantation of pole-size ponderosa and Jeffrey pines on land having a site index of 50 feet at 50 years. Periodic annual increment was determined for each of three 5-year periods. On this basis, increment in diameter and cubic volume were found to he related closely to stand basal area only. Basal area and height increment, however, were also related to time since thinning: basal area growth decreased and height growth increased with each succeeding period. The optimum basal area for volume production (both cubic and board-foot measures) was...

Snow is a major source of water in Western United States. Data on snow depth and average snowpack density are used in mathematical models to predict water supply. In California, about 75 percent of the snow survey sites above 2750-meter elevation now used to collect data are in statutory wilderness areas. There is need for a method of estimating the water content of a snowpack in inaccessible locations by remote means. If snow albedo can be measured from aircraft and these measures correlated with snowpack density, we should be able to estimate density remotely. But a correlation must...

Release cutting, live crown ratio, diameter-at-breast height, and dwarf mistletoe (Arceuthobium abietinum f. sp. magnificae). acted to affect radial and height growth of red firs (Abies magnifica A. Murr.). Infected and noninfected red firs responded well to release as expressed by increased radial growth: growth rate doubled within 10 years after release. Live crown ratio also had a marked effect on radial growth rate. Irrespective of the level of dwarf mistletoe, trees with good live crown ratios showed significantly greater rates of radial growth than did trees with poor live crown...