Treesearch

Root pressure exudates collected from detopped seedlings of Douglas-fir, grand fir, noble fir, Pacific silver fir, ponderosa pine, lodgepole pine, and Engelmann spruce were analyzed for sugars, amino acids, organic acids, nitrogen, potassium, calcium, and magnesium. Sugar concentrations ranged from 0.10 percent to 5 percent, and included glucose, sucrose, fructose, and two unknowns, possibly rhamnose, and ribose. Amino acid concentrations ranged from 0.02 to 0.10 percent, and organic acids from 0.01 to 0.06 percent. Aspartic acid, glutamic acid and glutamine were the main amino acids in...

The length of flames of wildland fires is a relative indicator of fireline intensity and an important index to fire effects and difficulty of control. A technique for measuring flame height and flame-tilt angle for the purpose of calculating flame length is described. Laboratory tests determined the feasibility of using cotton string treated with ammonium phosphate fertilizers to measure flame height. Ammonium phosphate treatments with an effective P2O5 equivalent greater than 10 percent by weight prevented the string from sustaining combustion above the zone of contact with flames....

Two populations of Douglas-fir trees were screened for graft compatibility. Two-stage testing procedures were used with either high- or low-intensity screening in the first step. Of 303 trees, 16 (5 percent) were found to be 90- to 100-percent graft compatible and suitable for seed orchard use as rootstocks. High-intensity screening in the first stage was more effective than the low-intensity screening in detecting highly compatible trees. Trees proven to be 90- to 100-percent compatible after second stage screening were propagated as rooted cuttings and used as parents in controlled...

The average biomass of big sagebrush (Artemisia tridentata Nutt.), antelope bitterbrush (Purshia tridentata (Pursh) DC.), snowbrush ceanothus (Ceanothus velutinus Dougl. ex Hook.), and greenleaf manzanita (Arctostaphylos patula Greene) was 6.1, 5.1, 10.7, and 16.2 tons per acre (13.9, 11.3, 24.0, and 36.0 tonnes per hectare), respectively, for 100-percent shrub crown coverage. Biomass by fuel size class and category is tabulated for percentage of crown cover.

Traps baited with Seudenol + a-pinene caught 87 percent more eastern larch beetles, Dendroctonus simplex LeConte, than did tamarack logs infested with females. Male beetles responded to the synthetic attractant in greater numbers than females. Male beetles were not attracted to frontalin, a principal attractant of the closely related Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins. Attraction was reduced by 92 and 86 percent by addition of methylcylohexenone (MCH) and frontalin but by only 36 percent when trans-verbenol was added. This evidence partially supports the taxonomic...

Nine herbicides were compared for aiding establishment of four conifer species on upper-slope forest sites dominated by sedge and beargrass. Both glyphosate and a mixture of atrazine + dalapon produced substantial and consistent gains in survival of all four conifers after 3 years.

Pupal density of western spruce budworm, Choristoneura occidentalis Freeman, can be accurately estimated from 45-cm branch tips. Density on tips was representative of densities on entire branches. Mean pupal densities on branch tips are statistically different from lower, mid, and upper crowns (p = .07). Therefore, multi-crown sampling is required to precisely estimate the mean of populations similar to those used in this study.

Ratios are presented for estimating the volume of logging residue for any location in Idaho, Washington, and Oregon. They show cubic-foot volume of logging residue per 1,000 board feet of timber harvested and per acre harvested. Tables show gross and net volumes, with and without bark. The volumes of live and dead and cull residue at the time of harvest are also given.

Information on the characteristics of logging residue in Idaho, Washington, and Oregon is presented. Tables show volume by diameter and length, number of pieces per acre, percent of residue that is sound, distribution by slope and distance to road, and average proportion of bark. Results are shown for 19 strata (harvest method by geographic area and owner).

To test their acceptance of foliage treated with herbicides, captive black-tailed deer were exposed to Douglas-fir seedlings and salal treated with standard formulations of 2,4,5-T, 2,4-D, atrazine, dalapon, fosamine, and glyphosate herbicides. Carriers were diesel oil and water. Tests were made from November 1977 through February 1978. Deer readily browsed 2,4,5-T treatments and most formulations of 2,4-D in oil compared with oil alone, but showed rejection of some phytotoxic glyphosate treatments. Consumption of herbicidetreated foliage did not cause noticeable health problems in test...