Mortality from various causes was recorded in a Douglas-fir tussock moth, Orgyia pseudotsugata McD., outbreak southeast of Coeur d'Alene, Idaho, in 1974. Observations began June 27 when about 50 percent of the larvae were second instars and continued until pupation. Within a 35-day period, there was a 93 percent average...
The pine needle cast fungus, Lophodermella concolor, caused severe discoloration and subsequent defoliation of lodgepole pine on over 4,000 acres and light defoliation on over 4,500 acres of lodgepole pine in the lower Clark Fork River drainage in 1975. Some trees had lost the last 3 years' growth of needles,...
Aerial surveys of six Montana National Forests in 1975 found a 22.1% increase in the area of visible defoliation caused by the western spruce budworm. It is estimated that 2,278,804 acres of Douglas-fir forests are now suffering at least 25% defoliation. This is an increase of 503,706 acres over the...
Average annual losses caused by geologic hazards in Oregon are difficult to determine, owing to incomplete and scattered data. Preliminary considerations, however, indicate that losses to landslides may total between $4 million and $40 million per year. As many as nine persons have been killed by one landslide in Oregon...
The geology of Oregon has become a jigsaw puzzle of moving parts set on a foundation of changing conditions as the crust and mantle undergo successively different manners of deformation through time. As more megahypotheses arise from increasingly sophisticated views of plate tectonics and from more detailed analyses of synoptic...
The Columbia River Basalt consists of dozens of seemingly identical flows of basalt covering thousands of square miles of Oregon, Washington, and Idaho. For years, detailed mapping of the units relied almost entirely on subtle petrographic distinctions, the presence or absence of interbeds, and actual walking along contacts in the...
The following outline of events in the rise and fall of gold mining in southwestern
Oregon is here recorded - almost as an obituary - so that Oregonians may not entirely forget how important this industry was in building up this part of the state.
Dipel (R) was applied by helicopter to three blocks of Douglas fir and Engelmann spruce infested with Choristoneura occidentalis Free., in southwestern Montana. Dosage was 1 pound (7.2 Bill) in 2 gallons of water/acre (453 g in 7.5 t/0.4 ha). A commercial surfactant, Bio-film (R) was added at the rate...
Baseline data for the first year of a two-year study to assess
the current status of ponderosa pine stands in southeastern
Montana relative to coal-fired electric power development are
presented. Sixteen permanent plots in pine stands were established
in eastern Montana, South Dakota, and Wyoming. Several characteristics
believed to be...
Windthrow occurred during late April on the Glacier View, Hungry Horse, Spotted Bear, and Swan Lake Ranger Districts, Flathead National Forest. An evaluation to determine potential for development of spruce beetle and Douglas-fir beetle outbreaks was made during late June and early July. All areas examined were classed as having...
The lodgepole pine type commonly occurs as an even-aged, singlestoried, and overstocked forest. Dwarf mistletoe is widespread throughout the type and causes growth and quality reduction, reduced seed production, and some direct mortality. The land manager has three alternatives where dwarf mistletoe occurs: (1) do nothing, (2) eradicate the stand,...