Forest Sciences Commons^™

Lodgepole Pine Susceptibility Rating Of Mountain Pine Beetle Through The Use Of A Density Management Diagram, John Albert Anhold

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ninety-four unmanaged lodgepole pine stands were examined to evaluate the relationship between stand density and susceptibility to mountain pine beetle attack. Sample included stands from a broad geographical range in the western United States.

Beetle population trends were not significantly related to variation in stand density as measured by stand density index (SDI). The percentage of trees killed per acre by the mountain pine beetle in stands with greater than eighty percent lodgepole pine did vary significantly with changes in SDI. From these data three SDI zones were identified: 1) stands with SDI's of less than 125 showed low potential …

Investigation Of Host Selection By Mountain Pine Beetle (Dendroctonus Ponderosae) Hopk. In Lodgepole Pine (Pinus Contorta) Dougl., Thomas James Eager

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lodgepole pines Pinus contorta (Douglas) were treated by girdling to assess the response by an endemic population of mountain pine beetle Dendroctonus ponderosae (Hopkins) (Coleoptera: Scolytidae). Capture in 'sticky traps' indicated that the beetles were attracted while in flight towards the wounded trees. A significant difference in the landing rates of bark beetles between the treated and untreated trees indicated that the beetles were able to distinguish wounded from non-wounded trees while still in flight. Pressure chamber readings demonstrated that water stress developed in the girded trees when compared to the non-girdled trees.

Impact Of The Western Spruce Budworm On Buds, Developing Cones And Seeds Of Douglas-Fir In The Intermountain Region, Charles Joseph Frank

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The western spruce budworm, Choristoneura occidentalis Freeman (Lepidoptera: Tortricidae), is a serious defoliator of conifers in the western U.S. and western Canada. In 1985 epidemic levels of the budworm caused average tree defoliation in west-central Idaho to increase to 83%, up substantially from the 35% average tree defoliation of 1984. Associated with this increase in defoliation was a change in the relative stand defolation ranking between the two years. found to damage all types and In 1985 the budworm was developmental stages of reproductive structures of Douglas- fir, including: seedcone buds, pollen-cones buds, maturing cones, and seeds. Differential selection of …

The Effects Of Recreation Specialization And Motivations On The Environmental Setting Preferences Of Backcountry Hikers, Randy J. Virden

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study explored how recreation specialization and different types of motivations were related to environmental settings preferred by backcountry hikers. A questionnaire was developed that measured the level of hiking specialization, desired psychological outcomes, and preferred environmental setting attributes. Questionnaires were mailed to 619 backcountry hikers from three Intermountain West hiking areas; a response rate of 68 percent was attained.

Results of the study revealed significant associations between the level of hiking specialization and the psychological states desired by backcountry hikers. In general, increased hiking specialization served to increase the importance of specific psychological outcomes such as autonomy, exercise, achievement …