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Effectiveness Of Grid Systems For Pheromone-Trapping Sparse Gypsy Moth Populations In Mountainous Terrain In The Intermountain West, Colleen Keyes

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Two field experiments determined an effective intertrap distance (ITD) for early detection and delimitation sparse gypsy moth (Lepidoptera: Lymantriidae, Lymantria dispar L.) populations in mountainous terrain. This study found that current Animal and Plant Health Inspection Service trapping guidelines are not sufficient for early detection of small gypsy moth populations in mountainous terrain. Detection trapping in mountainous terrain should have an ITD of not more than 804 m. Delimiting trapping should use a grid design with an ITD of 152 m.

A related study determined natural adult male mortality in the climate of the intermountain West, which includes Utah, Nevada, …

Bark Beetle Activity In Douglas-Fir, Pseudotsuga Menziesii Var. Glauca Mirb. (Franco), Following The 1994 Beaver Mountain Fire, Catherine A. Cunningham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The 1994 Beaver Mountain fire ignited the canopies of subalpine fir, Abies lasiocarpa, and spread ground fire into adjacent Douglas-fir forests, Pseudotsuga menziesii var. glauca. Despite shorter flight seasons due to lower annual temperatures and persistent snow, the Douglas-fir bark beetle, Dendroctonus pseudotsugae Hopkins, attacked a range of moderately fire-injured host conifers. Logistic regression models illustrated that in 1995 associated bark beetles selected large diameter Douglas-fir with 60-80% bole char, 60-80% crown volume scorch, and 50-70% probability of mortality due to fire. In 1996 beetle preference shifted to smaller diameter trees with lighter fire injury. Tree size was …

Delineation Of Ecological Units For The Ashley National Forest, At The Landscape Level, Using Classification Tree Modeling, Teresa H. Swiatek

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study integrated remotely sensed data, geographic information system (GIS), and classification tree-based modeling to delineate ecological units for the Ashley National Forest. Data points, provided by the Ashley National Forest, with a known location and dominant vegetation type, were related to data layers that were determined to be helpful in a landtype classification. These layers included elevation, slope, aspect, potential solar irradiation, precipitation, geology, basins, Landsat thematic mapper (TM) bands 3, 4, 5, and 6, and basic land cover. These points, with their related information, were then used to train the tree-based model for landtype classification. This resulted in …

Litter Decomposition And Nutrient Release Patterns In A Subalpine Forest In Northern Utah, Amber Denton Johnson

Undergraduate Honors Capstone Projects

In the arid subalpine zone of the intermountain west it is common to see patchy forests interspersed with open meadows containing scattered clusters of trees referred to as tree islands. These tree islands are often composed of subalpine fir [Abies lasiocarpa (Hook) Nutt.] and Englemann spruce [Picea englemannii (Parry)]. In desert ecosystems, where lack of water is the most important factor limiting growth and nutrient dynamics, it is not unusual to see individual plants (especially in the shrub community) creating "islands of fertility", in which the plants collect nutrients by pumping them from deeper in the soil profile and redepositing …