I conducted a field study using gray wolf and mountain lion urine to investigate white-tailed deer and mesopredator behavioral responses to novel predator cues in a natural setting and to see if any changes in wildlife activity correspond to changes in the local biodiversity of a wetland environment. I created...
Remote sensing techniques have long been useful in quantifying changes in ecosystems and the field of remote sensing is constantly evolving to better assess and describe changes, both spatially and temporally. In this thesis I explored the novel use of two remote sensing methods to quantify ecosystems; repeat photograph to...
Reintroduction of wolves to Yellowstone National Park (YNP) in 1995-96 provided a rare opportunity to observe the response of an ecosystem to the return of a top predator, including possible reversal of decades of decline of aspen, cottonwood, and tall willows suppressed by intensive herbivory on elk winter ranges. To...
Quaking aspen (Populus tremuloides) is an important tree species in the western United States and there has been much concern about its persistence. In this thesis, I report on aspen in a portion of its range that has not been previously evaluated: the eastern and western slopes of the Central...
Gray Wolves (Canis lupus) were once found throughout North America including Oregon. Wolves were extirpated from Oregon due to heavy hunting pressure in the late 19th and early 20th centuries and have been absent for over 50 years. Successful reintroduction efforts in Idaho and the greater Yellowstone area have caused...
This study examined the differences, at various scales, between northern spotted owl (Strix occidentalis caurina) nest sites and non-nest sites, i.e., sites where no nests were found during surveys, in the Coast Ranges of Oregon. I compared land cover around 41 owl nest sites (ONS) and 41 non-nest sites (NNS)...
I used satellite remote sensing to examine the key factors controlling the natural revegetation of Mount St. Helens since its eruption in 1980. The study required three stages: determining the amount of vegetation present; characterizing vegetation change; and analyzing the influence of factors affecting vegetation change. To determine the amount...
Using historical maps and tools provided by GJS, the spatial patterns of
pre-logging forest conditions were quantified for three landscapes in western
Oregon. The spatial coincidence between forest patches and topographic
features was determined for slope gradient, aspect, elevation, and distance
from streams. Pre-logging and current forest compositions were compared....
Vertebrate diversity was modeled for the state of Oregon using a parametric approach to regression tree analysis. This exploratory data analysis effectively modeled
the non-linear relationships between vertebrate richness and phenology, terrain, and climate. Phenology was derived from time-series NOAA-AVHRR satellite imagery for
the year 1992 using two methods: principal...
Although it is well known that humans are strong modifiers of their environment, there is a need for greater understanding of human-wildlife interactions, both historically as well as currently. Historical journals can help shed light on early human-wildlife interactions, and the Lewis & Clark journals contain some of the earliest...
