Natural selection, in its most basic form, is described as a process in which traitsincrease or decrease in frequency depending on their fitness, and only the trait withthe highest fitness will remain in the population. Yet, populations rarely have asingle `optimal' trait. The way natural selection maintains this observed variationwithin...
Three studies were conducted to characterize and present early-seral
competition between Douglas-fir seedlings and the surrounding vegetation
communities during Pacific Northwest forest establishment. The first experiment
served as the foundation for this dissertation and was designed to quantify tradeoffs
associated with delaying forest establishment activities by introducing a fallow year...
A series of experiments were established to gain a better understanding of the extent to which Douglas-fir seeding root architecture may be manipulated and subsequent influences on seedling morphological and physiological development. The incorporation of amendments into nursery soils changed root architecture to some degree, but did not produce large...
Weed control in Pacific Northwest forests has been criticized for its potential impact on biodiversity. Changes were evaluated in conifer growth, diversity of vegetation in situ and of recruiting plants through different regeneration mechanisms after applying temporally-varied weed control by herbicide treatments based on the critical period concept. Conifer size...
In this thesis we construct compatible discretizations of Maxwell's equations. We use the term compatible to describe numerical methods for Maxwell's equations which obey many properties of vector Calculus in a discrete setting. Compatible discretizations preserve the exterior Calculus ensuring that the divergence of the curl and the curl of...
The three essays in this dissertation progressively answer the following questions: (a) How important are constraints? (b) Who benefits from removing constraints? (c) When does a constraint for a single market predominantly affect closely related markets? These questions are applied in the context of time, weather, and minimum wage constraints,...
The problem of locating a signal source, or an emitter, has many civilian and military applications, such as communication regulations enforcement, military reconnaissance, and search-and-rescue operations. Many of the most widely used emitter location methods rely on the accurate and robust estimation of the differential time delay,
or time-difference-of-arrival (TDOA),...
When the nonconformities are independent, a multivariate control chart for nonconformities called a demerit control chart using a distribution approximation technique called an Edgeworth Expansion, is proposed. For a demerit control chart, an exact control limit can be obtained in special cases, but not in general. A proposed demerit control...
Learning Analytics and other branches of Educational Research such as Computing Education Research (CER) implicitly assume that students, especially college students, have no barriers to access learning platforms or software packages. This assumption may be attributed to such pervasive beliefs such as "everyone has a device", or "everyone can access...
Most reserves fail to capture the habitat heterogeneity necessary to maintain viable populations of wide-ranging species. Methods to determine defensible dimensions of reserves and reserve networks are needed. The primary goal of this study was to develop such methods for lowland tropical forests by examining habitat- and spatial-use patterns of...
