Energy expenditures, perceived family well being, and energy
conservation actions were analyzed by family composition and level of
income. Data were from a three state subsample (Arizona, Colorado,
and Oregon; N = 2,633) of a larger stratified random sample of
households in the Western United States. Data were collected in...
Multiple successional sequences have been observed following disturbance in communities on marine hard substrata. Observations of the turf-forming alga, Iridaea cornucopiae Post. & Rupr. (Gigartinaceae), suggest that I. cornucopiae may assume its dominance by its ability to vegetatively pre-empt space. High limpet densities in the natural community, suggest that I....
The stability of a limpet-dominated community was
assessed in a experiment in which an consumer was
temporarily removed. Compared to unmanipulated plots,
the limpet-exclusion plots developed greater algal
abundance and altered species composition of both algae
and barnacles. The community was not perturbed beyond
its capacity to recover, since the...
Data in the form of counts or proportions often exhibit more
variability than that predicted by a Poisson or binomial
distribution. Many different models have been proposed to account
for extra-Poisson or extra-binomial variation. A simple model
includes a single heterogeneity factor (dispersion parameter) in the
variance. Other models that...
I studied bird and rodent nesting in woodpecker-excavated
cavities in pifion-juniper (Pinus edulis-Juniperus monosperma) (P-J)
woodland in southeastern Colorado during the spring and summer of 1987
and 1988. Two related investigations were conducted: one described
characteristics of habitat used by birds and rodents nesting in
woodpecker-excavated cavities and the other...
The study presents the results of a descriptive analysis of the skeletal remains of 66
individuals recovered from the Fuller and Fanning Mound sites, located on the Yamhill River,
Willamette Valley, Oregon, excavated in 1941-42 by W. T. Edmundson and William S.
Laughlin. The literature and original field notes have...
Marbled Murrelets (Brachyramphus marmoratus) are threatened seabirds that are prone to disturbance both at sea and at old-growth forest nesting areas. I examined murrelet behavior and activity patterns in forest and marine ecosystems of Oregon. Diving behavior was studied during the 1995 and 1996 breeding seasons and was compared to...
The western North Atlantic population of the northern right whale (Eubalaena
glacialis) was severely depleted by whaling over the last century. Despite over fifty
years of protection, fewer than four hundred individuals are believed to exist in the
North Atlantic. Relatively little is known about the diving behavior, respiratory
physiology,...
Assessment of the environmental impacts of an agricultural production system
requires information on both soil water quality and solute flux. Passive Capillary Samplers
(PCAPS), which sample water from the vadose zone using fiber glass wicks, have shown
potential to provide both flux and solute concentration in unsaturated zone sampling but...
In order to examine the potential impact of military jet overflights and other disturbances on productivity of peregrine falcons (Falco peregrinus), we observed behavioral reactions of peregrines to disturbances at nests along the Tanana River, Alaska during the 1995-1997 breeding seasons. Military jets conducted low-altitude flights over a sample of...
The relationship between nutrients and community structure is poorly understood in open-coast habitats. I created a system of artificial tidepools, of identical age and physical dimensions, at two sites that differed in wave exposure, and manipulated nutrient levels and the abundance of herbivores. Using these unique field mesocosms, I explored...
This dissertation considers two approaches for testing hypotheses in
unbalanced mixed linear models. The first approach is to construct a design with
some type of structure or "partial" balance, so that some of the optimal properties of
a completely balanced design hold. It is shown that for a particular type...
Environmental monitoring poses two challenges to statistical analysis: complex data and complex survey designs. Monitoring for system health involves measuring physical, chemical, and biological properties that have complex relations. Exploring these relations is an integral part of understanding how systems are changing under stress. How does one explore high dimensional...
Spring chinook salmon, Oncorhynchus tshawytscha, in the Snake River Basin are listed as endangered under the Endangered Species Act. The typical life history of spring chinook salmon is semelparous. An experiment was performed to see if mature male spring chinook salmon parr could be reconditioned after hand-spawning and spawned in...
Ecologists have long questioned why fluctuating populations tend to persist rather than go extinct. Populations that persist indefinitely are regulated by mechanisms that cause demographic density dependence, which works to bound fluctuation above zero. In a series of studies, I have sought to determine the processes and mechanisms that regulate...
Despite their inherent importance and utility as ecological examples, island species are among the most endangered and least studied groups. Guam Micronesian Kingfishers (Halcyon cinnamomina cinnamomina) exemplify the plight of insular biota as a critically endangered and understudied island bird that went extinct in the wild before they could be...
The Van Dyke's salamander (Plethodon vandyke,) is a rare species endemic to Washington State. It has been found in cool moist microhabitats along streams, splash zones of waterfalls, and headwater seeps. We explored the association of the Van Dyke's salamander with hydrologic condition, geomorphology, disturbance characteristics, and vegetation structure in...
Understanding how large-scale processes (>100 kms) influence ecological communities is currently a major focus in ecology. In marine systems, coastal upwelling, a large-scale oceanographic process in which surface water pushed offshore by winds is replaced by cold, nutrient-rich water from depth, appears to cause variation in rocky intertidal communities. Along...
An understanding of the tectonic history of the Klamath Mountains
is crucial for a valid paleogeographic reconstruction of the Pacific
Northwest. However, prior to this study there were very few
paleomagnetic (PM) data from the Klamath Mountains (KN), which resulted
in conflicting interpretations about the role of the KM province...
Population genetic structure is widespread in many organisms and can be found at small spatial scales. Fine-scale differentiation is the result of ecological and evolutionary processes working together to produce an overall pattern, but the relative importance of these factors in population differentiation is poorly understood. The goals of my...
The physical characteristics of continental shelf waters off
Oregon during late winter and spring of 1975 are described and compared
with observations taken previously during summer. The currents
in winter are barotropic in the monthly means while in summer
the currents are baroclinic. Alongshore current fluctuations on the
time scale...
Pelargonidin 3-glucoside (pgd 3-glu), pelargonidin 3-sophoroside (pgd 3-soph),
and pelargonidin 3-sophoroside 5-glucoside acylated with cinnamic and malonic acids
(acyl-pgd 3-soph 5-glu) were extracted from strawberries (Fragaria anannassa cv,
Totem), nasturtium flowers (Tropaeolum majus), and radish peel (Raphanus sativus L.
cv, fuego), respectively. Their stability was studied in natural and model...
Biochemical properties, functional properties, and market potential of Pacific whiting (PW) fish sauce were investigated. Biochemical properties of fish sauce made from whole fish (W) and a mixture (1:1) of whole fish and surimi byproducts (WB) were compared. Market potential was evaluated through phone interviews and consumer panelists. Proteolysis was...
Raw product value of vegetables for processing in the
Northwest used to be established by a competitive market
involving proprietary processors and growers. Due to the
relocation of proprietary processors to the Midwest, this
competitive market has eroded forcing cooperative processors
to seek other means to set raw product values....
The ecology of the North Atlantic right whale (Eubalaena glacialis) was examined at three spatial scales during the summer and early fall on their northern feeding grounds. The diving and foraging behavior of right whales was investigated at spatial scales of hundreds to thousands of meters by tagging right whales...
Mesoscale surveys to examine the relationship between the physical processes and biological response along the Antarctic Polar Front (PF) were conducted as part of the US JGOFS Southern Ocean Program during austral spring and summer 1997/98. Multiple crossings of the PF near 170° W, using a towed undulating instrument, provided...
The United States invests tens of billions of dollars in higher
education each year. This had led many researchers to estimate the
marginal and average rates of return to these expenditures. Past
works, however, have been partial in scope. That is, they have
counted only the benefits of higher education...
Environmental and regulatory concerns are causing confined animal feeding operations (CAFO's) to account for phosphorous content when applying wastewater to agricultural fields for disposal. In most cases this requires more land to spread the waste onto so that the phosphorous needs of the crop are not exceeded. A mobile process...
The Tillamook and Kilchis subbasins of the Tillamook Bay watershed (Oregon Coast Range) have differences in geology and land use history and, therefore, varied environmental conditions that could affect fish assemblages. Fifty-two randomly selected wadeable stream reaches in these two subbasins were surveyed for stream habitat and fish assemblage composition...
I investigated Caspian terns (Sterna caspia) breeding at colonies on the Columbia Plateau (southeastern Washington and northeastern Oregon), with emphasis on the breeding and foraging ecology of Caspian terns nesting at colonies in the mid-Columbia River. I focused research at colonies where Caspian terns foraged on juvenile salmonids (Oncorhynchus spp.)...
Little is known about Columbian black-tailed deer (Odocoileus hemionus columbianus) because of their elusive nature and the logistical difficulty of studying them in densely forested and mountainous terrain. The Oregon Department of Fish and Wildlife has identified fawn survival as an important gap in the current knowledge of demography and...
Landscape level habitat alterations can have different effects on different species. Species that are more highly specialized for some important aspect of their natural history are expected to be more sensitive to habitat alteration than are those that are generalists. The Northern Pygmy-Owl (Glaucidium gnoma) has been suggested as a...
Seven species of water-dependent birds (northern phalarope,
Phalaropus lobatus; American avocet, Recurvirostra americana; Wilson's
phalarope, P. tricolor; eared grebe, Podiceps nigricollis;
ring-billed gull Larus delawarensis; California gull, L.
californicus; and northern shoveler, Anas clypeata) were studied
during the fall migrations of 1982 and 1983 to determine the diets and
foraging...
As concern over global warming intensifies, sequestration and storage of atmospheric CO2 has become an important scientific and policy issue. Confusion persists, however, over interpretation of forest carbon (C) source-sink dynamics, in part because conclusions drawn depend on temporal and spatial scales of analysis (e.g. day-week
scale vs. successional-scale), type...
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...
Disaggregative and individual-tree/distance-independent modeling methods are
compared and contrasted. Differences between the two are related to differences in functional
and apparent resolution and may be illustrated using aggregation theory. When considering
models of different levels of resolution describing a given phenomenon, invariance with respect
to the aggregation implied (symmetry) may...
Since their range expansion into the Pacific Northwest, anecdotal evidence suggests that northern barred owls (Strix varia varia) may be displacing northern spotted owls (Strix occidentalis caurina). My objectives were to characterize barred owl distribution and population increase in Oregon, investigate spotted owl territory performance before and after barred owl...
Breeding ecology and behavior were investigated in a field study of three sympatric anuran amphibians in the Oregon Cascade Mountains: the western toad (Bufo
boreas), the Cascades frog (Rana cascadae) and the Pacific treefrog (Hyla regilla). A comprehensive study of the western toad mating system was conducted at three populations...