Graduation date: 1996

The purpose of this study was to document vegetation on "The Island", a Research Natural Area at the confluence of the Crooked River and the Deschutes River in central Oregon's Juniperus occidentalis Zone and to compare the results with an earlier study reported in 1964 from 1960-'61 data. Present-day comparisons were also made between "The Island" vegetation and three nearby sites. Percent cover and constancy of major tree, shrub, grass, and forb species were considered along with percent cover of litter, moss/lichen, rock and bare ground. Climatic data from the Metolius, OR Station were examined, and the literature of succession especially succession in the juniper and sagebrush steppe of the Great Basin was reviewed. Data from 1992-'93 show more woody vegetation on "The Island", both tree and shrub, than was measured thirty years ago. The only tree species present is Juniperus occidentalis, while major shrub species are Artemisia tridentata and Purshia tridentata. Grass cover appeared to be less, with a more even mix of the native perennial bunchgrass species Agropyron spicatum, Festuca idahoensis, Poa sandbergii, and Stipa thurberiana, than in the past when Agropyron spicatum and the alien annual grass, Bromus tectorum dominated. The two plant associations identified in the 1964 report by Driscoll, Juniperus occidentalis / Artemisia tridentata / Agropyron spicatum and Juniperus occidentalis / Purshia tridentata / Agropyron spicatum were still identifiable, but the shrub, Artemisia tridentata appeared to be entering areas where Purshia tridentata had dominated in the past study. The present-day comparison sites showed many similarities with sites on "The Island." The comparison sites in the Juniperus occidentalis / Artemisia tridentata / Agropyron spicatum association measured slightly more tree and shrub cover but similar grass cover when compared to "The Island." The comparison site in the Juniperus occidentalis / Purshia tridentata / Agropyron spicatum association had more tree cover and more Purshia tridentata cover, but less shrub cover generally and more grass cover than the same association on "The Island." Forbs represented less than one percent cover on all study sites. The differences recorded in 1992-'93 from that of the study thirty years ago may reflect successional processes at work and a lack of any major natural fires in the system. / Graduation date: 1996

Transitional areas between upland and aquatic habitats, commonly known as wetland, were once viewed as unproductive areas and were drained for farming or pasture. Wetlands are now accepted as significant ecological resources, and their protection is a mandate of federal, state, and local land managers. Due to the diversity of wetland areas, the appropriate assessment of wetland resources cannot be accomplished without long term monitoring of wetland functions. Knowledge of the duration of saturation and associated anaerobic conditions of soils in wetlands is critical to correctly classify and assess wetland areas. Soil, hydrological, and biogeochemical characteristics of the soils of the Jackson-Frazier wetland were observed from October 1992 through March 1994. Weekly observations of water levels and redox potential at depths of 25, 50, and 100 cm were made in order to characterize the degree and duration of saturation and the anaerobic conditions in the soil over time. Permanently installed piezometers measured free water in the soil and indicated the presence of two separated water tables from the onset of the rainy season in October until February when the entire soil profile became saturated with free water. Platinum electrodes measured redox potential in the soil and indicated anaerobic conditions for ten months during the first season of observation and through March of the second season. Anaerobic conditions were considered to be achieved when Fe����� was reduced to Fe����� at a potential of 200 millivolts. The highly reducing conditions correspond to periods of soil saturation indicated by piezometers. Concentrations of iron and manganese observed in soil profiles correspond to conditions of prolonged saturation and reduction confirmed by monitoring. A soil stratigraphic study done with auger holes revealed a recent alluvial deposit of montmorrillonitic clay overlying lacustrine silts identified as the Irish Bend Member of the Willamette Formation. The clay deposit overlying the surface of the wetland acts as an aquitard and creates extensive surface ponding, which maintains the saturated habitat required for wetland vegetation. The subsurface hydrology is controlled by water flowing through the Irish Bend silts which results in saturation of the soils from below. Biogeochemical transformations of iron and manganese due to suboxic and anaerobic conditions are controlled by this type of soil saturation in the Jackson-Frazier wetland. / Graduation date: 1995

Graduation date: 1953

Graduation date: 1995

Several archaeological examinations have taken place at site 35CS43 in the modern town of Bandon, on Oregon's southern coast. The site has proven to be complex, including evidence of past use as both a cemetery and living site with specialized areas for the harvest and processing of estuarine resources. The site includes huge quantities of shell found in concentrated refuse heaps or middens. Samples of this shell have been taken over the course of excavations and stored for later consideration and analysis, the results of which should lend to greater theory concerning aboriginal subsistence and culture of the occupants of the lower Coquille river estuary. In this analysis of shell material from 35CS43, several previous shell analyses on the Oregon coast are summarized. A shell sample drawn in 1990 is then quantified and analyzed. Finally, information presented is formulated into a model for future excavations and shell analyses. To understand the shore it is not enough to catalogue its life. Understanding comes only when, standing on a beach, we can sense the long rhythms of earth and sea that sculpted its land forms and produced the rock and sand of which it is composed; when we can sense with the eye and ear of the mind the surge of life beating always at its shore blindly pick up an empty shell and say 'This is a murex.' or 'That is an angel wing.'. True understanding demands intuitive comprehension of the whole life of the creature that once inhabited this empty shell: how it survived amid surf and storms, what were its enemies; how it found food and reproduced its kind, what were its relations to the particular sea world in which it lived. / Graduation date: 1994

There are two major problems associated with soil acidity and lime response investigations: A. Determining how much lime (100% "available" CaCO��� equivalent) is required to raise a soil pH (or degree of acidity) from its existing level to a specified level - presumably where need for lime is eliminated. B. Determining responses of different crops on different soils to lime; and defining some chemical measurement of the soil that will predict the response of a specified crop. Investigations in this study were limited to the first problem. Liming characteristics of 45 acid Willamette Valley soils, representing the major agricultural soil associations, were determined by incubating the soils with increments of CaCO���. The lime required to bring the soils to the specified pH levels of 6.8, 6.4 and 6.0 varied widely within the respective pH levels. Relationships between soils, however, as determined by the value of the incubation curve slope (meq. of CaCO��� /100g of soil required to raise soil pH by one unit), were improved by grouping into related soils. Laboratory measurements of other soil chemistry parameters were compared with changes in pH to determine if a satisfactory quick laboratory procedure could be developed to measure the incubation lime requirement of soils with different chemical characteristics. Measurements of soil pH were made by three different methods: (1) in the supernatant of a 1:2 soil to water suspension; (2) in the sedimented paste of the 1:2 soil to water suspension; and (3) in the supernatant of a 1:2 soil to 1 N KCl suspension. Lime requirement with a buffered solution was measured in limed and unlimed soils by use of the SMP (Shoemaker, McLean, and Pratt) buffer method. Soil samples treated with increments of lime were analyzed for extractable Al and exchange acidity by titration and the unincubated soils were analyzed for exchange acidity determined by subtracting exchangeable bases from CEC measured at pH 7. 0 and pH 6. 0. Results of the correlation analyses showed that the SMP buffer method should prove useful for predicting the incubation lime requirement. Correlation coefficients for these two values were .89, .90 and 86, respectively, to reach pH levels of 6.8, 6.4 and 6.0. Soil pH measurements, extractable Al, and exchange acidity determinations did not provide as good a basis for determining incubation lime requirements, Regression equations were calculated for the SMP buffer/incubation lime requirement relationships. The purpose of this study was to identify the changes in soil chemical measurements that take place with application of lime. No attempt was made to determine whether a crop might respond to an application of lime on an acid soil. The assumption was made that yield could be related to specific pH or soil acidity levels that could be measured in the laboratory. Therefore, the problem was approached by studying procedures that might determine the application of lime required to reach a specified pH or soil acidity measurement. It anticipated that field trials for evaluating lime response will be carried out in the future to evaluate the usefulness of the SMP buffer method which showed promise in this regard. / Graduation date: 1972

The ex-vessel coho salmon market has been paid scant attention in the study of the salmon resources. This study is an attempt to advance an understanding of the variations of ex-vessel prices and landings during the coho season as well as between the various coastal ports where the fish is landed. This study presents an empirical analysis of the ex-vessel port markets for coho salmon in Oregon and Washington. The objectives of the study are to investigate the variation in landings and prices during the fishing season and to compare those differences between ports for both states. This study focuses on the determination of the ex-vessel price mechanism and the decision behavior of coho fishermen in their choice of ports to land the catch. An economic model of each port is developed to explain the buying behavior of processors and the selling behavior of fishermen. Each port is treated as a distinctive market subject to external changes in the abundance of coho, the conditions of the wholesale markets, and the responsiveness of fishermen to prices in other ports. Several econometric models are constructed to determine the distinctive characteristics of the Oregon and Washington ex-vessel port markets. The demand and supply at the different ports are estimated by applying regression analysis to 32 different sets of data. These data include a single year (1976) of transaction records for the twelve Oregon ports, and four years (1973-1976) of landings records for the five Washington coastal ports. Three different models are used; a simultaneous equations model, a recursive model, and a single equation model. The major findings in the study are as follows: the ex-vessel demand in most Oregon or Washington ports is highly elastic, which suggests that changes in seasonal landings at a port do not have any significant impact on the ex-vessel price. While fishermen and other industry observers have noted differences in seasonal ex-vessel price between ports, such differences do not appear to exist. Average seasonal price differences between ports do not vary when appropriate weights are applied to the average price calculations. The size (in pounds) of the coho salmon plays a major role in the determination of the intraseasonal ex-vessel demand at all ports. Estimations performed without accounting for this variation fail to adequately explain ex-vessel price variation. Another variable found to be a key factor in the explanation of ex-vessel prices is the wholesale price. This factor and the size variable accounted for most of the variation in ex-vessel port prices. Even though the seasonal prices between ports are similar, the intraseasonal variation in port price is partly the result of competition for the fisherman's catch of coho. When two ports are located in such a way that fishermen may easily land at either one, fishermen appear to land at the port where price is greater. Ports such as La Push and Neah Bay in Washington, and Bandon and Winchester Bay in Oregon are the ports found to be alternative ports for the fishermen catching coho in those areas. Coastal ex-vessel prices do not appear to be established as a result of equilibrium conditions at any particular port. Rather, ex-vessel price and market clearing quantities are determined in the aggregate. Each port's buyers will establish port price based on the current aggregate equilibrium condition. The aggregate coastal demand for coho at the ex-vessel level was estimated for the 1976 season and found to be highly price elastic. Given that aggregate supplies are augmentable, increases in coastal landings will increase total returns to the ex-vessel fishery. One additional finding suggests that the number of buyers in most ports does not play a significant role in the determination of intraseasonal variation of port ex-vessel prices. / Graduation date: 1979

Today in the United States, herbal supplements are growing increasingly popular, however, little is known about the safety and efficacy of these products. This study contributes to the growing body of information about the prevalence of herbal supplement use among young adults (18 to 24 years) and the beliefs young adults hold about herbal supplements in relation to their dietary attitudes and behaviors. A self-administered, four-part questionnaire was mailed to a geographically representative sample of 298 young adults (18 to 24 years) residing in Oregon; 205 questionnaires were usable (69% response rate). There was an equal ratio of male and female respondents, half students and half non-students, the majority being Caucasian (93%), with a mean age of 21.5 years. Nearly 60% of the sample reported using herbal supplements (n=122). Thirty-seven percent were sometime users (less than weekly) and 22% were regular users (at least weekly). More female respondents reported using herbal supplements (69%) than did male respondents (49%). Respondents who were White or Asian/Pacific Islander were the only ethnic groups that reported using herbal supplements regularly. Users were more educated than non-users, however use was very similar among students and non-students. Herbal supplement use also was very similar between respondents having different residencies. Familiarity with different herbs was positively related to level of herbal supplement use. Regular users were familiar with the greatest number of herbs, followed by sometime users. Herbal supplement users tended to have more healthful lifestyle characteristics than non-users. Frequency of fast food patronage was negatively related to level of herbal supplement use. The median number of times a fast food restaurant was patronized was lower among regular users of herbal supplements than among those who did not use supplements or used them less often. The median number of times breakfast was eaten also seemed to be slightly higher among regular users than other groups. Other healthful lifestyle characteristics, such as BMI and drinking in moderation, did not tend to be more healthful among herbal supplement users. The results were mixed on smoking behavior. Regular users of herbal supplements were no more or less likely than non-users to smoke, but non-users were less likely than sometime users to smoke. Regular users of herbal supplements tended to think herbal supplements are useful for certain health parameters more often than sometime users and non-users. Most regular users of herbal supplements agreed herbs are useful for maintaining good health (89%) and preventing/treating common illnesses like colds (85%). Almost two-thirds also thought herbs are useful for preventing serious chronic illnesses (61%) and insuring a well-balanced diet (65%). Attitudes toward the effectiveness, convenience, and expense of taking herbal supplements in comparison to eating a balanced diet as ways of staying healthy were related to herbal supplement use. Herbal supplement users did not appear to have positive attitudes towards herbs when comparing herbs to a well-balanced diet. Only 11% of users thought that herbs are more effective than diet as ways to stay healthy, and users were more likely than non-users to think herbs are more expensive ways to stay healthy. However, both levels of users were more likely to think herbal supplements are more convenient than diet. Attitudes about the effectiveness, safety, expense, naturalness, potency, and personal control of taking herbal supplements in comparison to prescription medications was related to level of herbal supplement use. In general the trend was for users to be more likely to have positive attitudes toward herbs and less likely to give a "don't know" answer. Eating the recommended number of food guide pyramid servings of fruits and vegetables as well as eating a greater number of nutrient rich vegetables was not related to herbal supplement use. However, a somewhat higher percentage of herbal supplement users tended to meet the fruit and vegetable recommendations than nonusers of herbal supplements. Stage of change in relation to vegetable intake was related to herbal supplement use. As respondents' herbal supplement use increased, so did the likelihood of classifying themselves into one of the action stages of change for vegetable consumption. Stage of change for fruit consumption was not related to herbal supplement use. Choice to stop using herbs if they were pronounced unsafe by a governmental agency was not related to level of herbal supplement use. However, 17% of sometime users and 16% of regular users reported that they would continue to use herbs even after they were pronounced unsafe by a governmental agency. The results of this study clearly show that there is a high prevalence of herbal supplement use among young adults in Oregon, and those who are using herbal supplements seem to have a strong belief in the herbs they are taking. With the limited knowledge on herbs' safety and efficacy, young adults need to be educated about the herbs they are using. Hopefully, the information from this study can help health professionals identify which young adults might be using herbal supplements in order to educate them on making smart choices about herbs, and smart choices about their overall health. To inform young adults about the herbs they are using, additional research on herbal supplements' potential benefits and harmful side effects is needed. / Graduation date: 2002

The impact of Oregon's Special Use Assessment (SUA) program was analyzed in relation to farmland values in six regions. Data for the study were obtained from the Oregon Landownership Survey. Data were based on 1975 assessment and ownership characteristics. Farmland value per acre, including improvements, was believed to be influenced by the following factors: special use assessment, gross farm income, population growth rate, income of owner, occupation of owner, distance to the nearest urban area, size of tract, and improvements value. Ordinary least squares was used to test the impact of these factors on farmland value per acre. Tax savings, if any, resulting from SUA were expected to be capitalized into higher farmland values. Study results indicate that SUA did increase farmland values in four of the six regions. In the Coastal region, SUA on unzoned farmland increased values by $932 per acre. In the Valley region, SUA on exclusive farm use (EFU) zoned and unzoned farmland increased values by $977 and $1721 per acre, respectively. SUA increased unzoned farmland values by $1226 per acre in the Southwestern region but had no significant impact on zoned farmland. The value of zoned and unzoned farmland in the Northcentral region was increased by $453 and $865 per acre, respectively. SUA did not have a significant impact on zoned or unzoned farmland values in the Southcentral or Eastern regions. Therefore, it is assumed SUA does not provide tax relief in these regions. This result may be due to the large agricultural tax base in these regions. A large portion of the tax base is reduced by SUA, which necessitates an increase in the tax rate to maintain the same level of county revenues. Therefore, little if any tax relief is realized by the participating farmland owners. The restrictive effect of EFU zoning was expected to offset tax benefits resulting from SUA. As indicated above, there was a difference in the impact of SUA on EFU zoned as compared to unzoned land in the Valley, Southwestern,and Northcentral regions. The impact on zoned land was consistently smaller than on unzoned land in all regions (except the Southcentral where both were not significant). Most of the other variables in the model had the expected signs. Those that did not were not significantly different from zero (except for the distance variable in the Valley region which was explained after closer analysis). Tax savings and the resulting increases in farmland values represent a redistribution of income from nonparticipants to participants in the SUA program. In order to determine who was benefiting from SUA, participants were compared to nonparticipants on a number of ownership characteristics. Participants and nonparticipants did not differ on all characteristics in all regions. However, where there were differences, participants were more likely to be residents, farmers, own land further from urban areas, not have plans to sell their land, own larger acreages, and be in higher income and net worth classes compared to nonparticipants. The tax saving resulting from SUA may be sufficient to prevent a farmer from being forced out of farming. However, the program is not designed to prevent farmland conversion if the owner desires to change use. A circuit-breaker tax program for farmers and EFU zoning merit closer attention as possible alternatives of providing tax relief and farmland preservation. / Graduation date: 1979