Humans are increasing the scale and frequency of many natural disturbances, as well as adding novel disturbances to ecosystems. This thesis uses the arthropod community as a metric to examine the multi-trophic responses to disturbances in California grasslands. Chapter 2 explores how the long-term exclusion of native vertebrate herbivores has...
The purpose of this article is to report the results of a statistical investigation of links in the fish supply chain in Uganda. We are particularly interested in the extent of ex-vessel prices impacting links downstream in the fish supply chain. We test for vertical and horizontal co-integration for five...
Vertical Axis Pendulum Wave Energy Converters (VAPWECs) are thought to be both effective and robust at converting ocean wave energy into usable electricity. Seeking to build upon and investigate such potential, this work examines the merits of actively controlling a generic VAPWEC's pendulum for the purpose of increasing the converter's...
The vertical propagation of Coastal Trapped Waves (CTWs) due to subsurface ridges is explored with the help of linear numerical and analytical models. Results show that submerged ridges projecting from the shoreline can scatter a horizontally propagating single baroclinic mode Kelvin wave into both upward and downward propagating Kelvin wave...
Direct measurements of vertical water motions were made in
the Oregon coastal region during the 1972 summer upwelling season.
The instruments used were the Webb-Voorhis vertical current meters
which are freely drifting neutrally buoyant floats capable of sensing
vertical motion. It was found that in the region studied, water tended...
A 50 m² pelagic trawl equipped with a codend opening-closing device was used to sample micronektonic fishes between 500 m and 1000 m. Horizontal tows were made at 500, 650, 800 and 1000 m. Twelve of 15 common species captured showed significant diel differences in abundance at one or more...
In situ salinity, turbidity and temperature were measured at discrete depths and water samples for radioanalysis were simultaneously collected in the Columbia River Estuary using a specially designed instrument package. Particulate radioactivity was concentrated by filtration and the dissolved radioactivity by evaporation or ferric oxide bulk precipitation. Radioanalysis was by...
A study has been made of the vertical distributions and
migrations of a large number of zooplankton species at Weather
Station "P" in the Subarctic Pacific. Simultaneously towed horizontal
opening-closing nets were used for the study. The distributions
and migrations of 104 taxa have been subjectively grouped
into seven basic...
Discrete layers of phytoplankton and zooplankton were observed over the Oregon continental shelf in summer and fall of 2001 and summer 2002 using optical and acoustical technologies and a pump sampling system. Layers of phytoplankton had steep vertical gradients which were associated with gradients in density and local peaks in...
This report is an intermediate step in analyzing part of the hydrographic data from the 1972 Coastal Upwelling Experiment (CUE) off the coast of Oregon. It presents the author's interpretation of the vertical distribution of temperature, salinity and sigma-t along lines occupied on hydrographic cruises by R/V Yaquina during CUE....
Falls in older adults are a significant issue in the United States. Many older adults are advised to participate in fall prevention exercise programs in an attempt to increase strength and stability, but it is unclear what role limb dominance and potential limb asymmetry has in exercise performance. The purpose...
Comprehensive observations of velocity, density, and
turbulent dissipation permit quantification of the nonlinear
internal wave (NLIW) contribution to vertical heat flux and
lateral mass transport over New Jersey’s shelf. The effect of
NLIWs on the shelf heat budget was significant. On
average, heat flux in NLIWs was 10 times larger...
Comprehensive observations of velocity, density, and
turbulent dissipation permit quantification of the nonlinear
internal wave (NLIW) contribution to vertical heat flux and
lateral mass transport over New Jersey’s shelf. The effect of
NLIWs on the shelf heat budget was significant. On
average, heat flux in NLIWs was 10 times larger...
The simplified equations of motion proposed by Morton to determine
the extent of vertical travel of a forced plume in a linear
density stratified environment were re-written and solved in a way
which allowed them to be applied to any non linear profile of density.
For application to any specific...
In this report we will present vertical sections of temperature, salinity and sigma-t from both CTD and bottle casts made on legs 1-5 of the R/V Eastward during JASON, and from CTD casts made on legs 1, 2 and 4 of the R/V Melville and legs .2 and 4 of...
As part of the Peru Currents study, CTD observations were made between February 1983 and April 1985 between 3° N to 17° S off the coasts of Peru and Ecuador. Vertical sections of temperature, salinity and sigma-theta vs
depth from 0 to 625 m are presented for each section completed...
Methods for obtaining accurate, spatially explicit estimates of biomass density in tropical forests are required to reduce uncertainties in the global carbon cycle, and to support international climate agreements and emerging carbon markets. Three-dimensional (3-D) remote sensing techniques sensitive to the vertical structure of vegetation provide a unique opportunity for...
The structure of turbulence in a strongly stratified nocturnal boundary layer is studied using fast-response aircraft data collected under clear sky conditions with weak ambient flow. The principal source of turbulence is shear generation near the top of the surface inversion layer. This shear is induced by the development of...
A method for predicting oceanic productivity from remotely sensed diffuse attenuation (488 nm) and
surface chlorophyll concentration is presented. The method uses a climatological approach which consists
of applying a set of regressions for each region and season to yield the depth of the chlorophyll maximum,
the exponential slope of...
The Arctic climate system is changing dramatically as a response to rising atmospheric greenhouse gas concentrations. Key indicators of Arctic change include thinning and retreating of Arctic pack ice, thawing permafrost, greening tundra, and rising surface temperatures. The structure of the atmospheric boundary layer influences and is influenced by processes...
Air passing upward through the tropical tropopause is “marked” by an annually varying water vapor mixing ratio much as a tape recorder marks a magnetic tape; as the air ascends in the tropical stratosphere, these marks are effaced by a combination of vertical diffusion within the tropics and dilution of...
Marine protected areas (MPAs), ideally, manage human uses that threaten ecosystems, or components of ecosystems. During several recent MPA designation processes, concerns have arisen over the scientific justification for no-take MPAs, particularly those that restrict recreational fishing for pelagic species. An important question is: under what conditions might recreational pelagic...
The stable nocturnal boundary layer is commonly viewed or modelled as a balance between the temperature tendency (cooling) and vertical heat-flux divergence. Sometimes the radiative-flux divergence is also included. This perspective has dictated the design of field experiments for investigating stable nocturnal boundary layers. Tower-based micrometeorological data from three field...
Published February 1980. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Published June 1936. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Verticillium wilt of hops in Oregon, caused by Verticillium
dahliae Kleb., was first reported in 1956. Later, V. albo-atrum
Reinke & Berth. was also isolated from infected hop plants, and thus
both species of the fungus were shown to be the causal agents of the
disease in Oregon.
The purpose...
Published January 1936. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Verticillium wilt of 'Willamette' hops (Humulus
lupulus) was investigated to identifY the causal organism,
to determine the incidence of the disease, and to explore
the possibility of interactions with soil fertility and/or
nematodes. In the first year of a three year study,
sampling of yards followed a "searching for extremes...
Physical inactivity and unhealthful diet are major risk factors for noncommunicable diseases, and strategies worldwide now focus on improving diet and encouraging physical activity (PA). Participation in PA lowers the risk for numerous chronic diseases, while a healthful diet also offers resistance to disease. However, practicing both behaviors offers greater...
Eleven years (1932-1942) of electric potential and magnetic measurement at the Tucson observatory
represent a unique very long period magnetotelluric (MT) data set. We report here on a careful reanalysis of this
data using modern processing techniques. We have developed and used novel methods for separating out the
quasi-periodic daily...
In a companion paper (Egbert et al., this issue) we describe the estimation of very long period (0.16 < T < 91 days) magnetotelluric (MT) impedances from 11 years of data collected at the Tucson geomagnetic observatory. Here we discuss the implications of these data for mantle conductivity. Using minimum...
Published September 1980. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the Sea Grant Catalog: http://seagrant.oregonstate.edu/publications
The paper presents a vessel level simulation model of the impact of a landing obligation on a typical Scottish demersal trawler under a discard ban in addition to existing quota management controls. The simulation model is based on a simple microeconomic model of firm behaviour and predicts landings, discards and...