Environmental Indicators and Impact Assessment Commons^™

Conservation Des Habitats De Roussettes De Livingstone – Les Massifs Forestiers D’Anjouan Et Moheli, Comores: Utilisation D’Indicateurs Sociaux Et Ecologiques, Elise F. Granek

Environmental Science and Management Faculty Publications and Presentations

Le déboisement sur les lles d'Anjouan et Moheli a augmenté a un taux alarmant au cours de ce siecle (PNUD 1998). Ce changement de la couverture des sols et des forets naturelles a des consequences nefastes pour toutes les especes vivant sur les iles, en particulier pour les especes vegetales et animales endemiques, et les communautes humaines locales. Pour diminuer la pression anthropique sur Ie milieu naturel, le Fonds pour l'Environnement Mondial et Ie PNUD ont mis en place un projet de cinq ans qui travaille avec Ie Ministere comorien de l'Environnement pour creer un reseau d'aires protegees dans les …

An Analysis Of Pteropus Livingstonii Roost Habitat: Indicators For Forest Conservation On Anjouan And Moheli, Elise F. Granek

Environmental Science and Management Faculty Publications and Presentations

Livingstone's fruit bat (Pteropus livingstonii) is an endangered and endemic species found only on the islands of Anjouan and Mohéli, Comoros. A study was conducted into the habitats selected by P. livingstonii, as part of a project to assess areas for nature reserves which will be able to protect and conserve forest resources in the islands; the bat is postulated to be a useful indicator of undisturbed forest. Known roost sites (n=9) before the survey were between 500 and 1100 m altitude, on steeply sloping land, with some indigenous forest cover present. Thirteen new potential roost sites were identified, of …

Survey Of Aquatic Plants In Corps Of Engineers Reservoirs, Kimberly D. Walker, Mark D. Sytsma

Center for Lakes and Reservoirs Publications and Presentations

A survey of aquatic plants in a selected Corps of Engineers reservoirs in Oregon was conducted. Cottage Grove, Dorena, Fern Ridge, Dexter and Willow Creek Reservoirs contained abundant aquatic plants. Potamogeton pectinatus and Potamogeton epihydrous were the most common native plant species. Myriophyllum aquaticum and Potamogeton crispus were the most widespread nonnative plants. Species richness in the reservoirs was correlated with trophic status and basin morphology. Shallow reservoirs that included extensive areas of nutrient-rich sediments that were historic flood plain soils supported the greatest biomass and number of species. Mesotrophic reservoirs had lower species diversity. Oligotrophic reservoirs with steep basin …

Final Environmental Impact Statement For The Bal'diyaka Interpretive Center At Gregory Point On The Oregon Coast In Coos County, Joseph A. Maser

Environmental Science and Management Faculty Publications and Presentations

The Confederated Tribes of Coos, Lower Umpqua and Siuslaw Indians, in partnership with the Coos Bay District of the Bureau of Land Management (BLM) are proposing to construct and operate an interpretive center near or on the South Coast of Oregon, near Coos Bay. The Bal'diyaka Interpretive Center is envisioned to contain a 51,000 square foot main building, a recreated coastal Indian village, an ethnobotanical interpretive trail, vehicular circulation and parking, and utilities infrastructure.

This Environmental Impact Statement analyzes four alternatives for this proposed interpretive center. The proposed action of the BLM would locate the Bal'diyaka Interpretive Center on Gregory …

Intercomparison Of Local Hydroxyl Measurements By Radiocarbon And Fage Techniques, Malcolm J. Campbell, Brad D. Hall, John C. Sheppard, Philip L. Utley, Robert J. O'Brien, Thomas M. Hard, Linda Acha George

Environmental Science and Management Faculty Publications and Presentations

A direct intercomparison of near-surface tropospheric HO concentration measurements by two different techniques was made in October–November 1992 at a rural site near Pullman, Washington. The atmosphere at the site is believed to contain low levels of anthropogenic pollution. The instruments' inlets were located at the same height (3.5 m) above the ground and were separated by 10 m along a line normal to the prevailing wind. Readings of the FAGE3 and radiocarbon instruments showed a high correlation (r² = 0.74) despite HO concentrations that were frequently near the detection limit of the instruments. An unweighted least squares regression shows …

Fage Determination Of Tropospheric Ho And Ho₂, Linda Acha George, Thomas M. Hard, Robert J. O'Brien

Environmental Science and Management Faculty Publications and Presentations

FAGE (fluorescence assay with gas expansion) was developed as a sensitive technique for the detection of low-concentration free radicals in the atmosphere. The application of FAGE to tropospheric hydroxyl (H0) and hydroperoxyl (H0₂) radicals has yielded calibrated measurements of both species in both clean air and highly polluted urban air. For HO calibration, a continuously stirred tank reactor provides a uniform external HO concentration, which can be measured by gas chromatography of an HO-reactive hydrocarbon. The aerodynamics of the air-sampling process has been modeled computationally, with results that agree with empirical observations of the effects of nozzle diameter on HO …

Carbon Monoxide In The Antarctic Atmosphere: Observations Of Decreasing Concentrations, M. A. K. Khalil, R. A. Rasmussen

Environmental Science and Management Faculty Publications and Presentations

Hydroxyl radicals remove hundreds, perhaps thousands, of organic gases from the atmosphere and are often regarded as am index of the oxidizing capacity of the Earth's atmosphere (Thompson 1992). In recent years, there have been growing concerns that, over the past century and now, human activities may be depleting hydroxyl concentrations by adding huge amounts of carbon monoxide and methane to the atmosphere. Reduction in the hydroxyl concentrations can then indirectly lead to more global warming, stratospheric ozone depletion, and other disturbances in atmospheric chemistry. Carbon monoxide (CO) is a key component in the determination of hydroxyl radical (OH) concentrations: …

Fage Measurements Of Tropospheric Ho With Measurements And Model Of Interferences, Thomas M. Hard, A. A. Mehrabzadeh, C. Y. Chan, Robert J. O'Brien

Environmental Science and Management Faculty Publications and Presentations

Ambient HO measurements by low-pressure laser-excited fluorescence with chemical modulation, and supporting ozone and water-vapor data, are presented for periods in May and August 1987. The observed peak daytime ambient HO concentrations in Oregon are in the range (2.5 to 8) times106 molecules cm⁻³ and show small negative offsets due to photochemical interference. Direct measurements of the interference at fixed [O₃] give the dependence on ambient [H₂O] and on the modulating reagent [isobutane]. At ambient [O₃]=30 p.p.b. and 10 torr H₂O, with excitation and detection at a total pressure of 4 torr, the net interference is equal to [HO]=-1.3times10⁶ molecule …

Diurnal Ho₂ Cycles At Clean Air And Urban Sites In The Troposphere, Thomas M. Hard, C. Y. Chan, A. A. Mehrabzadeh, Robert J. O'Brien

Environmental Science and Management Faculty Publications and Presentations

HO₂ concentrations have been determined at two Oregon sites for continuous periods of 36 to 48 hours, using fluorescence assay with gas expansion. At the sea level coastal site (45degN 124degW), NNW winds prevailed during daytime, and a point measurement of very low total nonmethane hydrocarbon concentration indicated the presence of remote tropospheric air of oceanic origin. At the urban site, HO₂ was determined during moderately low ozone pollution levels. At both sites, maximum daily [HO₂] was in the range of 1-2times10⁸ cm⁻³ under clear-sky conditions, with an estimated overall uncertainty of 40%.

Studies Of Ecological Factors That Affect The Population And Distribution Of The Western Gray Squirrel In Northcentral Oregon, Susan Ann Foster

Dissertations and Theses

The western gray squirrel (Sciurus griseus griseus Ord) occur only in the Pacific states and in a small corner of extreme western Nevada. Field studies of aspects of the ecology of the most widely distributed subspecies of western gray squirrel (S. griseus) were conducted at three sites in the ponderosa pine-Oregon white oak zone on the eastern slopes of Mt. Hood, Wasco County, Oregon, between 1981 and 1989. From 1981 through 1987, a Hunter Cooperation Program provided remains of squirrels shot during the annual late summer-early autumn hunting season. Other data were gathered through capture and release studies, radiotelemetry, and …

Third-Generation Fage Instrument For Tropospheric Hydroxyl Radical Measurement, C. Y. Chan, Thomas M. Hard, A. A. Mehrabzadeh, Robert J. O'Brien

Environmental Science and Management Faculty Publications and Presentations

The authors have constructed a single-stage, frequency-doubled, copper vapor laser-pumped dye laser to be used in the measurement of atmospheric hydroxyl radical concentrations. This laser can be tuned to either the 1← 0 or 0← 0 vibrational transition in the electronic transition ²Sigmalarr²Pi. A new photon counting instrument is used for HO fluorescence detection. Theoretical and experimental studies of instrument performance show better sensitivities and reduced photolytic interferences than have been possible with previous systems based upon Nd:YAG pumping.

Interference Suppression In Ho Fluorescence Detection, Thomas M. Hard, Robert J. O'Brien, T. B. Cook, G. A. Tsongas

Environmental Science and Management Faculty Publications and Presentations

In this Letter we report preliminary results on a sampling method that greatly reduces the above interferences relative to hydroxyl fluorescence.

"Toxic Chemicals In The Environment", William E. Cooper

Special Collections: Oregon Public Speakers

Presented and recorded with Arbib, M. A., "Environmental Simulation and Long-Term Planning."