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Ecology and Evolutionary Biology

2002

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Articles 31 - 39 of 39

Full-Text Articles in Physical Sciences and Mathematics

Comparison Of The Fate Of Dissolved Organic Matter In Two Coastal Systems: Hog Island Bay, Va (Usa) And Plum Island Sound, Ma (Usa), Tami L. Lunsford Jan 2002

Comparison Of The Fate Of Dissolved Organic Matter In Two Coastal Systems: Hog Island Bay, Va (Usa) And Plum Island Sound, Ma (Usa), Tami L. Lunsford

Dissertations, Theses, and Masters Projects

No abstract provided.

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Stomatal Responses Of Douglas-Fir Seedlings To Elevated Carbon Dioxide And Temperature During The Third And Fourth Years Of Exposure, James D. Lewis, Melissa S. Lucash, David M. Olszyk, David T. Tingey Jan 2002

Stomatal Responses Of Douglas-Fir Seedlings To Elevated Carbon Dioxide And Temperature During The Third And Fourth Years Of Exposure, James D. Lewis, Melissa S. Lucash, David M. Olszyk, David T. Tingey

Environmental Science and Management Faculty Publications and Presentations

Two major components of climate change, increasing atmospheric [CO2] and increasing temperature, may substantially alter the effects of water availability to plants through effects on the rate of water loss from leaves. We examined the interactive effects of elevated [CO2] and temperature on seasonal patterns of stomatal conductance (gs), transpiration (E) and instantaneous transpiration efficiency (ITE) in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings. Seedlings were grown in sunlit chambers at either ambient CO2 (AC) or ambient + 180 µmol mol-1 CO2 (EC), and at ambient temperature (AT) or ambient + 3.5° …

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Microbial Ecology Of Ballast Water During A Transoceanic Voyage And The Effects Of Open-Ocean Exchange, Lisa A. Drake, Gregory M. Ruiz, Bella S. Galil, Timothy L. Mullady, Daniela O. Friedmann, Fred C. Dobbs Jan 2002

Microbial Ecology Of Ballast Water During A Transoceanic Voyage And The Effects Of Open-Ocean Exchange, Lisa A. Drake, Gregory M. Ruiz, Bella S. Galil, Timothy L. Mullady, Daniela O. Friedmann, Fred C. Dobbs

OES Faculty Publications

The only procedure used frequently to reduce the risk of invasion by ballast-mediated biota is open-ocean exchange of ballast water, a procedure in which vessels release coastal water and replace it with oceanic water. Limited information exists concerning the effects of transport upon the aquatic microbial community throughout transit and following open-ocean exchange, A transoceanic voyage aboard a commercial bulk carrier afforded us the opportunity to sample the microbial community in exchanged and unexchanged ballast-water holds during the journey from Hadera, Israel to Baltimore, USA. Five days following the exchange process, all microbial metrics tested (i.e. bacteria concentration, virus-like particle …

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Reconnaissance Of Pharmaceutical Chemicals In Urban Streams Of The Tualatin River Basin, Oregon, 2002, Stewart A. Rounds, Micelis C. Doyle, Patrick M. Edwards, Edward T. Furlong Jan 2002

Reconnaissance Of Pharmaceutical Chemicals In Urban Streams Of The Tualatin River Basin, Oregon, 2002, Stewart A. Rounds, Micelis C. Doyle, Patrick M. Edwards, Edward T. Furlong

Environmental Science and Management Faculty Publications and Presentations

A reconnaissance of pharmaceutical chemicals in urban streams of the Tualatin River basin was conducted in July 2002 in an effort to better understand the occurrence and distribution of such compounds, and to determine whether they might be useful indicators of human-related stream contamination. Of the 21 pharmaceutical chemicals and metabolites tested, only 6 (acetaminophen, caffeine, carbamazepine, codeine, cotinine, and sulfamethoxazole) were detected in filtered stream samples from 10 sites. The concentrations of most of the detected compounds were relatively low (less than 0.05 microgram per liter). The most frequently detected compounds were cotinine (a nicotine metabolite, 8 of 10 …

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Distribution Of The Euryhaline Squid Lolliguncula Brevis In Chesapeake Bay: Effects Of Selected Abiotic Factors, I. K. Bartol, R. Mann, M. Vecchione Jan 2002

Distribution Of The Euryhaline Squid Lolliguncula Brevis In Chesapeake Bay: Effects Of Selected Abiotic Factors, I. K. Bartol, R. Mann, M. Vecchione

Biological Sciences Faculty Publications

The majority of cephalopods are thought to have limitations arising from physiology and locomotion that exclude them from shallow, highly variable, euryhaline environments. The brief squid Lolliguncula brevis may be a notable exception because it tolerates low salinities, withstands a wide range of environmental conditions, and swims readily in shallow water. Little is known about the distribution of L. brevis in Chesapeake Bay, a diverse and highly variable estuary. Therefore, a survey of L. brevis was conducted in the Virginia portion of Chesapeake Bay from 1993 to 1997 using a 9.1 m otter trawl, and the effects of selected factors …

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Effects Of Habitat Fragmentation On The Utilization Of Eelgrass (Zostera Marina) By Mobile Epifauna And Macrofauna, Scott R. Marion Jan 2002

Effects Of Habitat Fragmentation On The Utilization Of Eelgrass (Zostera Marina) By Mobile Epifauna And Macrofauna, Scott R. Marion

Dissertations, Theses, and Masters Projects

The threat to biodiversity posed by increasing rates of anthropogenic habitat fragmentation necessitates an understanding of the consequences of spatial pattern for natural communities. Reduction of patch size, loss of habitat, changes in the quantity and proportion of habitat edge, and reduced connectivity among habitats can all shape ecological processes and faunal behavior. Seagrass habitats provide a natural model system for examining spatial inf1uences on marine fauna, but separating the effects of habitat structure, environmental conditions, and spatial pattern is difficult because shoot density, percent cover, and hydrodynamic regime often co-vary with patch size. This study used experimentally manipulated seagrass …

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Organism -Sediment Interactions: The Role Of Seabed Dynamics In Structuring The Mesohaline York River Macrobenthic Community, Elizabeth K. Hinchey Jan 2002

Organism -Sediment Interactions: The Role Of Seabed Dynamics In Structuring The Mesohaline York River Macrobenthic Community, Elizabeth K. Hinchey

Dissertations, Theses, and Masters Projects

Estuaries are dynamic physical environments. The stability of the sediment-water interface is influenced by sources and rates of sediment delivery and physical reworking of sediments by currents, tides, waves and biology, but effects of disruption of this interface on benthic biology are poorly resolved. For this study, I investigated effects of prevalent gradients in seabed disturbance processes and associated seabed characteristics on estuarine benthic community structure and function in the mesohaline York River, a tributary of Chesapeake Bay, USA. I used a variety of approaches to characterize the seabed, including sediment grain size, sediment water content, maximum depth of 7Be, …

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Development Of A Watershed And Stream-Reach Spawning Habitat Model For River Herring Alosa Pseudoharengus And Alosa Aestivalis, Rebecca A. Boger Jan 2002

Development Of A Watershed And Stream-Reach Spawning Habitat Model For River Herring Alosa Pseudoharengus And Alosa Aestivalis, Rebecca A. Boger

Dissertations, Theses, and Masters Projects

This research develops a model to identify indicators of potential suitable spawning habitat for river herring, Alosa pseudoharengus and A. aestivalis, using watershed and stream-reach metrics. The results of icthyoplankton samples collected from thirty-four streams feeding into the Rappahannock River below the Embree Dam at Fredericksburg indicate where river herring spawning occurred. Watershed and stream-reach metrics were either measured in the field or derived from digital data in a GIS. Benthic macroinvertebrate analysis was used to compare habitat quality among sites. Streams were classified as either absence or presence of herring eggs or larvae based on the results of the …

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Coastal Zone Landscape Classification Using Remote Sensing And Model Development, Kevin R. Slocum Jan 2002

Coastal Zone Landscape Classification Using Remote Sensing And Model Development, Kevin R. Slocum

Dissertations, Theses, and Masters Projects

Coastal zone landscape characterization and empirical model development were evaluated using multi-spectral airborne imagery. Collectively, four projects are described that address monitoring and classification issues common to the resource management community. Chapter 1 discusses opportunities for remote sensing. Chapter 2 examines spectral and spatial image resolution requirements, as well as training sample selection methods required for accurate landscape classification. Classification accuracy derived from 25nm imagery with 4m pixel sizes outperformed 70nm imagery with 1m pixel sizes. Eight natural and five cultural landscape features were tested for classification accuracy. Chapter 3 investigated the ability to characterize 1m multispectral imagery into rank-ordered …

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