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Physical Sciences and Mathematics Commons

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Full-Text Articles in Physical Sciences and Mathematics

Understory Species Patterns And Diversity In Old-Growth And Managed Northern Hardwood Forests, Robert M. Scheller, David J. Mladenoff Oct 2002

Understory Species Patterns And Diversity In Old-Growth And Managed Northern Hardwood Forests, Robert M. Scheller, David J. Mladenoff

Environmental Science and Management Faculty Publications and Presentations

Forest management can significantly affect both the diversity and spatial patterning of understory vegetation. However, few studies have considered both diversity and spatial patterning at a stand scale. Our objective was to evaluate the effects of forest management on understory plant communities in northern hardwood forests and assess the processes governing differences in species composition, diversity, and spatial patterns. We sampled understory vegetation (all speciestall) and percentage of light transmission levels in three forest types in 12 mesic northern hardwood stands in northern Wisconsin and the Upper Peninsula of Michigan, USA: old-growth, undisturbed forests; even-aged forests resulting from clearcut logging …


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° …


Authentic Field Ecology Experiences For Teachers, Marion Dresner, Andrew Moldenke Jan 2002

Authentic Field Ecology Experiences For Teachers, Marion Dresner, Andrew Moldenke

Environmental Science and Management Faculty Publications and Presentations

This paper will focus on one teacher field research experience situated in the Pacific Northwest


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 …