2008 REU Mentors

Dennis Albert, Michigan State University Extension (albertd@msu.edu)
Vegetative reproduction of bulrushes (Schoenoplectus acutus and S. pungens).  Hardstem and three-square bulrushes are dominant plants along the Great Lakes shoreline near the Straits of Michigan, as well as along the shoreline of Douglas Lake.  Bulrushes are keystone species, stabilizing sediments in a high-energy environment and providing critical habitat for fish and aquatic invertebrates.  As Great Lakes water levels have dropped over the last ten years, many extensive bulrush beds are no longer flooded, greatly reducing faunal habitat.  This study will investigate the annual rate of rhizome growth for both species of bulrush, providing information relevant to future restoration efforts along the Great Lakes and inland lakes.  Study sites will be located along the Lake Huron, Lake Michigan, and Douglas Lake shorelines.  This project could provide opportunities for two students and would require students to have their own vehicle.

Harvey Blankespoor, Hope College(http://www.hope.edu/academic/biology/faculty/blankespoor.htm)
Host-parasite relationships, behavior and ecology of digenetic trematodes, particularly avian schistosomes that cause swimmer's itch.

Mary Anne Carroll, University of Michigan 
(http://aoss.engin.umich.edu/go/?id1=10&id2=1&id3=8)
Ozone and Volatile Organic Compounds.  Increasing near-surface atmospheric ozone (O3) is a concern because it is toxic to humans and ecosystems.  Ozone is formed in the atmosphere through reactions involving carbon monoxide (CO) and reactive nitrogen oxides (produced by fossil fuel combustion) and volatile organic compounds (VOCs) (emitted by vegetation and by human activities).  At the PROPHET site, ambient measurements of O3 and CO and flux measurements of O3 and isoprene (an important VOC) are being made.  REU students working with me could help us investigate (1) how near-surface atmospheric ozone levels are changing; (2) the relationship between CO and O3 in different air masses; or (3) how exposure to atmospheric ozone affects the emission of isoprene by plants.

Ola Fincke, University of Oklahoma (http://faculty- staff.ou.edu/F/Ola.M.Fincke-1/)
Effects of Zebra Mussels on Dragonflies.  As a recent invasive species of Douglas  Lake, the zebra mussel (Dreissena polymorpha) has quickly become a threat to the lake's native bivalves. This exotic species has also started to colonize the larvae of native dragonfly species (e.g. Hagenius brevistylus and Didymops transversa), but its effects on these odonates are less obvious. Because dragonflies are important predators both as larvae and adults, the mussel could have direct impacts on terrestrial habitats. A student could help in our continuing work by 1) quantifying the extent to which the mussel colonizes the various instars of larval dragonflies, and 2) how colonization by mussels affects feeding rates and escape behavior of dragonfly larvae. 

MENTOR TEAM: 
Chris Gough, Ohio State University 
(http://www.biosci.ohio-state.edu/~pcurtis/People/Christopher%20Gough/index.html);
Peter Curtis, Ohio State University
(http://www.biosci.ohio-state.edu/~pcurtis/);
Chris Vogel, University of Michigan Biological Station (http://www.umich.edu/~umbs/edu/staff/vogel.html)
Forest Carbon Cycling in Future Forests of the Upper Midwest: Implications for Climate Change.  By absorbing atmospheric carbon dioxide, forests are slowing the rate of global climate change.  However, some forests, including those in northern Michigan, will soon experience a phase in which loss of carbon through the death of old trees may exceed absorption of carbon by younger trees, causing the forest to shift from a carbon sink to a carbon source.  A similar shift could happen to forests after a pest outbreak or other natural disturbance.  We recently initiated a large-scale experiment to examine how disturbance-related changes in forest composition and structure alter carbon cycling processes in the UMBS forest (http://www.biosci.ohio-state.edu/~pcurtis/UMBS%7EFlux/index.htm).  Student collaborators on the UMBS Forest Carbon Cycling Research Team could investigate 1) changes in soil carbon pools and fluxes following partial canopy defoliation; 2) leaf-level changes in photosynthesis after canopy disturbance; and 3) the relationship between severe precipitation events and leaf litter decomposition and respiration.

Dave Karowe, Western Michigan University  (http://homepages.wmich.edu/~karowe/research.html)
Rising Carbon Dioxide and Plant Defense Against Herbivores.  Rising atmospheric carbon dioxide, caused by the burning of fossil fuels, is causing plants to have higher levels of carbon but lower levels of nitrogen in their leaves.  Today, most plants can respond to attack by herbivores by rapidly increasing their levels of chemical defenses, but this is a nitrogen-intensive response because it requires rapid synthesis of RNA and enzymes.  A student working with me could investigate whether, when grown under the CO2 levels our atmosphere will have at the end of the century, plants 1) have higher pre-attack levels of carbon-based chemical defenses, due to higher carbon content of leaves, but 2) are less able to respond to attack by increasing levels of these same chemical defenses, due to lower nitrogen content of leaves.

Insect-Eating Plants:  Where Does their Nitrogen Come From?  Insectivory, the eating of insects, is one of the most dramatic adaptations of plants to low-nutrient environments.  In Northern Michigan, nitrogen-poor bogs and swales contain two plant species that have evolved insect-eating leaves:  pitcher plants and sundews.  While it is a common belief that such plants obtain a substantial portion of their nitrogen from insects, few studies have actually demonstrated this (pitcher plants and sundews also have roots that can absorb nutrients from the slowly decaying plant matter).  An REU student could use stable nitrogen isotopes to determine 1) what fraction of the plant's nitrogen is obtained from insects, 2) whether the proportion of nitrogen derived from insect prey differs between pitcher plants from different habitats, and 3) whether it differs between pitcher plants and sundews.

Troy Keller, Columbus State University (http://faculty.colstate.edu/newfacfa06.htm)
Rusty Crayfish Invasion.  The rusty crayfish (Orconectes rusticus) is an aggressive introduced species that is in the process of displacing native crayfish from many aquatic habitats in northern Michigan.  A student could determine 1) the current pattern of its distribution across northern Michigan; 2) how environmental conditions influence this crayfish's invasion success.

Zebra Mussel Effects on Lakes.  The zebra mussel (Dreissena polymorpha) has recently invaded a number of lakes in northern Michigan, including Douglas Lake at the University of Michigan Biological Station.  A student could help determine 1) to what degree zebra mussels have colonized local lakes and 2) how the lake depth, size, and substrate influence the zebra mussel populations and their effects on lake trophic dynamics

Rex Lowe, Bowling Green State University
http://www.bgsu.edu/departments/biology/people/faculty/lowe.html
Impact of Invasive Species on Littoral Zone Food Webs. Recent invasions of exotic species into North American freshwater ecosystems are resulting in a multitude of alterations of energy flow in food webs.  In this project students will investigate the effects of selected invasive species within the Great Lakes and or other aquatic ecosystems in order to predict the present and future impact of exotic species invasions.

Phil Myers, University of Michigan
http://www.eeb.lsa.umich.edu/eeb/people/pmyers/index.html
Climatic warming and small mammals.  Assemblages of small mammals in northern Michigan are changing rapidly.  Southern species are replacing northern ones, probably as a result of our warming climate.  Because of their small body size and extraordinarily high metabolic rates, shrews should be among the first mammal species affected by climate change.  Unfortunately, while information on past distribution and abundance of shrew species is available in the form of museum records, few recent data are available.  I'm looking for a student who would be interested in (1) surveying broadly for shrews using live-trapping techniques, and (2) working on a quantitative comparison of shrew abundance now and in the past.

Steve Pruett-Jones, University of Chicago
(http://pondside.uchicago.edu/ecol-evol/faculty/pruett-jones_s.html)
Behavioral ecology and sexual selection in insects and birds. Behavioral ecology, sexual
selection, social behavior, communication, and natural history of birds and insects.

Brian Scholtens, College of Charleston   (http://www.cofc.edu/~biology/directry.htm#scholtens)
Nitrogen and Dune Systems.  Work on dune systems in various parts of the world has indicated that they are often nitrogen poor environments.  In some systems, a significant portion of available nitrogen originates in the adjacent aquatic habitats.  Northern Great Lakes dunes may show this same pattern.  Work on one grasshopper species indicates that it supplements its diet by consuming aquatic insect adults, thereby moving nitrogen from the aquatic habitat into the dune habitat .  An REU student could follow the fate of this valuable nitrogen through multiple parts of the ecosystem using isotope ratios.  A student could focus on the fate of nitrogen or how particular species, such as the grasshopper, make use of this nitrogen.

Allison Snow, Ohio State University
(http://www.biosci.ohio-state.edu/~eeob/faculty/snow.html)
Hybridization and Invasiveness in Cattails.  Spontaneous crosses between common cattail species in North America have resulted in hybrid populations that may be more invasive than their parents.  Typha latifolia (broad-leaved cattail) is native to North America, while T. angustifolia (narrow-leaved cattail) is considered to be invasive and is thought to have been introduced from Europe in the mid-nineteenth century.  Their first-generation hybrid, known as T. x glauca, is very vigorous but mostly sterile.  Despite concerns about the competitiveness and rapid spread of T. x glauca, little quantitative data has been published on its genetics, ecology, or relative invasiveness compared to its parent species.  An REU student could compare the growth and competitive ability of F1 hybrids, backcrossed plants, and the two parent taxa to test for differences in potential invasiveness.  A student could also survey wetlands in Michigan to gain a better understanding of the frequency of hybrid populations using a combination of morphological traits and molecular markers.  Students working on this project will need a car for field work.

Nancy Tuchman, Loyola University of Chicago(http://www.luc.edu/depts/biology/tuchman.htm)
Invasive Cattail and Wetland Nitrogen Cycling.  A non-native invasive wetland plant (Typha x glauca, cattail) is beginning to dominate many of the coastal wetlands in the upper Great Lakes, significantly reducing biodiversity, and altering wetland ecosystem function.  In what seems to be a positive feedback mechanism, this aggressive plant is perpetuated by the organic carbon it puts into the soils which, in turn, stimulates N2-fixing bacteria to provide much-needed nitrogen to the plants.  A student working with me could investigate portions of the nitrogen cycle that are directly or indirectly modified by the invasive cattail including denitrification, nitrogen fixation, mineralization, plant uptake of soil N, and plant stomatal uptake of atmospheric NOx gasses.