REU Mentors and Projects
Below are the faculty who have volunteered to work with REU students in the summer of 2013. Click on a faculty member's name to read more about her or his research.
Most climate-change models for the Great Lakes region predict long-term reductions in
precipitation and lower Great-Lakes water levels. Great Lakes water levels have been low since 1998, the longest period of low water levels recorded. Related to this, I have two research projects on bulrush species in the Great Lakes:
Topic 1: We are proposing to look at the response of three square bulrush (Schoenoplectus pungens) and hardstem bulrush (S. acutus) root and rhizome growth rates and structural changes at Cecil Bay, where they have expanded outward into previously unoccupied habit since 1998. Cecil Bay is about 15 miles from UMBS on Lake Michigan.
Topic 2: We are proposing to look at both stem and root competition between hardstem bulrush (Schoenoplectus acutus) and sedges (Carex spp.) that have grown out into the bulrush beds during the last 15 years of low water, and compare these mixed plant beds with beds of pure hardstem bulrush in nearby wetter habitat. Work will be done at Mackinaw Bay near Cedarville, about 55 miles from UMBS.
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.
Behavioral Ecology: Sexual Selection, Sexual Conflict, Insect Conservation
I am a behavioral and evolutionary ecologist who uses dragonflies and damselflies to ask questions about the evolution of reproductive strategies. At UMBS, I have on-going research on the evolution of female-specific color polymorphisms in Enallagma damselflies. However, past REU students have worked with me on the effects of invasive zebra mussels on the fitness of native dragonflies (e.g. Hagenius brevistylus, Macromia illinoisensis). Because dragonflies are important predators both as larvae and adults, negative effects of colonization by zebra mussels could have direct impacts on aquatic and terrestrial food webs. I am currently quantifying the fitness consequences of zebra mussel colonization on dragonfly larvae, as well as the relative abundance of the adult dragonflies as part of a long-term monitoring program related to this project. I would welcome students to work on any of the above topics, or any more broadly related to behavioral ecology of insects.
Chris Gough, Peter Curtis, Chris Vogel and Lucas NaveForest Carbon Cycling in Future Forests of the Upper Midwest: Implications for Climate Change
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.
Student collaborators on the UMBS Forest Carbon Cycling Research Team could investigate: 1) how shifts in canopy structure and composition alter forest carbon cycling; 2) mechanisms behind sustained high rates of carbon storage in a maturing forest; and 3) changes in soil carbon pools and fluxes following partial canopy defoliation.
Dave Karowe1) Rising Carbon Dioxide and Plant Defense Against Herbivores; 2) Insect-Eating Plants: Where Does Their Nitrogen Come From?
I would be happy to mentor REU students in either of two research areas:
I. 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.
II. 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, and/or 2) which plant traits (e.g. coloration, microhabitat) affect the proportion of nitrogen derived from insect prey.
Great Lakes coastal wetlands are species-rich, dynamic habitats that connect terrestrial and aquatic ecosystems. Globally, wetlands are a significant carbon pool, but the contribution of Great Lakes coastal wetlands to regional carbon cycling remains relatively uncertain. An REU student working with us could quantify and compare carbon storage in Lake Michigan and Lake Huron coastal wetlands across a range of hydrogeomorphic classes (e.g.: drowned river mouths, open embayments, ridge-swale complex) and/or vegetation communities (e.g.: wet meadow, emergent marsh, submergent). This study would contribute to a larger project investigating the effect of climate change and invasion by dominant macrophytes on the carbon accumulation rates in Great Lakes coastal wetlands.
Organisms make ecological and evolutionary decisions are based off of information about their environment gathered through their senses. My lab studies how organisms acquire information about their aquatic world using visual, auditory, and chemical cues. In addition, we study how those organisms use this information for mating, fighting, avoiding predation and other important ecological decisions.
Predicting how forests will slow future climate change by absorbing CO2 requires understanding of how plant-atmosphere interactions influence forest carbon uptake. This includes (1) how atmospheric cloud conditions change radiation available for photosynthesis and (2) how shifting tree species composition in natural and managed forests changes forest canopy structure and subsequent light use. One-dimensional land-atmosphere modeling can identify how forest-atmosphere interactions influence carbon uptake. However, adding and evaluating biological details into these models is limited by the availability of empirical data.
The student collaborator on this project will primarily collect data in the field for model development on (1) how light and leaf temperature change in forest canopies and (2) on how leaf photosynthesis changes under different light and temperature conditions. Field work will include working in a boom lift, climbing towers, and using ladders to measure leaf-level photosynthesis and atmospheric conditions in forest canopies. The student researcher could also investigate effects of nitrogen on photosynthesis, which would involve some lab work.
Nitrogen availability controls the rate at which temperate forests remove carbon from the atmosphere, helping to counteract the influence of anthropogenic CO2 emissions on earth's climate. There is much to be learned about how disturbances such as large-scale tree mortality affect the N cycle, and the question of how N availability changes over the course of forest succession is also surrounded by unresolved questions.
REU students have the opportunity to study forest N cycling at the FASET (Forest Accelerated Succession ExperimenT) site at UMBS with a team of researchers from the University of Michigan as they seek to answer several questions through field and lab research: 1) How large is the increase in nitrogen availability that occurs when trees die? 2) Which plant, soil, and microbial pools are the most important for retaining excess nitrogen during the period of high N availability following tree mortality? 3) How much do mycorrhizal fungi contribute to the nitrogen requirement of tree growth?
My research interests include examining the effects of wetland ecology, algal taxonomy and ecology, effects of zebra mussels on aquatic systems, and using multivariate statistical techniques to find patterns in large datasets. I am also working on ecology of invasive algae in Lake Superior.
Several possible suggestions for projects include assessing the effects of zebra mussels on the native clams of Douglas Lake, changes in algal communities as wetlands change, and determining the effect of grazers on the nutrient cycling rates of periphyton at the experimental stream lab.
My research concerns the natural selection of social behavior. Emphasizing quantitative and experimental approaches in the study of natural populations, I am interested in sexual selection, communication, and sexual signaling. During the summer months at the University of Michigan Biological Station (UMBS), my research focuses primarily on damselflies, investigating aspects of communication, coloration, and sexual selection.
Following previous work on damselflies, an REU student could investigate the effects of gregarine parasites on the biology, behavior, and morphology of Calopteryx maculata, the dark-winged damselfly. The work will involve fieldwork, behavioral observations, collecting damselflies, analysis of coloration using a spectrometer, and analysis of parasite loads.
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.
My research interests are at the boundaries of aquatic and terrestrial ecosystems. Animals in terrestrial ecosystems, such as moose, have the potential to affect aquatic systems as they forage in lakes for aquatic plants and stir up both sediment and nutrients in lakes. This bioturbation has the potential to affect lake nutrient dynamics and consequently lake communities. A potential project would be to combine field and lab studies to examine the effects of bioturbation on nutrient availability to aquatic plants.
A second area of research is the effects of vernal pools in the landscape. Vernal pools are small
wetlands that are filled with water in the spring, but subsequently dry during the summer. These
habitats are critical for a variety of amphibian species but are also important for terrestrial species such as, bats, birds, small mammals and reptiles. Potential student projects include examining amphibian species diversity across vernal pool types, or spatial distribution of bats at vernal pools during the summer.