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Meet the Powell Center Fellows

By Nicole Tilley and Chris P. Willey

The John Wesley Powell Center for Analysis and Synthesis (Powell Center) enables teams of researchers to collaboratively address complex questions in order to generate new knowledge through the synthesis of diverse Earth system science information. The Powell Center provides support for early career scientists at the graduate or post-graduate level. Powell Center Fellows benefit greatly from interdisciplinary interactions, often working closely with the leaders in their fields. In turn, Powell Center Working Groups gain from having dedicated young scientists who are motivated to process data and publish. We introduce you to some of our Fellows below.

Photo of Daniel Schlaepfer
Daniel Schlaepfer
Photo Credit: Daniel Schlaepfer

Dr. Daniel Schlaepfer is the Fellow for the Global Drylands Working Group. Daniel completed his undergraduate through Ph.D. degrees in Switzerland and is now doing postdoctoral research at the University of Wyoming. He studies the ecosystem response to climate change, human disturbances, and land use. As part of the Global Drylands Working Group he hopes "to answer how ecohydrology of temperate drylands affects ecosystem processes and composition of plant functional groups. Drylands are very limited by their water availability and are very sensitive to any change in hydrology; yet a large population of the world relies on these ecosystems. It is an interesting conflict of sensitivity and dependence, and it is crucial for us to understand how global changes are influencing these regions." Daniel adds that, "Collectively, we were able to increase our understanding of temperate dryland regions in response to global change, land use changes, invasive species, and climate change. We were also able to share research questions and objectives. It was amazing to see the wealth of in-depth questions and creative approaches I could not have come up with alone."

Dr. Elise Zipkin is the Fellow for the Bayesian Models of Population Persistence Working Group. After earning her bachelor’s degree from the University of Michigan in mathematics and resource ecology in 2003, she went on to receive her master’s from Cornell University in natural resources in 2008. This year, she completed her Ph.D. in biology at the University of Maryland. With a background in research at the interface of applied ecology and methods, Elise focuses on quantitative ecology and is interested in population and community dynamics, control of nuisance and invasive species, and estimating species occurrence and detection. In addition to her fellowship with the Powell Center, she currently has a post-doctoral position at the USGS Patuxent Wildlife Research Center. Elise finds her fellowship and the Working Group process to be an invaluable and unique process: "The platform the Working Group provides for coming together to intensively focus on a large-scale problem is great. We can exponentially move science forward by finding the most optimal ways to develop the thinking process." Elise finds Bayesian modeling interesting because "the ability to combine different datasets is going to allow for bigger questions to be answered on larger spatial scales rather than what you would find working with one dataset alone."

Dr. Isabella Mariotto, the Fellow for the Global Croplands Working Group, is also a research scientist for the USGS at the University of Arizona in Flagstaff. She studied at the University of Padova, Italy, and earned her M.S. and Ph.D. in ecology and evolutionary biology with an emphasis on GIS and remote sensing from New Mexico State University. In addition to her Powell Fellowship, she is working on a NASA project using hyperspectral and multispectral satellite data to determine crop productivity in Central Asia. Isabella finds the topic of global croplands and food security important "because sharing information among experts around the world through the Powell Center will facilitate the development of a global system, consistent across nations and regions, which can help optimize crop production and water use." She had a paper published on specialized topics related to GIS (Mariotto, Gutschick, and Clason, 2011) and was recently honored by receiving a 2012 ESRI award for Best Scientific Paper in GIS (second place).

Photo of Ruscena Wiederholt
Ruscena Wiederholt
Photo Credit: Franklin Egan

Dr. Ruscena Wiederholt is the Powell Center Fellow for the Animal Migration and Spatial Subsidies Working Group. Ruscena supports modeling efforts and cross-group coordination of the evaluation of Mexican free-tailed bats, Pintail Ducks, and monarch butterflies that migrate between Mexico and the United States. She was previously a postdoctoral researcher at the USGS Patuxent Wildlife Research Center, where she studied the effects of climate change on amphibian populations. She has a B.A. from the University of California, Berkeley; an M.S. from Pierre and Marie University in Paris; and a Ph.D. in ecology from Pennsylvania State University. Her main ecological interests are in conservation biology and the provision of ecosystem services. She believes the valuation and identification of ecosystem services provides a novel and valuable approach for species conservation. Ruscena wants to learn more about ecosystem service research, its policy applications, and the method of collaborative research promoted by the Powell Center. She hopes the results of the effort will aid in trans-boundary conservation efforts. As for the type of interdisciplinary research within the Working Group fostered by the Powell Center, "It’s been a very interesting and unique experience to work with scientists from a variety of backgrounds (biology, statistics, economics, wildlife ecology, ecology). Usually you don't have the luxury of having such a range of expertise at your fingertips. It really improves our work and helps us progress more quickly than we could otherwise," she says. Ruscena would like to continue conservation-focused ecological research in the future. Her current focus is working on migratory network modeling and calculating ecosystem service values for Mexican free-tailed bats at the University of Arizona in Tucson in the School of Natural Resources and the Environment.

Not all of the Fellows at the Powell Center are postdoctoral.

Tom Blitz, the Fellow for the Erionite and Human Health Working Group, is working toward his undergraduate degree in geophysical engineering at the Colorado School of Mines. His particular interest in remote sensing capabilities led him to an apprenticeship with USGS Geologist Greg Meeker. Tom says, "I think that the process is fairly unique, with the approach of combining earth and health sciences being something that we should use more often. I see the results that come from the working group becoming quite valuable as the combination of health and geology will yield a much more comprehensive and complete project than either science alone." Tom is grateful for the opportunity to see how problems can be solved by an interdisciplinary group that combines many different points of view to work toward a comprehensive solution.

Photo of Alexander Jonesi
Alexander Jonesi
Photo Credit: Lorie Hughes

Alexander Jonesi is a student intern also participating in the Erionite and Human Health Working Group . He is currently working toward an undergraduate degree at the University of Maryland in College Park, majoring in environmental science and policy with a concentration on policy and politics. Alexander says, "The Center pulls together different groups of people to collaborate at a single location as opposed to playing email or phone tag. Left alone, each group might publish something that does not include important information, so the collaboration is extremely important. Also, the group activities and dinners really brought everyone together and made the atmosphere friendlier and easier to work in." Alexander finds the topic of erionite and human health exciting because he is highly interested in policy: "Lawmakers cannot make policy without the health data." He hopes to increase his knowledge of human health so that he can better understand how policy is developed.

Visit the current projects section of our Web site at to learn more about these projects.

Reference Cited

  • Mariotto, Isabella, Gutschick, V.P., and Clason, D.L., 2011, Mapping Evapotranspiration from ASTER Data through GIS Spatial Integration of Vegetation and Terrain Features: Photogrammetric Engineering & Remote Sensing, v. 77, no. 5, p. 483–493.