Principal Investigators

Lawrence Baker, Ph.D.- Research Professor

Department of Bioproducts and Biosystems Engineering

Lawrence Baker

Larry Baker entered the realm of urban ecosystems in 1997, as part of the team that formed the Central Arizona-Phoenix Long-Term Ecological Research program, one of the first of two "urban ecosystems" (the other was Baltimore).

The broad goal of his research is to develop novel approaches for reducing pollution that are more effective, cheaper and fairer than conventional approaches. His "early UE" phase included development of the first detailed urban nitrogen cycle, an analysis of ecological effects of the urban heat island, and a study of adaptive management to improve the quality of municipal drinking water.

In addition to TCHEP, his recent research has included the development of a whole-watershed P balance tool to guide P reduction strategies, the development of salt balances for five western cities to guide water softener bans, and a study of P removal from streets by street sweeping. A major recently completed project has been editing a book, Water Environment of Cities (2009), now available in many university libraries as an "e-book".

In the past few years, he has started writing for practitioner magazines (such as LakeLine, Stormwater, and Southwest Hydrology) and public audiences (such as the Minnesota Journal and the Minneapolis Star and Tribune) and is a frequent public speaker at venues from Audubon Club meetings to "Policy and Pint" events.

Outside work, he is chair of a citizen watershed group, Friends of the Sunrise River, which is fighting construction of a power plant, and has been very active in the Citizens League, a unique Minnesota organization that seeks better governance. A geek by nature, he reads Foreign Affairs for relaxation, but is also an avid Boundary Waters canoer, cyclist, and volleyball player.

Sarah Hobbie, Ph.D. - Associate Professor

Department of Ecology, Evolution and Behavior

Sarah Hobbie

Sarah Hobbie's research focuses on two main areas: 1) the influence of changes in atmospheric composition, climate, land use, and plant species composition on ecosystem processes, and 2) the effects of urbanization on biogeochemical cycles. In the area of global change, she is conducting research aimed at understanding how atmospheric nitrogen inputs affect decomposition; how variation in biodiversity, atmospheric carbon dioxide, nitrogen inputs, and precipitation influence grassland ecosystems; and how warming influences the establishment of boreal and temperate trees at the southern boreal-temperate forest ecotone. In the area of socioecological effects of urbanization, she is collaborating with engineers and social scientists to understand how human choices influence the cycling of elements through households in the Twin Cities, Minnesota, as well as the factors that influence household decisions relevant to biogeochemical cycling.

Professor Hobbie is active in the National Science Foundation Long-Term Ecological Research program, with ongoing research at the Cedar Creek Ecosystem Science Reserve. She also serves on the LTER Executive Board. She is an Aldo Leopold Fellow and has served on the National Center for Ecological Analysis and Synthesis Center's Science Advisory Board and on several NSF panels. Most recently, she has contributed to a report for the Minnesota State Legislature evaluating the potential for Minnesota's terrestrial ecosystems to sequester carbon, and thus offset emissions from fossil fuel combustion.

Jennifer King, Ph.D.- Associate Professor

Department of Geography, University of California, Santa Barbara

Jennifer King

Jennifer King's research field is biogeochemistry. Her research focuses on understanding what controls the cycling of elements through the Earth system. The overall goal of her work is to advance understanding of regional and global biogeochemical cycles and ecosystem processes. This knowledge can be used for developing predictive models and sound, strategic environmental policy.

Professor King's research focuses on processes occurring in the soil-plant-atmosphere system. She conducts her research in both natural ecosystems and human-dominated ecosystems. She is especially interested in studying interactions of physical and biological factors that influence spatial and temporal variability in biogeochemical processes. For example, one current research area is photodegradation - the decomposition of plant litter through solar radiation. Although decomposition is predominantly a biological process, mediated by microorganisms, we have found that photodegradation, an abiotic process, contributes significantly to the decomposition process in arid ecosystems. The varying biotic and abiotic controls on decomposition have important consequences for biogeochemical cycling of carbon and nutrients.

Since she rarely takes her "biogeochemistry lenses" off, studying the biogeochemistry of urban ecosystems was a natural step! As a TCHEP investigator, Professor King is interested in exploring the primary controls on household fluxes and the relationships among measured variables. She is part of a group that is examining variability among household landscape components (lawn, soil, trees). Examining the sources of variability in biogeochemical fluxes through Twin Cities households will provide insight into the factors that influence element cycling.

Joe McFadden, Ph.D.- Assistant Professor

Department of Geography, University of California, Santa Barbara

Joe McFadden

 Joe McFadden's research is focused on interactions between ecosystems and the atmosphere, particularly in places where land-use and land-cover change are happening over large regions.

Professor McFadden's urban research aims to improve our understanding of how vegetation affects the climate, atmospheric composition, and water cycle in cities and suburbs, and how this knowledge can be used to improve urban design. In addition to TCHEP, he was the Principal Investigator of a NASA-funded urban carbon, water, and energy flux study at the KUOM tall tower in Minneapolis-Saint Paul from 2005-2009. This project is a component of the U.S. interagency North American Carbon Program.

Currently, he is a Co-PI on a National Science Foundation sponsored Urban Long-Term Environmental Research Exploratory (ULTRA-Ex) project focused on vegetation, water, and ecosystem services in Los Angeles. His work is interdisciplinary, and he has served on review panels in four different National Science Foundation programs and two NASA programs. He was awarded a NASA New Investigator Award in 2004.

Kristen C. Nelson, Ph.D. - Professor

Department of Forest Resources and Department of Fisheries, Wildlife and Conservation Biology

Kristen Nelson

Kristen C. Nelson is an environmental sociologist, whose research contributes to the interdisciplinary understanding of environmental change and its dynamic with human systems. Her urban ecosystems research focuses on what influences homeowner decisions (attitudes, norms, perceived control, sociodemographic factors), how behaviors influence biogeochemistry/environmental services, and social change in complex systems (social networks). She does much of her work in collaboration with foresters, ecologists, entomologists, and engineers. Beyond urban ecosystems, her recent research focuses on social science aspects of deliberative governance and policy formation, environmental risk assessment, sustainable development, social networks in multi-functional agriculture, and negotiating the public/private interface of wildfire preparedness; the research agenda emphasizes theoretical and practical insights regarding what influences human behavior and societal change at multiple scales.

At the University of Minnesota, Professor Nelson is a Morse Distinguished Faculty member, Major Co-Coordinator for Environmental Science, Policy, and Management and a Professor in the Department of Forest Resources and the Department of Fisheries, Wildlife and Conservation Biology. She received her M.S. and Ph.D. from the School of the Environmental and Natural Resources at the University of Michigan-Ann Arbor. She has worked with international colleagues in Kenya, Brazil and Vietnam on designing governance and risk assessment methodologies for GMOs as well as for nanotechnologies in the US. Her previous projects focus on sustainable development and conservation include carbon sequestration and organic coffee in Chiapas, Mexico and knowledge production for integrated pest management in Nicaragua.