IGERT Faculty

PI: Claudia Neuhauser, Dept. of Ecology, Evolution and Behavior

Co-PIs:
Christopher Paola, Dept. of Geology and Director of the NCED
Raymond M. Hozalski, Dept. of Civil Engineering
Shinya Sugita, Dept. of Ecology, Evolution and Behavior
Miki Hondzo, Dept. of Civil Engineering and NCED

Senior Personnel:
William A. Arnold, Dept. of Civil Engineering
James B. Cotner, Dept. of Ecology, Evolution and Behavior
Jacques C. Finlay, Dept. of Ecology, Evolution and Behavior and NCED
Efi Foufoula-Georgiou, Dept. of Civil Engineering, co-Director of NCED
Sarah E. Hobbie, Dept. of Ecology, Evolution and Behavior
Nihar Jindal, Dept. of Electrical and Computer Engineering
Jennifer Y. King, Dept. of Soil, Water and Climate
Timothy M. LaPara, Dept. of Civil Engineering
Joseph P. McFadden, Dept. of Ecology, Evolution and Behavior
Paige J. Novak, Dept. of Civil Engineering
Stephen Polasky, Dept. of Applied Economics
Fernando Porté-Agel, Dept. of Civil Engineering and NCED
Shashi Shekhar, Dept. of Computer Science and Engineering
Robert W. Sterner, Dept. of Ecology, Evolution and Behavior

Non-Senior Personnel:
Tim Griffis, Soil, Water and Climate
Tian He, Computer Science and Engineering
David Levinson, Dept. of Civil Engineering
Lesley Perg, Department of Geology
Michael Sadowsky, Soil, Water and Climate
Peter B. Reich, Dept. of Forest Resources
G. David Tilman, Dept. of Ecology, Evolution and Behavior
Sangwon Suh, Biobased Products
Vaughan R. Voller, Dept. of Civil Engineering, co-Director of NCED
Naomi Zeitouni, Department of Applied Economics

Faculty Research Interests

Claudia Neuhauser

Dr. Neuhauser’s research is at the interface of ecology and evolution. Trained as an applied probabilist, most of her research has dealt with theoretical and abstract aspects of population and community dynamics. Over the past few years, her research has expanded into more applied areas and she has become particularly interested in developing theoretical frameworks for networks at different scales, from metabolic networks to networks at the community or ecosystem level. Currently, she is exploring host-symbiont dynamics in managed and natural habitats and aquatic food web models. She is also quite interested in transferring current research into the classroom, either through development of teaching modules or short presentations that demonstrate how class material is used in current research. Web | neuha001@umn.edu

Christopher Paola

My research focuses on the long-term evolution of depositional river systems and how these are recorded stratigraphically. My current specific interests include interaction of braided rivers and vegetation, modeling the long-term coevolution of rivers and associated marine systems, and experimental stratigraphy using our subsiding-floor experimental basin. Web | cpaola@umn.edu

Raymond M. Hozalski

I am interested in the sources, fate, and transport of natural organic matter (NOM) and other “pollutants” in surface waters and the effects of these pollutants on water quality and water treatment. NOM can foul ultrafiltration membranes, increase water treatment chemical dosage requirements, react with chlorine to form potentially harmful disinfection byproducts, and serve as a food source for bacteria in the treatment works and in distribution systems. The watershed also contributes suspended solids, pathogens, and synthetic organic and inorganic chemicals to the raw water intakes. The overall goal of this line of research is to correlate pollutant (e.g., NOM) loadings with land use in order to predict the effects of land use change on drinking water treatment operations and tap water quality. Ultimately, this could lead to enhancements in watershed management that lead to improved raw water quality, reduced water treatment costs, and better quality tap water. Including the watershed as part of the water treatment operations represents a paradigm shift in approach and suggests transferring the burden, where appropriate, onto the polluter (i.e. polluter pays philosopy). Web | hozal001@umn.edu

Shinya Sugita

I am interested in non-linear response of terrestrial vegetation to climate change and human impacts since the last glacial maximum 21,000 years ago. Using both fossil records and computer modeling, I have been studying range shifts of trees in the upper Great Lakes region, stand-scale dynamics of hemlock-hardwood forests in northern Michigan, and the impacts of human activities on vegetation and climate in northern Europe over the last 6-8000 years. My research approach includes applications of diffusion models for a better understanding of plant migration in fragmented landscapes, effects of species invasion and seed dispersal on spatial dynamics of vegetation, and fossil-pollen representation of vegetation in the past. Web | sugit001@umn.edu

Miki Hondzo

Our long-term goal is to develop an understanding of how environmental fluid dynamics affect the biochemical processes in lakes, rivers, and watersheds. We conduct laboratory and field measurements to quantify the interaction between small-scale fluid motion and freshwater aquatic organisms, including bacteria, suspended algae, zooplankton and periphyton. Turbulent fluid-flow conditions, characterized by energy dissipation levels, are integrated with biomass accrual, metabolic rate, mobility, thin layer formation, and nutrient uptake. The interactions are characterized in most cases by nonlinear and nonequilibrium functional dependencies, which require extensive measurements of spatial and temporal heterogeneities of dependent variables and drivers across the scales. Our research findings enable a mechanistic foundation towards formulating process-based models of autotrophy and heterotrophy in aquatic ecosystems. Web | mhondzo@umn.edu

William A. Arnold

Prof. Arnold’s interests are in the transport and reactions of organic contaminants in environmental systems. Research topics specifically relevant to the IGERT program are the photochemical fate of pharmaceutical compounds in rivers and the development of reactive membranes for contaminated river sediments. In each of these areas, we are interested in how the chemicals or the remediation technique affects stream function and ecology. Web | arnol032@umn.edu

James B. Cotner

I try to understand the role of heterotrophic bacteria in regulating production versus decomposition in aquatic environments. Because most organic carbon burial occurs in aquatic ecosystems, they are critical to carbon dynamics on Earth. Furthermore, because heterotrophic bacteria are the most numerous organisms on the planet, they play a critical role in carbon fluxes in lakes and the ocean. Most carbon passes through “the microbial loop” on the way to its ultimate fate, either as storage in sediments or respiration as carbon dioxide. The availability of inorganic nutrients, especially phosphorus (P), plays an important role in the regulation of carbon fluxes in aquatic ecosystems through its impact on bacteria. In the coastal ocean and eutrophic lakes (high P availability), relatively low quantities of primary production funnels through bacteria and the microbial loop, increasing nutrient and carbon availability to the remainder of the food web. This contrasts with most of the ocean and many oligotrophic (low P availability) lakes where bacteria, because of their high affinity for P, are the main biomass component and the most metabolically active part of the microbial loop. Consequently, if you would like to catch fish, you probably would not want to spend most of your time in the oligotrophic gyres of the open ocean or the middle of Lake Superior. Because of their critical metabolic function in the biosphere, bacteria have significant impacts on the geochemistry of soils, lakes, rivers and oceans, including cycling and food web dynamics of contaminants, such as mercury and PCBs.

I have examined microbial processes in a wide variety of habitats: pelagic and benthic, freshwater and marine, lotic and lentic, and natural and human-impacted systems. I am particularly interested in the impacts of humans on microbial functions in ecosystems. Web | cotne002@umn.edu

Jacques C. Finlay

I am broadly interested in the ecology of aquatic ecosystems, and their interaction with surrounding natural and human altered landscapes. My research is in the areas of limnology, biogeochemistry, and food web and ecosystem ecology. Current research projects include investigation of energy flow and nutrient cycling regulation in river food webs, impacts of introduced species on aquatic ecosystems, nitrogen cycling in Lake Superior , and carbon and nitrogen biogeochemistry of high latitude watersheds. A pervasive theme in much of this research is that both food webs and ecosystems interact across traditional boundaries of ecological investigation through fluxes of elements, organic matter, and organisms. I am interested in understanding the nature and controls of such interactions, and their role in regulating the productivity and structure of aquatic and terrestrial ecosystems. Web | jfinlay@umn.edu

Efi Foufoula-Georgiou

Research interests are in the area of stochastic modeling and multiscale dynamics of surface hydrologic and geomorphologic processes. Specific areas of research include stochastic modeling of space-time rainfall, rainfall estimation from remote sensors, geomorphologic study of river networks and hydrologic response, multiscale nonlinear interactions and dynamical systems. Web | efi@umn.edu

Tian He

My research interests lie broadly in wireless and sensor networking, distributed systems and real-time computing. Currently, my research is focusing on Wireless Sensor Networks (WSNs), a new information paradigm based on the collaboration of a large number of self-organized sensing nodes. These networks form the basis for many promising applications such as habitat monitoring, intelligent battlefields, hazard response systems, smart hospitals and learning environments. My research is mainly system-oriented - building practical systems. Specifically we are aiming at four major interleaved efforts: 1) Integrated sensor systems such as VigilNet, 2) sensor network middleware service such as localization, networking, and coverage. 3) in-situ sensor system modeling and enhancement, and 4) architecture, system, language and development support for large-scale integrated sensor network systems. The ultimate research goal is to contribute to the design, implementation, deployment, use and maintenance of practical sensor systems. Web | hexxx071@umn.edu

Sarah E. Hobbie

I am broadly interested in all areas of ecosystem ecology, and especially in the interface between plant community and ecosystem ecology. In particular, I am interested in how plant species effects on ecosystem processes compare in magnitude to other factors that influence these processes.

Because one of the primary ways that plant species influence ecosystem processes is through their differential effects on litter decomposition and nutrient cycling, I have become interested in basic questions regarding the regulation of decomposition of plant litter. For example, I am interested in whether the same nutrients that limit plant growth also limit rates of decomposition, and when and where decomposition is carbon- versus nutrient-limited.

I hope that through my research I can both increase our basic understanding of how ecosystems function, but also improve our ability to predict how global changes caused by human activity (for example, climate change and nitrogen deposition) will alter ecosystems. Web | shobbie@umn.edu

Nihar Jindal

Nihar Jindal’s research investigates the fundamental limits of wireless sensor networks, asking questions such as: How much power and bandwidth is required for every sensor to upload his measurements in a particular network? How can information/measurements be optimally processed (i.e. filtered, compressed) within the network to reduce the communication burden? This work primarily uses tools from information theory, which is the theoretical foundation of data communication. Web | nihar@umn.edu

Jennifer Y. King

Research in my lab focuses broadly on the impacts of environmental change (natural and human-induced) on the biogeochemical cycling of carbon and nutrients. One area of research is investigation of the influences of agricultural management practices (e.g., conventional farming, reduced tillage, organic farming) on nutrient cycling and losses. Organic farming, for example, is generally believed to improve soil quality and sustainability of agricultural land. However, organic farming requires higher investment of energy and perhaps greater transport of material to be successful, compared to conventional farming methods. Growing perennial crops is another land management practice that is being explored for potential as a source of bio-based fuel as well as a means to mitigate environmental impacts of intense land use. Another area of research is examination of the coupled movements of carbon, nitrogen, and phosphorus through urban environments. Urban ecosystems are heavily managed by human activities and influenced by human choices. The study of biogeochemical cycling of elements through urban systems will help to identify the components of highly engineered systems that have the greatest influence on fluxes of energy and materials. Web | jyking@umn.edu

Timothy M. LaPara

My research focuses on the microbial ecology of engineered and natural systems to reduce the environmental impact of pollution. Environmental engineers have historically used a “black box” approach to design and install pollution control strategies that utilize undefined, mixed bacterial communities to catalyze the breakdown of pollutants. The principal goal of my research, therefore, is to better understand the relationship between bacterial community structure and bacterial community function. Because “bacterial community function” is equivalent to process performance in engineered systems, my research can simultaneously make fundamental contributions to the fields of microbial ecology and environmental engineering. Web | lapar001@umn.edu

Joseph P. McFadden

Biosphere-Atmosphere Interactions: We seek to improve our understanding of the mechanisms by which natural and human-modified ecosystems both respond to and feed back on global environmental change. Our current research is focused on understanding how changes in vegetation structure affect climate processes and the cycling of carbon and water at regional scales. To do this, we study the ecological and physical processes that control fluxes of carbon, water, and energy between the biosphere and the atmosphere. We use a wide array of methods including ecophysiological measurements, micrometeorological techniques, numerical modeling, and remote sensing. An important focus of our work is to use these tools in combination to bridge the gap in scales between ecosystem and global studies. Our approach is interdisciplinary, borrowing concepts and tools from atmospheric science, biogeochemistry, environmental physics, hydrology, and plant physiology to address large-scale ecological questions. Web | mcfadden@umn.edu

Paige J. Novak

I study how communities of microorganisms and overall community function changes as a result of environmental conditions, particularly within the context of hazardous waste degradation. Current areas of research include (1) how a biofilm’s cohesive energy density, which is related to strength, is altered as a result of environmental conditions, (2) the change in microbial communities and community function as a result of pollutant input or remedial action, and (3) the fate of estrogenic compounds throughout a wastewater treatment plant, where the environment can change drastically in terms of nutrient level and redox state. In each of these instances what occurs on a macroscopic scale affects the microscopic scale, and vice versa. In addition, non-linear drivers are active in the influence of microbial processes, which are themselves non-linear in nature. Web | novak010@umn.edu

Stephen Polasky

Web | polasky@umn.edu

Fernando Porté-Agel

Web | fporte@umn.edu

William Robbins

My research interests are in ultrasonics, sensors and actuators, and energy scavenging (generation of modest amounts of electrical power) from the ambient. A project to generate limited amounts of electricity from the wind using flexible piezoelectric materials flapping in the wind analogous to flags was started this year (2005). A study of surface acoustic wave delay lines coated with thin films of a new magnetostrictive material (gallium-iron) is currently being formulated. Such delay lines will have applications as magnetic field sensors and as novel signal processing devices such as real-time convolvers. Web | robbins@umn.edu

Shashi Shekhar

Shekhar’s current work relates to evacuation planning and spatial data mining. His group is developing capacity constrained routing algorithms to assist transportation security analysts to design effective evacuation routes and schedules as well to reconfigure transportation networks to maximize evacuation rate. His group is also developing techniques to analyze and mine spatial datasets. Spatial data mining problems are different from those in classical data mining. First, spatial data is embedded in a continuous space, whereas classical datasets are often discrete. Second, spatial patterns are often local where as classical data mining techniques often focus on global patterns. Finally, one of the common assumptions in classical statistical analysis is that data samples are independently generated. In contrast, spatial data tends to be highly auto-correlated. Main contributions made by our group to this area includes algorithms and data-structure that can scale up to massive (terabytes to petabytes) datasets as well as formalization of newer spatial patterns (e.g. colocations) which were not explored by other research communities due to computational complexity. Specific projects includes discovering spatial co-locations, detecting spatial outliers and location prediction. Web | shekhar@umn.edu

Robert W. Sterner

Web | stern007@umn.edu

David Levinson

Infrastructure, particularly transportation infrastructure, employs the network in both social and physical dimensions. My principal interest is to link the social and economic aspects of networks with the physical. Questions about the underlying cost structure, the financing mechanism, and the price charged for use cannot be divorced from the organization of the industry providing the service and the nature of supply and demand. These questions depend on the available technology, while the rate of technological change cannot be separated from the industrial organization and market conditions which spawns it.

Measuring the benefits of new infrastructure is essential for a comprehensive evaluation. Benefits from deploying new infrastructure in an area with little or no service may have far-ranging impacts involving restructuring the other aspects of industrial and human activity patterns. Benefits to users and non-users need to be identified and measured over a range of infrastructure deployment levels, from infant to mature systems. This has particular relevance for Intelligent Transportation Systems, which serve new markets and in many cases employ linked technological systems.

Benefit measures require an understanding of how networks emerge over time. The utility of a transport network depends on the number of users, while the number of users depends on its utility. The more connected a network the more valuable it is, and the less the average cost of the use of its fixed assets, recognizing that too much use relative to the network’s capacity creates congestion. For instance, there is a desire to deploy a new transportation technology such as advanced highways systems in the upcoming years. There remains the sticky chicken-and-egg problem, that unless there are widely deployed smart highways, few will buy advanced cars, and if there are no advanced cars, there will be no demand for smart highways. This underlying problem of critical mass is faced in every new network, from telecommunication and electricity to the historic transition in the highway system from animal powered vehicles and dirt roads to cars and paved roads. It is repeated in many locations, as networks grow from small nodes to become linked. Web | levin031@umn.edu

G. David Tilman

Ecological effects of human domination of the earth, including effects on ecosystem services of value to society; the ecological mechanisms controlling speciation, community assembly, species invasions and the evolution and maintenance of biodiversity; population ecology and theory of community dynamics and biodiversity; role of resource competition; biodiversity and ecosystem functioning; effects of habitat destruction. Web | tilman@umn.edu

Peter B. Reich

Web | Email

Vaughan R. Voller

Voller’s main research area is the development of numerical and computational techniques for handling so called free and moving boundary problems. This class of problems is defined by the requirement to locate of track a boundary between physical domains as part of the problem solution. The classic example is the tracking of the ice-water interface during the melting of ice. More natural based examples, and a focus of Voller’s current research efforts, include the tracking of shoreline in sedimentary basins, and species migration and dispersal. Web | volle001@umn.edu

Naomi Zeitouni

Naomi Zeitouni is at the Department of Applied Economics at the University of Minnesota. Her areas of specialty are environmental economics and water resource management. Her recent research projects include: understanding the effect of environmental damage on resource development timing and magnitude, optimal water extraction from a renewable groundwater aquifer with uncertain recharge, contingent valuation of coral reef degradation, and participation in an interdisciplinary research on regional effects of climate change.

Dr. Zeitouni majored in economics and statistics at Tel Aviv University and received her Ph.D. in economics from the university of Rhode Island. Before coming to the University of Minnesota in 2002, Dr. Zeitouni worked at the University of Haifa. Web | zeito001@umn.edu