|Stephen K. Hamilton|
Professor of Ecosystem Ecology & Biogeochemistry
Ph.D. University of California, Santa Barbara 1994
Phone: (269) 671-2231
My principal research interests involve ecosystem ecology and biogeochemistry, with particular attention to aquatic environments and the movement of water through landscapes. I am especially interested in running waters, wetlands and floodplains because they represent an interface between aquatic and terrestrial ecosystems that is often biologically diverse and productive. I also like to consider ecosystem processes at the landscape or watershed scale, and I prefer to do research that contributes to our understanding of environmental problems or improves our ability to manage ecosystems.
I believe that to understand how ecosystems work, we frequently need to integrate approaches from varied disciplines such as geology, chemistry, remote sensing, and hydrology as well as ecology. Therefore I encourage multidisciplinary investigations that seek to improve our understanding of ecosystems and environmental problems. Stable isotopes are one of my favorite tools for ecological investigations.
I am presently devoting much of my time to the study of various aspects of aquatic ecosystems in southern Michigan, including wetlands, streams, lakes, and watersheds. I also work on tropical ecosystems in South America and dryland river ecosystems in Australia.Grad students and postdocs
I presently advise four doctoral students: Dustin Kincaid, Bonnie McGill, Jorge Celi, and Micaleila Desotelle. In addition, I work closely with several postdocs associated with KBS research projects.
Detailed descriptions of my research projects:
Nitrogen cycling in streams
We have performed several whole-stream isotopic enrichment experiments to study nitrogen cycling and food webs in Michigan streams as part of an intersite comparison involving biomes throughout North America, known as the Lotic Intersite Nitrogen Experiment (LINX). The original LINX experiments were done in 1997-98 and focused on food webs. A second generation of studies in 2002-2006 examined how human disturbances affect nitrate uptake and retention in streams. I have worked together with Dr. Jennifer Tank and her team from the University of Notre Dame on sites throughout the Kalamazoo River watershed.
Michigan wetland ecology & biogeochemistry
I have an ongoing research program that examines how the hydrology of southern Michigan wetlands controls their biogeochemical and ecological characteristics, and how hydrological changes resulting from our changing climate may alter these ecosystems. A CAREER grant from NSF launched me into this research area. The area around KBS is excellent for comparative studies of wetlands because of the great diversity of these ecosystems. We have a large database of comprehensive hydrochemical variables in wetland waters that we are currently analyzing.
We became interested in alternative nitrogen uptake processes, and my former PhD student Amy Burgin spearheaded our research on these processes in wetlands and streams. Another PhD student, Lauren Kinsman, tackled the biogeochemistry of sediment phosphorus release in lakes and wetlands, funded by NSF. Related to this work and to the LINX project was an investigation of biogeochemical processes in wetlands that experience hydrological through-flow, such as impoundments along stream courses, led by my postdoc Jon O'Brien, who is now at the University of Canterbury in New Zealand.
Zebra mussel invasions of Michigan lakes
I am working with Dr. Orlando Sarnelle of MSU's Dept. of Fisheries and Wildlife and others to study the ecological impacts of zebra mussels, an exotic species presently spreading into our inland lakes. We are particularly interested in the possible link between the mussels and the recent occurrence of noxious blue-green algal blooms in lakes that were formerly considered to be oligotrophic (i.e., low potential for algal production). This research has included several experiments in large mesocosms, as well as surveys of lakes with and without the mussels, and has been funded by the National Sea Grant Program, the Kalamazoo Foundation, and the U.S. EPA through the Ecology of Harmful Algal Blooms program.
Kalamazoo River ecology
KBS lies in the watershed of the Kalamazoo River. One of my Master's students (Nicole Reid) studied the biogeochemistry of the river's reservoirs in the context of nutrient loading and eutrophication. Currently, my PhD student Leila Desotelle is investigating how algal growth in the reservoirs subsidizes downstream food webs. In addition, she is investigating the ecological ramifications of a major oil spill into the river in summer 2010, caused by a ruptured pipeline.
Since 1998 I have been one of the principal investigators on the Long-Term Ecological Research project at Kellogg Biological Station, which focuses on agricultural ecology. My role is to apply a watershed approach to understand how land use, including agriculture and other uses, impacts the quality of surface and subsurface waters in our region. A major new research initiative at MSU and KBS is the DOE-funded Great Lakes Bioenergy Research Center. At KBS we are investigating the environmental sustainability of proposed biofuel crops, ranging from conventional corn through grass monocultures and prairie polycultures and even tree plantations. I am leading the biogeochemical and hydrological aspects of this work, together with Phil Robertson.
Tropical rivers & floodplains
Much of my previous research has focused on South American rivers and floodplains, and I have had the opportunity to work on diverse topics in several river systems. During the 1990's, I worked in the Pantanal wetland of Brazil in collaboration with the Brazilian Center for Agricultural Research in the Pantanal. My research in the Pantanal has examined the biogeochemistry of wetland waters, methane production, floodplain hydrology, and remote sensing of inundation. Suzanne Sippel and I extended our work with passive microwave remote sensing to examine inundation patterns in all of the major floodplains of the continent, and in 2002 we published a synthesis paper on this work. Three Brazilian PhD students have spent several months working with me on data analysis and interpretation.
In 2002 I spent my sabbatical leave at Griffith University in Queensland, Australia, working with Dr. Stuart Bunn on dryland river ecosystems. We conducted a hydrological investigation of "waterholes" (deeper channel segments with permanent water) of the Cooper Creek system, in which we determined the relative importance of river flooding and local groundwater inputs.I have since been involved in science planning for rivers and watersheds of the tropical north. In 2008-2009 I returned for another year on sabbatical in Australia, working on tropical rivers and wetlands, with sponsorship from the Australian government in the form of a Commonwealth Environmental Research Fellowship.
For several years we have had a research project on the Napo River in Peru and Ecuador, led by my PhD student Jorge Celi. Our goal is to improve our understanding of the hydrological connectivity between the river and its vast fringing wetlands and floodplains. This is critically needed information because there are proposals for developing the Napo River into a major waterway for industrial barge transport, which would entail alterations such as dredging and perhaps straightening the channel. Thus we need to be able to estimate the impacts of such projects on the biodiversity and ecosystem services in adjacent environments, which are known to be one of the world's hotspots of biodiversity.
Our research on water resources also results in numerous opportunities for community outreach and involvement in local environmental issues. I serve as President of the Kalamazoo River Watershed Council and regularly contribute information to local governments, regulatory agencies, NGOs, and the media. Since the July 2010 oil spill in the Kalamazoo River, I have provided advice to the EPA and the pipeline company, and I have given numerous media interviews and several public talks on the spill and its ecological impacts. Examples of recent media coverage include:
Former graduate students and their whereabouts:
|Last Updated on Tuesday, 13 August 2013 01:27|