How do we apply the methods of biogeochemistry and ecosystem ecology to wetlands?
Stephen K. Hamilton

Associate Professor, Zoology; Kellogg Biological Station

   Biogeochemistry, Aquatic Ecology
 

My principal research interests involve biogeochemistry and ecosystem ecology, and particularly the investigation of ecological problems through the application of geochemical techniques, such as stable isotope analysis. I find running waters, wetlands and floodplains to be especially interesting ecosystems to study because they represent an interface between aquatic and terrestrial ecosystems that is often biologically diverse and productive. I believe that to understand how ecosystems function, we must integrate approaches from varied disciplines such as geology, chemistry, and hydrology as well as ecology. The problems associated with global change are particularly challenging in this regard.

Much of my research to date has focused on South American rivers and floodplains, and I have had the opportunity to work on diverse topics in several river systems. Most recently, I have been working in the Pantanal wetland of Brazil.

I have recently begun research on local wetlands and streams. I received funding from NSF’s Career Development Program to study the abundant and diverse wetlands in the glacial landscape around KBS. This 5-year research program will examine how the hydrology of the wetlands controls their biogeochemical and ecological characteristics, and how hydrological changes resulting from our changing climate may alter these ecosytems. In another project, I am part of a coordinated intersite comparison involving ten streams throughout North America, also funded by NSF. The idea is to enrich the 15N content of the inorganic N in stream water, and then trace the flow of this 15N through abiotic and biotic pathways, including food webs.

  

Selected Publications

Hamilton, S.K., W.M. Lewis, Jr. and S.J. Sippel. 1992. Energy sources for aquatic animals on the Orinoco River floodplain: Evidence from stable isotopes. Oecologia 89:324-330

Hamilton, S.K., S.J. Sippel and J.M. Melack. 1995. Oxygen depletion and carbon dioxide and methane production in waters of the Pantanal wetland of Brazil. Biogeochemistry 30(2):115-141.

Hamilton, S.K., S.J. Sippel and J.M. Melack. 1996. Inundation patterns in the Pantanal wetland of South America determined from passive microwave remote sensing. Archiv für Hydrobiologie 137(1):1-23.

Hamilton, S.K., S.J. Sippel, D.F. Calheiros and J.M. Melack. 1997. An anoxic event and other biogeochemical effects of the Pantanal wetland on the Paraguay River.  Limnol. and Oceanogr. 42:257-272