Coupled Biogeochemical Cycles in Human Ecosystems

Project Staff

Principal Investigators: Lawrence A. Baker, Senior Fellow, Water Resources Center and Patrick L. Brezonik, Professor, Department of Civil Engineering

Additional Staff: Dave Mulla, Professor, Soil, Water, and Climate; Robert Sterner, Professor, Ecology, Evolution, and Behavior; and Heinz Stefan, Professor, Department of Civil Engineering; Marvin Bauer, Professor, Forest Resources, University of Minnesota


National Science Foundation

Project Duration

September 2001 - August 2006


Human ecosystems—the cities where most of us live and the farms that sustain us—cover a small fraction of the Earth’s surface, but are sites of intensive biogeochemical activity. One consequence of this intensification is that pollution of major elements remains widespread. Despite this, very little is known about biogeochemical cycles of human ecosystems. Developing an ecosystem framework for understanding biogeochemical cycles in human ecosystems holds promise for revealing new approaches for pollution control. We can reasonably postulate that pollution control strategies developed with an ecosystem framework will be cheaper, more effective, and fairer than current policies, which were often developed reflexively. The goal of this project is to develop a conceptual framework for studying human ecosystems. This is being done through a series of workshops with researchers from the University of Minnesota and Arizona State University. The conceptual framework that has evolved is based on four “couples”: stoichiometric coupling; coupling between elements and hydrology; spatial couples at various scales; and coupling between elemental cycles and sociocultural processes. The workshop groups also have developed an approach for embarking on regional-scale studies of human ecosystems. A key component of this development is the identification of information databases and types of satellite imagery that were available for studying biogeochemical cycles in cities and agricultural areas.