Upper Midwest Environmental Sciences Center

Biological production represents the total amount of living material (biomass) that was produced during a defined period of time. This production is important because some of it is used for food and some is valued for recreation, it is a direct measure of total ecosystem processes, and it sustains biological diversity. Production is a measure of energy flow, and is therefore a natural currency for ecosystems. Therefore, a sound understanding of biological production is essential to the effective science-based management of ecosystems.

Large river systems are biologically productive and support large numbers of species of plants and animals. Large-river ecosystems may be the most productive of aquatic ecosystems, and several broad scientific concepts ¹ have been advanced to explain that production.

These concepts qualitatively describe the general ways that nutrients and energy may be converted to biological production, but they do not tell us specifically how large-river ecosystems actually function. These general descriptive concepts are also largely untested. Science-based management of large rivers will require a better understanding of how these systems function, including the various ways that biological production pathways can be managed to preserve and enhance the value of these ecosystems to society.

Biological production is valued by society for both consumptive and nonconsumptive uses. Fish production in rivers supports commercial and economically valuable recreational fishing. The floodplains of large rivers are migratory corridors and nesting habitat for songbirds and waterfowl. These birds are prized both by birdwatchers and waterfowl hunters. The shells of unionid mussels of large North American rivers were once used to make buttons and are now highly valued for the manufacture of blanks used by the pearl-culture industry.

This research initiative seeks to understand the processes that affect biological production in large rivers to enable resource managers to preserve and enhance that production. This project uses a variety of approaches including analyses of existing data (such as the Long Term Resource Monitoring database for the Upper Mississippi River) and field studies using the unique capabilities of the Upper Midwest Environmental Sciences Center. Key subprojects include the following: a study of the effects of midsummer water-level drawdowns on the production of aquatic plants, the importance of off-channel areas to fish production, and the importance of deep channels to the production of riverine fishes.

This project is scheduled for completion in September 2007.

For more information, see these publications:

¹Johnson, B. L., W. B. Richardson, and T. J. Naimo. 1995. Past, present, and future concepts in large river ecology. Bioscience 43:134-141.

Dettmers, J. M., S. Gutreuter, D. H. Wahl, and D. A. Soluk. 2001. Patterns in abundance of fishes in main channels of the Upper Mississippi River System. Canadian Journal of Fisheries and Aquatic Sciences 58:933-942.