RUI: Collaborative Research: Nitrogen fixers in a western river network: constraints and consequences

St. Catherine University, Saint Paul MN

Investigators

Abstract

Biological nitrogen fixation is the process through which organisms convert nitrogen gas in the atmosphere to a form that can be used in other biological processes. Because biologically available nitrogen often limits plant growth, nitrogen fixation is a critical process that can influence ecosystem productivity, species composition, and food web interactions. The importance of nitrogen fixation has been studied in many terrestrial ecosystems, however this process has been relatively little studied in streams, which have often been thought to be limited by the availability of phosphorus rather than nitrogen. Topography, stream flow, and species composition and interactions will be examined as potential factors that limit nitrogen fixation in stream networks in the western United States; high resolution digital elevation data will be tested as a source of topographic information for these analyses. The results of this work, in combination with parallel efforts linking light and hydraulic regimes to digital topographic models, will facilitate the development of predictive maps that place the controls and consequences of biological nitrogen fixation into the physical and rapidly changing environmental context of river networks. Research opportunities and training will be provided to science and science education undergraduate students at the lead liberal arts institution, a women's college, by combining the liberal arts learning environment with access to the philosophies and lab facilities of large research groups. The opportunity to work with an interdisciplinary team of scientists will provide a diverse group of women first-hand experience in field ecology and the scientific process, encouraging many to pursue professional opportunities in science and science education.