Controls on N Fixation
Once an N fixer establishes at a site, the amount of N that it brings into the ecosystem is determined by its individual fixation rates. We use a combination of greenhouse experiments and field sampling to assess the physiological constraints and competitive advantage or disadvantage of N fixation in different environmental conditions. Specifically, we focus on how light and soil-nitrogen availability regulate N fixation rates, and if these effects differ in the presence of competing plants.