Research and Teaching Interests
I’m interested in how organisms both respond to, and in turn modify, their environments. At present I am pursuing two areas of research.
In the subarctic, terrestrial plant communities are dominated by slow growing, stress tolerant plants. We are investigating how the traits of theses plants suppress nutrient cycling, and therefore restrict overall ecosystem productivity and the expansion of the treeline. We are also investigating how carnivore activity can create nutrient hotspots, counteracting the effects of the plants, and create a positive feedback in the consumer food web.
My second area of interest is the ecology of nitrogen fixation. Nitrogen is the limiting nutrient for productivity in many regions of the world. While symbiotic nitrogen fixation removes this limitation, nitrogen-fixing plants are uncommon in many nitrogen limited habitats. We investigate the causes of this paradox by examining factors that limit the effectiveness of the nitrogen-fixing symbiosis. We also examine the contribution of non symbiotic nitrogen fixing associations to terrestrial ecosystems.