Biology

I am an aquatic ecologist with a strong interest in links between ecosystem processes and community interactions, and how these are affected by natural landscapes. I am particularly interested in how resource fluxes affect organisms' interactions, and conversely, how species traits and interactions affect pathways of nutrient and carbon cycling. My graduate research focused on how the ecological role of caddisfly grazers varied with watershed landscape position. I identified stream size thresholds associated with changes in grazing regimes. My findings also suggested that traits of primary consumers have consequences for whether algal energy is transferred up the food web to predators, or sequestered in predator-defended herbivores.

Currently I am collaborating with researchers from the University of California, University of Minnesota, and Simon Frasier University on projects linking stream community and ecosystem processes to the landscape of a northern California watershed. Projects include 1) measuring nutrient regeneration by dominant invertebrates, 2) determining landscape controls on stream primary productivity and terrestrial carbon inputs, 3) using stable isotopes and diet analysis to compare how energy moves through food webs in productive and unproductive streams.

I have also become interested in using measurements of basic ecosystem processes, such as primary productivity and nutrient cycling, as tools to evaluate stream ecosystem health. Anthropogenic impacts to streams are often assessed through labor-intensive biological monitoring based on invertebrate or algal communities. Measurements of ecosystem processes may be cheaper and less labor-intensive, and provide more insight into functional changes that may have occurred. However, their application to biological assessment has not been well-tested. I have begun some preliminary work comparing measures of nutrient uptake to conventional biological assessment using invertebrates, which I hope to expand