Anne Kraepiel, of Princeton University, visited the SSHCZO last week to begin a laboratory incubation experiment measuring nitrogen fixation rates in the watershed. Tree leaves were collected from three sites on the valley floor and incubated with four different nutrient treatments. Results from the experiment will be used to calculate rates of bacterial nitrogen fixation. Future work will include measurements of Mo concentrations to better understand the role Mo and other metals, such as V and Fe, play in the biogeochemical cycling of N in temperate forest ecosystems.