SGER: Undergraduate Research in Biogeochemistry: Controls Over the Isotopic Composition of Nitrous Oxide

Northern Arizona University, Flagstaff AZ

Investigators

Abstract

Better known as laughing gas, nitrous oxide (N2O) is also an extremely important greenhouse gas, contributing to global warming. Soil nitrogen transformations that lead to production of N2O are extremely dynamic after wildfire in forest ecosystems. This project will examine these dynamics using a recent wildfire near Flagstaff, Arizona. Two distinct groups of bacteria produce N2O in soils. Because these bacteria are sensitive to different environmental conditions, understanding their relative contributions to N2O production is important in predicting future N2O fluxes. Stable isotopes of nitrogen and oxygen in N2O have been proposed as signatures of the particular microbial processes responsible for N2O production, but this idea has never been explicitly tested in the field. This work will involve undergraduate students in research using the natural dynamics of N2O production after fire to test to what extent these isotopic 'fingerprints' reliably indicate the bacterial groups producing N2O evolved from soil.