Charlie Warren is an Assoc Prof in the School of Life and Environmental Sciences at The University of Sydney. Charlie's research examines how plants interact with their biotic and abiotic environment. The scope of this research includes the chemical and physical processes associated with life (e.g. photosynthesis, respiration, gas exchange, nutrient uptake). Examples of research projects include: • Competition for nitrogen between plants, bacteria and fungi • Interactions between plants and soil • Soil processes at cold temperatures (e.g. under snow) These biological questions are addressed using a raft of analytical techniques such as: • Isotope labelling and laser absorption spectrometry • Analytical separations and mass spectrometry based metabolomics