The environmental conditions that support life on Earth arise from a complex interactive web of chemical, biological, and physical processes. As a biogeochemist, I study how these processes affect elements as they flow through ecosystems. Knowledge of fundamental biogeochemical cycles and how they respond to perturbations is essential for understanding how human activity is affecting climate and air, water and soil quality.
I am particularly interested in the biogeochemical cycles of iodine, carbon, and trace metals. I use a wide range of analytical techniques to measure concentrations and chemical forms of these elements in air and water, and study how they are modified by plants, algae and other microorganisms. A long running theme is the role phytoplankton and macroalgae play in controlling iodine speciation in the ocean. This is important because certain forms of iodine (iodide, I-) remove ozone, a pollutant gas, from the lower atmosphere through reactions at the sea surface. I am also interested in the composition of dissolved organic carbon. Detailed molecular fingerprints are obtained using high resolution mass spectrometry, and features with potential to affect air quality and climate identified.
Recently, I have expanded my research interests to include biogeochemical processes in designed landscapes and horticultural situations, and am currently examining the impact of urban green infrastructure such as living walls on air and water quality, in a project supported by the York Environmental Sustainability Institute.