1. AGU 2018 Session B092: Understanding the Biogeochemistry of Nitrogen Inputs and Outputs from Molecular to Global Scales

    Life requires nitrogen (N) as a primary nutrient. Nitrogen is found in abundance as nitrogen gas (N2) in Earth’s atmosphere but must undergo chemical changes that yield “fixed” N forms to be readily available for organisms. Fixed N can also be converted back to N2. Global cycling of N between inert and fixed forms has undergone drastic alterations in terms of form and flux over Earth history, with implications for the size and evolution of the biosphere and the biogeochemical cycling of carbon and trace metals. Natural processes of fixed nitrogen input (e.g. biological nitrogen fixation, lightning) and output (e.g. denitrification, anammox) have controlled the amount of nitrogen bioavailable for life until the recent Anthropocene. However, uncertainties remain on the contributions, controls, mechanisms, and evolution of nitrogen inputs and outputs, particularly during periods of environmental change. This session seeks to bring together researchers who employ a diverse array of cross-disciplinary tools including studies of the genes, proteins, metabolisms, isotopes, and models to address how nitrogen enters, is transformed, and exits the biosphere in modern and ancient systems over scales ranging from molecules to the globe. Specifically, we invite submissions related to the controls on nitrogen input and outputs across ecosystems; physiology and metabolism of diazotrophs, denitrifiers, and anammox bacteria; ancient global geochemical change based on protein/metabolism evolutionary history, mechanisms and applications of stable isotopes to track N inputs and outputs over Earth history, biochemistry of N cycling enzymes, as well as models of N availability informed by geochemistry and OMICS.

    Conveners:
    Xinning Zhang (Dept. of Geosciences, Princeton University)
    Betul Kacar (Dept. of Molecular and Cell Biology, Dept. of Astronomy, University of Arizona)
    Sebastian Kopf (Dept. of Geological Sciences, University of Colorado-Boulder)

    Website: https://agu.confex.com/agu/fm18/prelim.cgi/Session/52343

    Location: Washington DC, US