Denitrification serves as an important pathway for fixed nitrogen loss, producing inert dinitrogen when complete but the potent greenhouse gas nitrous oxide when incomplete. Comparative genomics and physiology have allowed our understanding of how denitrifiers denitrify to come along in leaps and bounds, but has also opened a number of questions regarding why denitrification is such a diverse and branching process. The objective of this work is to determine how environmental factors drive denitrification and its competing pathways. In this next stage of the project, I will also initiate some trait-based modeling.