Over the last two decades, long-term ecological research in the United States has expanded to urban sites. Cities, despite the dominance of built structures, utilize unexpected amounts of human-generated nutrients. Additionally, cities can both intensify and weaken local impacts of processes such as climate. Challenges remain at these sites, as property-scale biogeochemical forcings from individuals and institutions must be accounted for throughout this research. Meeting the challenge is crucial as prediction of biogeochemical processes is fundamental to the development of sustainable strategies for managing human inputs to cities and surrounding areas.