Integration of Human Choice into Models of Biogeochemical Cycling in Urban Ecosystems

Despite the growing importance of cities as biogeochemical hotspots, little is known about factors influencing elemental fluxes through individual households, even though the aggregate consumption by households likely has a substantial effect on fluxes of major elements like carbon (C), nitrogen (N), and phosphorus (P) that have implications for local, regional and global pollution. The overall goal of this interdisciplinary research project is to couple human behavior with flows of macroelements (C, N, and P) through households. The investigators will quantify total fluxes of C, N, and P through households in the Twin Cities of Minneapolis-St. Paul, Minnesota, and they will look to expand basic understanding of the factors that influence household choices regarding consumption and macroelement fluxes through households. The investigators hypothesize that element fluxes are highly variable and skewed, with relatively few households contributing disproportionately to overall fluxes. Another hypothesis to be tested posits that the magnitude of elemental fluxes through households can be predicted from knowledge of daily consumption choices along with long-term choices regarding household infrastructure, such as house size and lawn area. To test these hypotheses, 400 owner-occupied, single unit households in Ramsey County will be randomly selected to cover a range of household characteristics. These households will be studied using an intensive mail survey, a landscape inventory, and homeowner energy bills. Data will be entered into a previously developed Household Flux Calculator (HFC) model to generate fluxes of C, N, and P. Survey data will additionally be used to link element fluxes with factors related to human choices like attitudes, norms, perceived control, and demographic factors. This project is expected to integrate human choice and biophysical characteristics into a model of household biogeochemistry using a transdisciplinary approach that integrates biophysical and social research approaches. The project will provide research opportunities for post-docs, graduate students, and undergraduate students. By incorporating the HFC directly into classroom education, it will allow students to explore hypotheses regarding impacts of consumption. In addition, project outcomes will be used to help develop a new paradigm for pollution control, one based on source reduction and information feedback loops to guide adaptive management. This project is supported by an award resulting from the NSF competition focusing on the Dynamics of Coupled Natural and Human Systems.