There is a pressing need to identify which elements of the coupled natural-human system are most sensitive to changes in land use and climate in the sense that they are likely to respond strongly to changes in these factors. Means of identifying such ?hot spots? of sensitivity to change would allow us to target remediation and other management measures where they will do the most good. This project will test and explore the ecologic and management implications of a novel hypothesis termed human-amplified natural change (HANC), which states that the areas of the landscape that are most susceptible to human, climatic, and other external changes are those undergoing the highest natural rates of change.
The research team will develop a theoretical framework for vulnerability assessment and will test the HANC hypothesis through intensive study of the Minnesota River Basin (MRB), a 44,000 km2 agriculturally-dominated watershed in the upper Midwest. The MRB encompasses an extremely broad spectrum of natural and human-induced rates of change and sensitivity to land-use practices. Of particular interest is the complex nonlinear coupling between land use and river network processes, which has already resulted in severely impaired waters for sediment and nutrients. What will be the future condition of the waters and ecosystem services in the MRB under changing human actions and climatic conditions? Of the many potential land and water management options, which are most likely to produce a sustainable, resilient, and thriving coupled economic-environmental system? To answer such questions, this study seeks to:
(1) determine the extent to which current high rates of sediment production are concentrated in areas that were undergoing high rates of natural change before the external changes were imposed; (2) study how thresholds and localized features in the system amplify and accelerate change and how such nonlinear effects can be parameterized in an integrated predictive modeling framework; (3) investigate the extent to which the human-amplified natural changes (HANC) in the geomorphic system contribute to observed ecological changes in the MRB; and (4) develop means to include HANC-based reasoning in decision analysis frameworks, including a suite of methods to identify sensitive regions, along with spatially targeted monitoring activities.
Broader Impacts: Strong relationships previously developed with State regulatory agencies will ensure that the results from this project directly influence future land and water policy and management decisions. The research team will disseminate new knowledge directly to the public in close collaboration with State agencies via stakeholder meetings, widely attended regional meetings and informational reports. Further, they will develop a HANC-based analytical toolbox for evaluating areas prone to rapid change in the landscape, beginning with Midwestern agricultural landscapes. New knowledge generated from this work will be used to inform Science Museum exhibits related to the Anthropocene, develop innovative K-12 curricula in environmental science and engineering, and disseminate NSF?s Earth Science and Climate Literacy Principles via teacher training. The project supports three early-career PIs and training of graduate, undergraduate, and ?synthesis-postdoctoral? students in an interdisciplinary environment, co-advised by scientists in hydrology, geomorphology, ecology, biology, engineering, and economics.
