Riparian corridors in arid regions are the narrow ribbons of trees along streams that shelter some of the most important biodiversity in the landscape. The combination of climate change, human withdrawals of water, and land use decisions threaten stream flow and shallow groundwater that is crucial to the maintenance of riparian corridors. Linked biophysical and societal stresses can push riparian systems across critical thresholds, tipping points beyond which restoration to earlier conditions is unlikely. This can cause loss of broader social-ecological resilience; that is, the capacity of systems to retain essential functions, including provision of water and other ecosystem services. This project will improve understanding of how changes in social and natural processes affect the resilience of riparian systems and, by extension, the ecosystem services these systems provide. Research will focus on two adjacent river systems: the Upper San Pedro River, flowing northward from Sonora, Mexico into Arizona in the United States, and the Upper Sonora River, flowing south within Sonora. An agent-based model will be created to translate interactions among environmental conditions, societal rules, and human practices into likely changes to the riparian corridors under study. This project will answer critical questions about coupled human and ecological processes in riparian systems; responses of riparian systems to stresses; and how crossing thresholds can be assessed.
This research will develop new techniques for modeling social-ecological interactions in riparian corridors that will have direct application in the management of stream ecosystems. The project will provide opportunities for stakeholders at all levels, from officials managing natural resources, to individuals visiting riparian corridors, to use science-based tools for informed decision-making. This work engages stakeholders across national boundaries in participatory science and management of ecosystem services. This project will also contribute to education at K-12 grade levels and provide research training for undergraduate and graduate students.