Sustainable river management requires strategically balancing the various, and often conflicting, demands placed on a river system. Human priorities must be met within a framework that also satisfies ecological needs. The challenge to provide for water supply demands while maintaining environmental flows is particularly striking in the water-limited Colorado River basin. The Colorado has historically been managed for complete reliability of water deliveries by taking advantage of the basin's large dams and extraordinary reservoir storage capacity. Within the past few decades, however, consumption has surpassed supply. This project will explore the dominant processes that shape the current condition of ecosystems along the large rivers of the Colorado River basin. Research results will help inform the management of ecologically sustainable water systems that integrate human and ecological needs. The project is supported under the NSF Science, Engineering and Education for Sustainability Fellows (SEES Fellows) program, with the goal of helping to enable discoveries needed to inform actions that lead to environmental, energy and societal sustainability while creating the necessary workforce to address these challenges. With SEES Fellows support, this project will enable a promising early career researcher to establish themselves in an independent research career related to sustainability.
This project develops, tests and applies a hydrologically driven model of riparian ecosystem dynamics for evaluation of ecosystem response to altered flow regimes. The dominant processes that shape the current condition of riparian ecosystems along the large rivers of the Colorado River basin will be captured in a modeling framework by building interrelated vegetation and geomorphic flow response curves. The interdisciplinary approach will push the one-way relationship characteristic of many vegetation response models towards a more realistic model of interactions and feedbacks between biotic and abiotic factors. Concepts and methods will be applied to two areas of the upper Colorado River basin that represent the variability in geomorphic organization, hydrologic alteration, sediment mass balance conditions, and management contexts that exist within the basin. The work takes advantage of the relatively well-established understanding of riparian ecology and geomorphology in these settings and proposes new field data collection and ecological, hydrologic, and hydraulic modeling. The project will 1) address both physical and ecological processes and their associated interactions, 2) integrate finer scale interactions that fundamentally shape ecosystems and the larger scales of river organization at which river managers work, 3) adopt the simple methodology of environmental gradients and non-taxonomic guilding of species based upon traits so that the approach may be generalized and applied over large spatial scales, and 4) provide a spatially-explicit identification of the trade-offs in riparian ecosystem condition for a given flow scenario. The SEES Fellow, Dr. Rebecca Manners, works with host mentor Dr. Andrew Wilcox at the University of Montana, and with partner mentor Dr. David Merritt at the USDA Forest Service National Stream and Aquatic Ecology Center in Fort Collins, Colorado. The project is co-funded by the EPSCoR program at NSF.
