'Systems Modeling to Improve the Hydro-Ecological Performance of Diked Wetlands'
Omar Alminagorta (email@example.com), Utah State University; David Rosenberg (firstname.lastname@example.org), Utah State University; Karin Kettenring (email@example.com), Ecology Center and the Department of Watershed Sciences, Utah State University
We developed a systems model to recommend water allocations and invasive plant management to improve hydro-ecological performance of diked wetlands. Model recommendations are subject to constraints like water availability, spatial connectivity of wetland units, hydraulic infrastructure capacities, vegetation growth and responses to management, plus financial and time resources available to manage invasive vegetation and water. We developed a hydro-ecological performance metric which we call the weighted usable area for wetlands that represent the available surface area that provides suitable hydrological and ecological conditions for priority bird species. The metric combines habitat suitability indices, water depth, vegetation cover, weights by priority species and the wetted surface. We applied the model at the Bear River Migratory Bird Refuge, which is the largest wetland complex on the Great Salt Lake, Utah. Stakeholders participated by helping to identify the problem through interpreting results. We ran the model for a base case representing hydrologic conditions in 2008 and seven scenarios that independently consider changes in water availability, financial budget, vegetation responses, and gate operation. We compared model-recommended management actions to past management activities and found that more dynamically managing water levels can increase by almost two-fold wetland hydro-ecological performance. Model results also show that wetland performance is more sensitive to changes in vegetation response, gate operation, and water availability than to changes in the financial budget. This participatory modeling effort demonstrates a framework to develop and apply hydro-ecological performance metrics for wetlands and embed those metrics in models that recommend management to improve wetland performance.