Suisun Landscapes

As the largest brackish marsh on the West Coast, Suisun Marsh is a unique transitional landscape between the Bay and the Delta portions of the Estuary. The Marsh has long been managed for recreational hunting and native biodiversity, yet it is threatened by an uncertain future under climate change. Sea level rise and increasing salinity pose significant threats to the current structure and uses of the Marsh. Likely impacts include conversion of wetlands to open water, changes in species composition, increased flood risk, and drainage challenges in managed wetlands. A functioning marsh that supports fish, waterfowl, recreation, and other functions of interest into the future will need effective adaptation planning and coordination among landowners, resource managers, tribes, and other stakeholders. 

The Suisun Landscapes project will facilitate and support these efforts by expanding the currently available tools for adaptation planning in Suisun to include spatially explicit representations of the historical function and condition of the marsh, priority features and functions for human use, and measurement of change over time. The tools and spatial analyses produced during the Suisun Landscapes project will support the work of the Suisun Marsh Plan AMAT and others, enhancing capacity to estimate and track effects of projects in Suisun on Delta Plan Performance Measures.

Our quantitative and spatial approach for the Suisun Landscapes project has previously been successful in supporting large-scale planning in the Delta through detailed investigations into the Delta’s historical ecology, historical land use change, and landscape potential for future restoration, as well as the Landscape Scenario Planning Tool (LSPT). The LSPT analysis extent was expanded to include Suisun Marsh in 2022. However, the existing and planned analyses and metrics (such as crop revenues and potential carbon offsets value) reflect Delta priorities, which may differ from priorities for Suisun Marsh. For example, there is less crop cultivation in Suisun and waterfowl habitat for recreational hunting is of greater importance. Therefore it is necessary to involve the local community throughout this project to identify priorities for Suisun and provide guidance during development of the datasets, reports, and tools. A greater focus on community interests will enhance the capacity of the LSPT and Delta-Suisun planning and management as a whole to evaluate potential trade-offs and synergies between social, economic, and ecological benefits. The inclusion of these perspectives while the tools are being developed will increase representation and equity in future planning work, addressing the potential for a conservation bias that neglects the needs of local interests.

The objectives of the Suisun Landscapes project are to: 

• Facilitate landscape planning with the best available science so that the future Suisun Marsh is more resilient and reflects community priorities regarding desired ecosystem functions and services (potentially including support for endangered fish, waterfowl habitat and recreation). 
• Generate a spatially explicit and quantitative understanding of Suisun’s historical ecology (through maps, metrics, etc.), using in-depth analysis of primary sources. 
• Understand community priorities for Suisun Marsh and foster dialogue and buy-in through the process of co-developing planning resources to include current uses of the landscape and perceived future challenges.
• Evaluate how the ability of the Suisun landscape to support desired ecosystem functions and services has changed over time, and lay the foundation of knowledge to evaluate opportunities to restore lost function. 
• Support landscape planning and design in Suisun by developing spatially explicit scenario analysis tools (LSPT analyses) that draw from information on historical ecology, community priorities, and past landscape changes, and account for climate change effects (potentially including sea level rise, salinity changes, temperature increase). 
• Make information on Suisun historical ecology, environmental history, landscape change, and community priorities accessible to a broad scientific and stakeholder community.

Photo credit: California Department of Fish and Wildlife via Flickr (CC BY 2.0)