Research Themes

Coastal Wetlands Restoration: Climate Action, Societal, and Ecosystem Conservation Benefits

Wetlands are valuable ecosystems that provide numerous benefits to humans, such as wave mitigation, habitat for important species, and carbon sequestration. However, many of these services have been lost or degraded due to human activities. Wetland restoration has the potential to revive these lost services, but it's a complex process that requires both natural and social considerations.

Our proposal aims to provide restoration guidelines that maximize societal benefits, with a focus on carbon sequestration, while ensuring the sustainability and biodiversity of wetland systems. To achieve this goal, our research is divided into four themes:

Carbon Dynamics

We will delineate the natural processes that control carbon dynamics in wetlands

Ecosystem Services

We will quantify the various ecosystem services provided by coastal wetlands and assess the carbon economics related to restoration.

Policy & Governance

We will examine the governance and environmental justice considerations associated with restoration projects.

Climate Modeling

We will construct process-based ecosystem and climate models for coastal wetlands and project how climate changes and sea-level rise impact carbon dynamics.

One of our fields sites in the Yampah Marsh in Elkhorn Slough.

Carbon Dynamics in Coastal Wetlands

Wetlands encompass a diverse range of aquatic ecosystems such as marshes, swamps, and bogs. These ecosystems possess an outsized proportion of the Earth's total soil carbon, holding 20-30% of the estimated 1,500 Pg of soil carbon, despite occupying only 5-8% of its land surface. This is because wetland soils are typically rich in organic carbon (>20%). However, as part of the carbon decomposition process, wetlands also emit greenhouse gases. The net carbon burial rates in wetlands are highly variable and are dependent on a wide range of factors such as elevation, vegetation, inundation, and salinity. Thus, comprehending the hydro-biogeochemical processes that govern these net carbon burial rates is essential for formulating effective wetland restoration and management guidelines that optimize carbon sequestration, and thus, facilitate the inclusion of coastal wetland restoration and conservation as a viable nature-based decarbonization strategy.
     To capture the vast array of coastal wetland conditions in California our field work focuses on estimating the processes controlling carbon dynamics and greenhouse gas emissions in representative wetlands in the San Joaquin Delta, South San Francisco Bay, and Elkhorn Slough. More resources including background information about the topic in general and our wetland sites can be found here.   

Elkhorn Slough: Photo by Don DeBold

Ecosystem Services of Coastal Wetlands

Nature-based solutions for climate mitigation, such as restoring wetlands, also provide additional benefits such as habitat for endangered species or climate adaptation benefits such as flood control. These benefits need to be modeled in conjunction with C sequestration benefits to determine the extent of complementary benefits versus trade-offs, and how a regional system of nature-based solutions can provide the highest level of joint benefits. Yet, linking the economic value of distinct ecosystem services to restoration decisions is still a significant challenge. The economic value of C storage and other wetland ecosystem services should be included in decisions on wetland restoration to support the mainstreaming of nature-based solutions into broader adaptation efforts.

Sacramento City Hall

Policy and Governance to Support Coastal Wetland Restoration

Implementing nature-based decarbonization solutions at the local level requires overcoming multi-scale governance challenges and regional cooperation. These challenges include developing local and regional plans, securing funding, and permitting, leveraging science and political leadership, and fostering community engagement. Overcoming these challenges requires coordinated action by local, regional, state, and national government agencies and/or jurisdictions, focused on co-producing and maintaining nature-based infrastructure that complements built infrastructure, enhances environmental equity and social justice, and provides incentives and resources for long-term resource stewardship. We need a wetland restoration policy and governance framework that considers multiple benefits and aims to enhance social-ecological resilience and incorporate environmental justice.

Coastal Wetlands Management and Climate Change Impacts on Decarbonization Efficiency

Wetlands are important carbon sinks to combat climate change and contribute to California's goals of meeting legislated targets under AB 32. However, human decisions on wetland restoration practices and climate change will affect their carbon sequestration potential and related ecosystem services. Therefore, incorporating wetland carbon dynamics, restoration options, and climate trends in ecosystem models can improve projections of wetland carbon benefits and optimize their use in decarbonization plans and policies.

Computer Cluster