Estimating the vulnerability of the property protection ecosystem service of tidal wetlands to climate change

Stressors such as climate change, pollution, and development affect ecosystem condition and consequently, they affect the goods and services that people use, appreciate, or enjoy that are produced by those ecosystems (i.e., ecosystem services, ES). Anticipating how ES are affected by stressors can allow stakeholders and managers to monitor key ecological attributes (KEAs) for changes of condition or to proactively protect or restore those features. We developed a conceptual framework and assessment methodology for identifying the KEAs necessary to produce ES, assessing the vulnerability of KEAs to stressors, and assessing which ecological processes can increase the resilience of KEAs to stressors. This method relies on mining existing information from peer-reviewed scientific articles. We demonstrate this method with a case study of the effects of storms and sea level rise (i.e., the stressors) on the property protection ES provided by tidal wetlands (i.e., the ecosystem). We identified 12 KEAs for the property protection ES, determined that KEA decline due to storms was most frequently associated with inundation (i.e., surge flooding), that decrease in wetland size/area was the most frequently reported impacted KEA primarily due to erosion, and that some KEAs (i.e., vegetation aboveground biomass and vegetation cover/density) can recover within 1 year of a storm, but others (i.e., wetland size/area and wetland platform elevation) can take more than 10 years to recover. A natural supply of sediment, accretion processes, plant growth and reproduction, and upland space for marsh migration were most frequently cited as processes that increase the resilience of KEAs. Our results also identify priority end points for condition-assessment monitoring and needs for research to fill critical knowledge gaps. The framework and assessment methodology are applicable to any ecosystem type, ES, and type of stressor, limited by the availability of published scientific information.

Impact/Purpose

An EPA-ORD team has developed and demonstrated a general assessment methodology to characterize how major stressors, such as climate change or pollution, can affect the production of valued ecosystem services (ES), and how to identify opportunities to improve the resilience of those ES. Ecosystem services are the natural features or processes that people use, enjoy, or appreciate and thereby improve human well-being (e.g., health, economy, fulfillment). The new assessment methodology relies on mining existing information from scientific studies, including journal articles and government agency reports. The team used the method to investigate the vulnerability and resilience of the property protection ES provided by tidal marshes. In short, friction produced by marsh vegetation slows flooding by storm surge and dampens waves, thus providing some protection to upland property or structures. Several key ecological attributes (KEAs) of marshes contribute to producing that ES, including vegetation density, height, and stiffness, wetland area, and the elevation of the wetland platform. The team found that several KEAs are vulnerable to storm impacts and sea level rise (SLR), but that other ecological processes can increase the resilience of the KEAs to storms and SLR (such as sediment supply and accretion, plant growth and reproduction, and upland areas where marshes can migrate into). The team demonstrates how these results can be used within existing coastal planning efforts, such as EPA’s Climate Ready Estuaries program. The results also identify priority end points for condition-assessment monitoring and needs for research to fill critical knowledge gaps. This general assessment methodology is applicable to any ecosystem type, ES, and type of stressor, limited by the availability of published scientific information.

Citation

Folger, C., T. DeWitt, A. Borde, J. Wilson, AND R. Graham. Estimating the vulnerability of the property protection ecosystem service of tidal wetlands to climate change. Restore America's Estuaries (RAE) Summit, New Orleans, LA, December 05 - 08, 2022.