Wetland accretion and vegetation growth model integration and application to coastal wetland management | W81EWF 20 SOI 0032

Frequently Asked Questions (FAQs)

What is this grant opportunity about?

This opportunity from the U.S. Army Corps of Engineers (USACE), Department of Defense, supports work to improve long-term planning and management of coastal wetlands by building better predictive modeling tools. The aim is to reduce uncertainty about whether wetlands will remain functional over typical USACE project timeframes (about 50 years), especially as conditions change due to sea level rise, storms, sediment supply shifts, and restoration actions.

Why are coastal wetlands important in this program?

Coastal wetlands provide multiple ecosystem and community benefits, including wildlife habitat, carbon storage, shoreline erosion control, and economic benefits linked to recreation and tourism. They are also increasingly used in flood risk management because wetlands can reduce wave energy and storm surge impacts.

What problem is USACE trying to solve?

The central problem is uncertainty about wetland sustainability over long project life cycles. Wetland performance depends heavily on elevation (relative to sea level) and vegetation type/density. These drivers can change over time, altering how well wetlands attenuate waves and surge and how they deliver other services such as habitat and carbon sequestration.

What does "wetland sustainability" mean in the context of this grant?

In this context, sustainability refers to whether wetlands can maintain key physical and ecological characteristics over time, particularly elevation and vegetation structure, without losing function. It also includes whether periodic interventions (maintenance or restoration actions) may be needed to keep wetlands functional.

What types of future conditions should the model be able to evaluate?

The modeling capability is expected to forecast wetland elevation and vegetation responses under different future conditions, including sea level rise trajectories, storm disturbance, restoration actions, and other changing environmental drivers.

What is the anticipated technical approach?

The anticipated work is to integrate (couple) wetland accretion dynamics with an existing USACE process-based vegetation growth model that is being adapted for coastal wetlands. The intent is a coupled system that represents feedbacks between vegetation and elevation, rather than running separate models in parallel.

What are "accretion dynamics" as described in the announcement?

Accretion dynamics are the processes that build or reduce wetland elevation over time. The announcement references mineral sediment deposition, organic matter accumulation from plant production, compaction, erosion, and subsidence as key examples.

Why does the opportunity emphasize coupling vegetation and elevation processes?

In real wetlands, vegetation can influence sediment trapping and organic accumulation, which affect elevation. At the same time, elevation and flooding frequency influence plant growth, stress, and species composition. The grant is focused on representing these two-way interactions so managers can explore how wetlands evolve and what actions might be needed to maintain performance.

What are the key objectives of the work?

The announcement outlines these objectives: (1) identify which processes from existing accretion models are essential and determine technical requirements for coupling, including decisions about spatial scale and coupling time steps; (2) fully integrate accretion and vegetation models for at least one focal species as a working prototype; (3) expand the model to include interspecies dynamics and competition, including invasive species colonization and management actions; and (4) produce case studies and practical application examples, emphasizing sites in the southeastern United States.

What decisions about scale and time step are explicitly mentioned?

The opportunity calls for decisions on spatial scale (for example, plot scale versus marsh platform scale) and on coupling time steps (how often models exchange information, such as daily, monthly, or annually).

Is the goal to create a decision-support tool or a purely academic model?

Based on the announcement, the goal is an applied, decision-support oriented modeling capability that helps USACE and partners plan, evaluate, and maintain wetland-based coastal risk reduction and restoration projects under long-term environmental change.

Does the work require a prototype?

Yes. The objectives include full integration of the accretion and vegetation models for at least one focal species, producing a working prototype that demonstrates the coupled framework.

Does the model need to address multiple plant species?

Yes. After the initial prototype for at least one focal species, the work is expected to expand to include interspecies dynamics and competition.

How are invasive species addressed in the expected work?

The objectives explicitly include accounting for invasive species colonization and management actions and how these factors can alter vegetation outcomes and accretion processes.

Are case studies required?

Yes. The effort must produce case studies and practical application examples showing how the integrated model can be used in a project life cycle context.

Is there a geographic emphasis for the case studies?

Yes. The announcement emphasizes sites in the southeastern United States due to the prominence of coastal wetland management needs and storm risk concerns in that region.

How does this relate to coastal storm risk management projects?

The opportunity is framed around the increasing use of wetlands as components within coastal storm risk management systems. Because wetlands can reduce wave energy and storm surge impacts, USACE is seeking tools to predict whether wetlands will maintain elevation and vegetation structure over time to support risk reduction performance.

How does navigation dredging relate to this opportunity?

The announcement notes that wetland restoration is increasingly paired with navigation dredging, for example by placing dredged sediment to rebuild marshes. This creates a need for better predictive tools to anticipate how such actions influence long-term elevation and vegetation outcomes.

What is the anticipated project timeline context the model should support?

The model is intended to address wetland sustainability over a typical USACE project life cycle of about 50 years, supporting long-term expectations and maintenance planning.

What type of award instrument is this?

This opportunity is described as a discretionary cooperative agreement, which means substantial involvement by the government partner is expected during the project.

What is the Funding Opportunity Number and CFDA listing?

The Funding Opportunity Number is W81EWF 20 SOI 0032 and the CFDA number listed is 12.630.

When was the opportunity posted and what was the original closing date?

It was posted on June 4, 2020, with an original closing date of July 31, 2020.

How much funding is available?

The funding ceiling listed in the announcement is $15,000.

How many awards does the agency expect to make?

The announcement indicates the agency expected to make a single award.

Who is eligible to apply?

Eligible applicants are described broadly as "Others," with additional eligibility details referenced in the full announcement.

What kind of outputs is USACE likely looking for based on the description?

Based on the stated objectives, expected outputs include a coupled accretion-vegetation modeling capability, a working prototype for at least one focal species, an expanded version that handles interspecies competition (including invasive species and management actions), and case studies demonstrating practical application across a project life cycle, especially in the southeastern United States.

What wetland characteristics are most central to the modeling goal?

The announcement highlights two linked characteristics as central: elevation (bathymetry/topography relative to sea level) and vegetation type and density, because these largely determine wave and surge attenuation and influence other services such as habitat quality and carbon sequestration.

What environmental drivers are mentioned as affecting wetland performance?

The announcement mentions sea level rise, storm events, changes in sediment supply, and restoration actions as drivers that can shift elevation and plant communities and either strengthen or degrade wetland function.

What makes this modeling effort different from simply combining two existing models?

The announcement states the intent is not just to run two models side by side, but to couple them so that feedbacks between plants and elevation are represented, reflecting two-way interactions observed in real wetlands.