PeatRestore: National Mapping, Condition Analysis, and Restoration Decision Support Tools for Peatlands, One of the Largest Vulnerable Carbon Pools on the Planet and a Source of Mercury

Peatlands (forested and unforested bogs and fens) are sensitive to management activities that can disrupt hydrology, affecting ecosystem integrity, erosion, water quality, and other ecosystem services. Peatland drainage and conversion to other uses such as forestry and agriculture can lead to the release of carbon dioxide to the atmosphere, which can have dire consequences for the global carbon cycle.

Peatlands are especially sensitive ecosystems that have relevance to climate because of their high carbon storage per unit area. While peatlands only cover approximately 3 percent of the earth’s land surface, they store upwards of 30 percent of global soil carbon. Both protecting and restoring peatlands have been identified as two of the most impactful Natural Climate Solutions (NCS) globally and peatland restoration is one of the NCS identified as critical in the U.S. for reaching Paris Accord targets.

Peatlands are also known sources of both elemental and methyl mercury from current and previous industrial atmospheric deposition. Under the right conditions, such as where there is low oxygen, and ample sulfate and carbon, such as in peatlands, elemental mercury can be biologically transformed to the bioaccumulative form methyl mercury. The methyl mercury is transported downstream to fisheries leading to fish consumption advisories, but there is little known about how ditched peatlands change downstream transport of mercury, and even less is known on the effect of peatland hydrologic restoration on mercury cycling. Although little is known, drainage is hypothesized to release mercury from peat, which affects stream water quality, leading to mercury bioaccumulation in fish and mercury toxicity in humans and fish-consuming wildlife.

Objectives

This project will accelerate and assess peatland restoration by focusing on four primary objectives:

1. A National Peatland Condition Map. This project will produce a national peatland condition map and analysis, and map-based decision support tool for prioritizing peatland restoration activities based on impact on greenhouse gases and stream water mercury export, ownership, feasibility, cost, and other factors. 
2. Decision Support and Training. The project will result in development of a peatland restoration decision support tool, region-specific peatland restoration guides, and restoration trainings in different footprints, including tribal, federal, state and private ownerships.
3. A Restoration Impact Assessment. In large areas of Minnesota, peatlands have been dissected by an extensive system of ditches. These landscapes are complex areas of state, Tribal, federal, and private lands requiring co-management of resources. This project will expand existing restoration monitoring efforts across Minnesota, with analysis of restoration impact on stream water mercury, peatland ecosystem production, and greenhouse gas emissions.
4. First Ever Peatland Maps on National Forest System Lands. To fill gaps in the national peatland map and condition assessment, for areas not covered by the Soil Survey Geographic Database (SSURGO) in the West, this project will develop high accuracy maps of peatlands and other wetlands and their condition (drainage, roads, mining impacts) on selected National Forest and adjacent federal lands using remote sensing, ground truthing, and random forest modeling.  

Expected Results

Outputs

• Interactive national peatland condition map covering public and private lands in the contiguous United States (CONUS).
• Remote-sensing and ground-truth based peatland distribution and condition maps on five Western and one Eastern peat-rich National Forests.
• Spatially explicit peatland restoration decision support tool deployed, and peatland restoration guides and regional trainings deployed for different regions (southern, northern, western).
• Greenhouse gas (GHG) emissions and stream water mercury impact assessment for restored peatlands to determine net benefits of restoration.

Expected Outcomes

• Improved manager ability to identify, prioritize restoration of, and effectively restore peatlands.
• Higher net ecosystem production and resultant increased carbon storage on peatlands.
• Reduced mercury in streams leaving peatlands.
• Improving Watershed Condition Classes.

Metrics of Success

• Adoption of tools for restoration planning across public, private, and tribal lands.
• Number of managers trained in restoration practices.
• Higher net ecosystem production and lowered measured CO₂ emissions and mercury export in restored peatlands.
• Increased number of projects and area per year undergoing peatland restoration.

Geographies and High-Risk Landscapes to Be Addressed

National