Why Mapping Peatlands Matters for Water and the Climate

Peatlands—bogs, fens, and swampy wetlands built from centuries of slow-accumulating and decaying plant matter—are among the most quietly powerful ecosystems in the world. They filter and store water, support wildlife, buffer communities against floods and wildfires, and store vast amounts of carbon pollution. Yet despite these outsize benefits, peatlands remain poorly mapped and are often overlooked in conservation and land‑use planning.

The Pew Charitable Trusts’ Wetland Carbon Network recently brought together four experts—Meredith Cornett, peatland restoration program coordinator for the Minnesota Department of Natural Resources; Alex Moya, a Pew officer who advances state and federal natural climate solutions; Glen Delaney, director of partnerships for Earth Economics; and Dominic Uhelski, a wetland ecologist and postdoctoral scholar at Michigan Technological University—for a webinar highlighting new science and mapping tools that can help states better understand, value, protect, and restore peatlands.

These experts’ message was clear: Peatlands are not just climate assets; they are foundational natural infrastructure that improves community safety, water clarity, and ecological health.

Understanding the full value of peatlands

Delaney—whose organization specializes in quantifying the monetary value of ecosystem services, such as water filtration and wildfire risk reduction—opened the discussion by noting that these values rarely show up in traditional economic analyses. 

“Valuation is a tool to support peatland protection by articulating their benefits in a unit non‑ecologists can understand: the dollar,” he said.

He explained that, even though biophysical studies show that peatlands can store more carbon than other wetlands, they are rarely differentiated in valuation literature. He noted that peatlands also provide other niche ecological services, including disaster resilience; water regulation, such as supplying late‑season streamflow; and storage of mercury, a neurotoxin that can contaminate fish consumed by downstream communities.

And finally, he emphasized that when peatlands are drained or disturbed, their saturated soils dry out, making them far more vulnerable to deep‑burning fires that release carbon, mercury, and other pollutants.

Mapping peatlands is essential

Uhelski underscored that understanding peatlands begins with knowing where they are and what condition they’re in. “Mapping is important because peatlands are places,” he said. “Each distinct place has its own properties—its climate, land cover, and proximity to ditches or other land uses that might be causing impacts.”

Uhelski worked with the U.S. Forest Service to produce in 2025 the first map of peatland extent and condition in the contiguous U.S. and Hawaii, which revealed striking patterns. Many states, including Michigan, Minnesota, and Wisconsin, have substantial intact peatlands that deliver the benefits that Delaney detailed. Further, in these and other states, peatlands have been drained—primarily for agriculture, but also for road construction—which undermines and can even reverse the benefits, increasing flood and wildfire risk; releasing stored carbon, mercury, or other pollutants; and degrading water quality.

Mapping allows states to identify restoration opportunities, assess threats, and compare conservation and management approaches. It also helps land managers understand which peatlands are most important for water storage, which are most vulnerable to fire, and which could deliver the greatest ecological benefits if restored.

And, as Uhelski noted, mapping reveals opportunities for collaboration: “Minnesota, Wisconsin, and Michigan have similar peatland conditions, so there’s probably a lot of cross‑learning that could be done between those three states.”

Building a national picture

Moya described how Pew is partnering with the U.S. Forest Service, Michigan Tech Research Institute, and Germany’s Greifswald Mire Centre, an internationally recognized research, conservation, and policy institute, to build a refined U.S. peatland map that integrates data on land cover, hydrology, carbon stocks, emissions estimates, and biodiversity.

“The research teams are also currently in the process of better understanding where improved peatland data may have the greatest practical value,” Moya said.

The new map aims to identify peatland hot spots for conservation and restoration—places that offer the greatest potential for avoiding and reducing carbon pollution. This can help states incorporate peatlands into climate and hazard mitigation planning and conservation frameworks.

Putting peatland data into action

Minnesota contains nearly 7 million acres of peatlands—the largest concentration in the contiguous U.S.—but decades of drainage have degraded many of them. Cornett told webinar attendees that roughly 4,000 miles of drainage ditches intersect the state’s peatlands, drying soils that historically stored carbon and, in some cases, turning vital carbon sinks into significant sources of greenhouse gas emissions. This threat has made peatland restoration a priority in Minnesota's Climate Action Framework, the state’s blueprint for reducing carbon pollution and climate risk.

The state is demonstrating restoration techniques via projects, Cornett said. At one site, crews are using felled trees, brush bundles, and other natural materials to slow water flow, retain organic matter, and encourage peat-forming vegetation to regrow. At another area where natural materials are scarce, Excelsior bales—tightly packed bundles of shredded aspen wood fibers—can be placed in drainage ditches, where they act as natural plugs, slowing the movement of water, trapping organic matter, and helping to rewet dried peatlands.

“These pilot projects are really helping us learn and get our arms around this whole question of peatlands and how we can help them be the carbon sinks that they are meant to be,” Cornett said.

But successful restoration depends on more than science and engineering, she emphasized. Projects often require close coordination among state agencies, Tribal Nations, local governments, federal partners, drainage authorities, and private landowners. Minnesota officials are collaborating with the Red Lake Nation and supporting Tribal-led restoration priorities in partnership with the Minnesota Tribal Environmental Committee.

A conservation road map

The discussion made clear that peatlands are essential natural infrastructure that, though vulnerable to drainage and disturbance, offers some of the most powerful nature‑based solutions available to address climate challenges. Better valuation and mapping can help policymakers understand their full worth and prioritize investment of limited resources to best support conservation efforts. And greater coordination across agencies, Tribes, researchers, and landowners can bolster restoration and protection.

Peatlands are indispensable, and states now have a clearer path to put them on the map and keep them functioning for generations to come.

Jazmin Dagostino works on The Pew Charitable Trusts’ U.S. conservation project.