By Dorothy Hastings

Tree tubes
Tree tubes are used to grow trees on marginal agricultural land, a soil carbon enhancement strategy. Credit: Eric Sprague.

WHEN STANDING in a beautiful forest, it can be easy to forget you are standing in the largest carbon storage unit in the U.S., and that the soil beneath your feet is responsible for most of it. Protecting our forests means protecting our soil, and American Forests, The Northern Institute of Applied Climate Science (NIACS), the University of Michigan and State of Maryland are partnering on a project that will protect and enhance soil carbon storage and sequestration in forests across North America.

The project focuses on forest restoration as a means to hold more carbon, identification of the best forest management practices for soil carbon, and building an understanding of the contribution each managed forest makes to climate change mitigation.

“When you think about conservation at large, virtually any issue is too large for a single organization,” says Chris Swanston, director of NIACS. “American Forests has a core mission around forest restoration and supporting working forests, and NIACS has a core mission around helping land managers pursue climate-informed forest stewardship.”

The project is partly funded by the Sustainable Forestry Initiative (SFI), which has the largest forest-managed footprint of any forest management standard world-wide.

“It’s our belief that managed forests have an important role to play in ensuring that as much carbon is captured from the atmosphere as possible in an effort to combat greenhouse gases,” says Paul Trianosky, chief conservation officer at SFI. “With that in mind, the work of American Forests is going to be really important to help us identify what practices help promote those out-comes that we care about.”

Seventy-five percent of carbon in forests is stored in the soil, and the carbon sequestration process that occurs in forests is fundamental to greenhouse gas mitigation. Therefore, ensuring that forest management practices prioritize protecting and increasing soil carbon is imperative in climate change adaptation. Yet, past climate mitigation efforts and incentives have generally focused on impacting limbs, tree trunks and other components of aboveground live biomass. This lack of attention to soils has been generally due to limited data on forest soil carbon and lack of clarity regarding what actions landowners can take to positively or negatively impact this carbon pool.

American Forests is working with partners to synthesize national and regional datasets to broadly assess the differential impact of forest practices. Work to date by NIACS and others shows that practices like tree planting can build soil carbon stocks, while thinning and prescribed burns can help avoid future carbon losses. These larger datasets will then be combined with local data to develop forest soil carbon practices for specific forest types and geographies in Maryland and surrounding states. The approach will result in detailed tools and guidance that will be accessible and usable by SFI, as well as landowners, land managers and policymakers to meet forest health and climate goals.

“Soil carbon sequestration is a hard thing to foster,” says Swanston. “I hope that we can continue to learn how to do that in a way that helps store carbon for long periods of time in soils which have very strong feedback into supporting healthy forests.”

American Forests has already begun working with the Maryland Department of Natural Resources Forest Service to gather data on forest management practices that benefit soil carbon storage in the state, and to determine how these practices can be applied to different forest types across North America.

Prioritizing soil carbon not only protects against climate change, it benefits biodiversity, water quality, species conservation and other ecosystem services that contribute to forest health and maintenance.

American Forests and NIACS

Dorothy Hastings was an American Forests summer editorial intern and is a senior at American University studying journalism with a minor in American studies.