Potential for Additional Carbon Sequestration through Regeneration of Nonstocked Forest Land in the United States

An analysis of 2014 forest inventory data for the contiguous United States shows nearly 8 million ha of forestland that are currently defined as nonstocked after recent natural and human disturbances. It is estimated that forest regeneration on these lands could result in an additional terrestrial sequestration of 48.9 million metric tons of CO₂ equivalent (CO₂e) annually. Analysis across a range of seven site productivity classes indicates that approximately 58% of the total area is productive timberland, defined as capable of producing merchantable volume of ≥1.4 m³/ha/year. It is estimated that regeneration of just the productive timberland portion of the total could produce an additional 44.4 million metric tons of CO₂e annually in carbon sequestration. On National Forest System lands, more than 50% of the total potential carbon sequestration benefit from regenerating nonstocked lands could be achieved by reforesting just the top 30% of these lands in the moderate-to-high site productivity classes. On private lands, more than 70% of the total potential carbon benefit can be achieved by regenerating the most productive 30%.

Management and Policy Implications As the nation's largest carbon sink, forests will play an essential role in achieving national policy goals for net reductions in CO₂, and regeneration of currently nonstocked forestland is a key component in this strategy. Timely forest regeneration after both past and future timber harvest or natural disturbance is key to sustaining an array of goods and services from forest ecosystems, including but not limited to carbon. This has been recognized in federal policy through numerous financial incentive programs and tax policies to support reforestation on private lands and mechanisms such as the Knutson-Vandenberg Act and the Reforestation Trust Fund to support reforestation on public lands. Regenerating the most productive 30% (by site productivity class) could achieve 70% of the total potential carbon benefit on private lands and 50% of that on National Forests. Detailed analysis of the type of reforestation investments needed and a reevaluation of existing policies promoting forest regeneration on public and private lands are needed to direct reforestation assistance to the most productive opportunities and to provide forest managers with the resources and tools necessary to make sound public investments in the future of the nation's forests and environment.

forest regeneration, reforestation, forest carbon, climate change mitigation, climate policy