Susan A. Masino, the Vernon Roosa Professor of Applied Science at Trinity College and currently a Charles Bullard Fellow at Harvard Forest, has co-authored a paper that singles out “proforestation” – growing existing natural forests – as key to addressing the accelerating global crises in climate and biodiversity. In many areas, proforestation is a more rapid, powerful, and practical option for sequestering carbon than afforestation (planting trees) or reforestation (replacing logged forests), according to the paper.

Susan A. Masino, the Vernon Roosa Professor of Applied Science at Trinity College
Susan A. Masino, Vernon Roosa Professor of Applied Science at Trinity College

The report, titled “Intact Forests in the United States: Proforestation Mitigates Climate Change and Serves the Greatest Good,” was published in the international journal Frontiers in Forests and Global Change as part of a special research issue on “Intact Forests.” It was co-authored by Masino, William R. Moomaw, climate scientist and Emeritus professor at The Fletcher School and co-director of the Global Development and Environment Institute at Tufts University, and senior ecologist Edward K. Faison of Highstead Foundation, an affiliate of Harvard Forest.

Increased carbon sequestration by forests is required to increase negative emissions and stabilize CO2 levels – an urgent goal to protect biodiversity and avert catastrophic tipping points, according to the paper. Global restoration of trees has been recently identified as the most powerful tool available to reduce emissions, the authors said, and protecting forests is also the most effective means for protecting the greatest land-based biodiversity.

Masino noted that forests also support public health – especially brain health – and that they are a rich source of new medicines. “Public land must be dedicated to the public good,” Masino said. “Aside from the climate crisis, as we become more urbanized, natural forests will become even more valuable for respite, recreation, science, and many physiological benefits. We need to immediately reassess policies and leverage interdisciplinary science without any conflicts of interest.”

The Intergovernmental Panel on Climate Change (IPCC) special report released on August 8, 2019, focused on preventing deforestation and afforestation but did not specify proforestation as a critical strategy. Moomaw, lead author on multiple previous IPCC reports, noted that growing existing forests has been overlooked and underutilized, particularly in the United States. “Based on emerging science, it is time to focus squarely on maximizing the potential of the forests we already have,” Moomaw said. “No other strategy is as effective immediately and in the coming decades when we need it most. Forests can mitigate the climate crisis significantly and protect many species from extinction if we allow them to function as they have been doing for millions of years.” Moomaw founded and directed the Center for International Environment and Resource Policy at The Fletcher School at Tufts University and is also the board chair of the Woods Hole Research Center and the North American board of the Climate Group.

In the report, New England is showcased as a forested region with significant potential for proforestation, with carbon-dense temperate forests with sequestration rates that can accelerate for many decades. Only about 2 percent of New England overall is protected legally as a nature preserve, i.e. similar to a National Park, a wilderness area, or the constitutional “Forever Wild” clause protecting the Adirondacks. The majority of heavily populated Southern New England (Connecticut, Massachusetts, and Rhode Island) is forested but only about 1 percent of the land base is protected. Regional groups working to increase this percentage include the Northeast Wilderness Trust and the Wildlands and Woodlands initiative.

A current bill in the Massachusetts legislature, House Bill 897 – “An Act for Forest Protection” – would update outdated laws and make Massachusetts a national leader prioritizing proforestation on public land. More than 70 percent of Massachusetts forestland is owned privately, and H. 897 would designate state-owned natural land as “reserves” or “parks” – no longer managed for commercial timber, with all current uses grandfathered in and interventions allowed as needed. These public lands add up to about 13 percent of the state, and similar to the documented local and regional benefits of National Parks, H. 897 is expected to increase tourism and recreation and provide a variety of economic opportunities – including new forestry jobs in monitoring and natural stewardship.

Faison emphasized important structural and habitat features that develop in forests over time. Faison noted that in addition to storing higher amounts of carbon, natural “wildland” forests tend to have more complex structures – i.e., greater numbers of dead standing trees, large pieces of downed wood, large living trees and greater tree species richness than managed forests – all of which can increase the diversity and abundance of many types of organisms. Over time, Faison noted, “older, unmanaged stands naturally develop large openings from storms, insect outbreaks, and the natural decline of large trees, providing additional habitat for a range of species that utilize forests openings and wooded areas with reduced tree cover.” The report cited numerous studies finding that natural “unmanaged” forests in the United States have higher carbon storage and sequestration, fewer invasives, lower burn intensity, and a greater diversity of many types of organisms.

The authors emphasized that when considering carbon, it’s not just about the trees. “A lot more carbon than we thought is stored in and continues to accumulate in soil and wetlands; storing it takes a long time, but disturbing it releases it immediately. Intact forests and wetlands are also our best protection from flooding – a problem that is only going to get much worse in our changing climate,” Moomaw noted. A complementary recent report has identified “stable forests” – natural forests that are not already disturbed significantly – as particularly important to protect as carbon sinks and the many species that these forests hold.

Despite the urgency, Moomaw recommends a targeted approach. “Of course, we need wood and other forest-based resources, and some private forests can be doing just that. But purposefully growing a greater number of natural forests to maximize carbon sequestration is a priority that maximizes many other ecosystem services,” Moomaw said.

For resource production, Moomaw and co-authors promote policies that support longer harvest rotations, higher value/longer lasting products, and a bigger focus on local wood reuse and recycling. Only a small portion of carbon lost from the forest becomes a lasting wood product, and forest manipulations such as clear-cutting, patch cutting, salvage logging, and other approaches can make the land a carbon emitter, potentially for decades. “We need to prioritize proforestation on public land, but we also need to reduce demand and provide education and economic incentives so private landowners let more of their forests continue growing,” Moomaw said. Removing subsidies for large-scale use of wood from forests to fuel heating systems and electric power plants will also reduce pressure on forests, the paper said.

Masino added, “We all know we need to ‘first, do no harm’ to protect our own health, and we immediately need to apply a similar precautionary principle and protection to the natural world wherever possible. All around us, we are still discovering new species and new opportunities.”


More about the authors:

William R. Moomaw, Ph.D., is a climate scientist and Emeritus professor from The Fletcher School at Tufts University. He served as a lead author of five IPCC reports addressing mitigation options. He founded and directed the Center for International Environment and Resource Policy and currently serves as co-director of the Global Development and Environment Institute at Tufts. He is the board chair of the Woods Hole Research Center, a major independent climate research institute, and the North American board of the Climate Group that works with states and regions and multinational corporations to reduce greenhouse gas emissions to meet climate goals. He is now working with forest ecologists and wetland scientists to find the most effective ways to protect and enhance the capacity of these ecosystems to sequester additional atmospheric carbon dioxide and provide greater resiliency to a changing climate.

Susan A. Masino, Ph.D., is the Vernon Roosa Professor of Applied Science at Trinity College. She is a joint appointment in neuroscience and psychology and holds a Ph.D in biology. She is currently a Charles Bullard Fellow at Harvard Forest, working on a research project on forests and brain health in collaboration with Harvard Medical School. She is on the board of the Pinchot Institute, the Hartford County Coordinator for the Old Growth Forest Network, and a member of the Town of Simsbury Open Space Committee.

Edward K. Faison, Ph.D., is senior ecologist as Highstead Foundation in Redding, Connecticut. His work focuses on the role of deer and moose browsing in New England forests, forest history and long-term ecological change, and the synthesis and communication of ecological topics to the general public. He also advises conservation groups, educators, and land trusts with questions about land management and forest monitoring.