Restoring Forests, Part 2

Strategies for restoring degraded forests

In the dry tropical forest zone of Ghana, severely degraded forests resulted from a combination of extractive logging without adequate regeneration and fire and invasion by Chromolaena odorata, a tropical species of flowering shrub in the sunflower family. Photo by U.S. Forest Service.
In the dry tropical forest zone of Ghana, severely degraded forests resulted from a combination of extractive logging without adequate regeneration and fire and invasion by Chromolaena odorata, a tropical species of flowering shrub in the sunflower family. Photo by U.S. Forest Service.

Across the world, an estimated 1 billion acres of forests are in need of restoration, a formidable challenge that will only intensify under continued climate change. Where to start in restoring the world’s forests? What methods are appropriate? Restoring forests, already a complex process, is further complicated—and sometimes stymied—by a basic lack of consensus on what restoration means and how it should be undertaken.

To provide managers with a better understanding of restoration and the factors to consider when planning forest restorations, U.S. Forest Service researchers synthesized the current thinking and available science in two journal articles that explore the paradigms underlying contemporary approaches to forest restoration and outline restoration strategies around specific methods and tools.

Part 1 of “Restoring Forests” addressed the different paradigms that have guided forest restoration. Part 2 focuses on four major approaches to forest landscapes from a functional perspective depending on the starting point, as covered in the second synthesis article by Forest Service researchers.

Community-based restoration using taungya (intercropping with food plants until shade develops from tree seedlings) gave rise to forest-like conditions after 10 years. Photo by U.S. Forest Service.
On the land pictured above, community-based restoration using taungya (intercropping with food plants until shade develops from tree seedlings) gave rise to forest-like conditions after 10 years. Photo by U.S. Forest Service.

“While the focus in many restoration programs has been—and often still is—on restoring stands to some previous, putatively more ‘natural’ state, functional restoration focuses on ecosystem processes, including water cycles, habitat, and ecosystem productivity,” said John Stanturf, Forest Service Southern Research Station senior scientist who led the synthesis effort. “With accelerating climate and land use changes, the functional approach becomes more logical, even more urgent, with the aim towards future adaptation rather than a return to historic conditions.”

The second review article outlines four restoration strategies and synthesizes the science underpinning each:

  • Rehabilitation restores desired species composition, structure, or processes to a degraded ecosystem.
  • Reconstruction restores native plant communities on land recently in other resource uses, such as agriculture.
  • Reclamation restores severely degraded land generally devoid of vegetation, often as the result of resource extraction such as mining.
  • Replacement of species (or their locally-adapted genotypes) with new species (or new genotypes) is a response to climate change.

The article includes an extensive table—a restoration toolbox—that maps out methods and techniques in relation to objectives and present forest conditions, as well as numerous photographs and figures illustrating types of plantings and forest treatments used for different restoration objectives.

“Because the practice of restoration uses many techniques common to silviculture, it’s difficult to draw a line between ordinary forestry and restoration,” said Stanturf. “The distinction may be that extra-ordinary activities are required in the face of degraded, damaged, or destroyed ecosystems.”

For more information, email John Stanturf at jstanturf@fs.fed.us

Read the full text of the article.

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