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Does Restoring the American Chestnut Require Greater Risk Than Reward?

Melissa Holme


  • Addresses the widespread decline of the American Chestnut tree.
  • Discusses the potential challenges and pushbacks of introducing genetically engineered Chestnut trees.
  • Explores why genetically engineered Chestnut trees are not the solution to the restoration of the American Chestnut tree.
Does Restoring the American Chestnut Require Greater Risk Than Reward?
SolsticeSol via Getty Images

Before the mid-20th century, the American chestnut tree used to dominate the East Coast of the United States. The American chestnut, reaching staggering heights of 150 feet, was known as the redwood of the East and played an equally pivotal role ecologically and socially as their West Coast counterparts. Early Native American tribes used the tree as a medicinal and food source, and early Appalachian communities harvested chestnuts, using it for both their own food and their livestock’s food. Moreover, tannins from the wood were used for leather processing and the rot-resistant wood built the foundations of 19th- and 20th-century homes. Ecologically, the American chestnut was a dominant tree of its Appalachian range, with researchers estimating the tree compromised 25 to 50 percent of forest cover in its range.

The importance of the chestnut tree made its widespread decline that much more painful. In the late 19th century, a fungal parasite called Cryphonectria parasitica, thought to have originated on the Asian continent, was brought over on imported ornamental Japanese chestnut trees in 1876. In 1904, the Bronx Zoo reported cankers on their chestnut trees, and the parasite swiftly spread down the East Coast. Within a few decades, the parasite wiped out almost the entire chestnut tree population. The parasite’s presence would work tree-by-tree down the coast, appearing first as a canker, which would then burst and kill the tree from top down. And while the blight does not kill off the chestnut’s root system, this offers little hope. Though “an estimated 430 million wild American chestnuts still grow . . . most survive only five or 10 years before the blight gets them too."

Despite community and government action, the blight killed “nearly 4 billion American chestnuts across some 300,00 square miles.” Its decline also led to the decline of oak trees in Southern Appalachia, as well as a decline of reliant wildlife species such as the Allegheny Woodrat and eastern wild turkeys. The tree had a cascading effect on its local food chains, affecting mammals, insects, and local water quality; and the American chestnut moth soon went extinct as the tree’s most reliant species.

The chestnut blight did not go unnoticed in forest management regulations. The Healthy Forest Restoration Act of 2003 required the secretary of the U.S. Department of Agriculture (USDA) to develop an “early warning system” to prevent potential forest epidemics, specifically citing the American chestnut blight as one that resulted in environmental and economic devastation. In the Forest Service’s Final Draft of the Early Warning System, the agency sets up a framework for an early warning system, again citing specifically to the chestnut blight when discussing the agency’s cooperative restoration efforts to restore the tree.

One of these cooperative efforts included an Memorandum of Understanding (MOU) with the American Chestnut Foundation (ACF) to “establish a framework for cooperative research and management activities necessary to maintain and enhance the eastern forest ecosystems by reintroduction of blight-resistant seedlings of Castanea dentata, or American chestnut.” The MOU establishes that the Forest Service will make national forest land available and provide assistance to the ACF’s breeding and restoration efforts to establish a healthy chestnut population in its native range. The ACF, working with Forest Service funding, has been breeding American chestnuts with more blight-resistant Chinese varieties to develop a hybrid tree that could potentially thrive in the tree’s former region.

However, one of these restoration efforts has garnered controversy. Recently, the USDA prepared a Notice of Intent to Prepare an EIS for the petition for a deregulated status for a blight resistant American chestnut tree, known as Darling 58, developed by the State University of New York. The tree is genetically engineered (GE) to release an enzyme that fights the fungal pathogen Cryphonectria parasitica, otherwise known as chestnut blight. This varies from traditional efforts, like that of the Forest Service, to use breeding to develop more blight-resistant trees.

In short, allowing the petition to move forward would result in the GE-tree gaining nonregulated status. Currently, the USDA is required to regulate the importation, interstate movement, or release of genetically modified organisms. Allowing for nonregulated status would allow for public distributionof seedlings to be planted in the chestnut’s native range. Importantly, this would mean releasing the seeds to the public without recordkeeping or reporting requirements about the tree’s development. If the deregulation petition is approved, Darling 58 would be the first genetically engineered tree approved in the United States and the first GE plant intended to grow in the wild.

While the project does present the possibility of reintroducing a blight resistant American chestnut, the petition faces stiff opposition. Experts are worried about the risks of introducing a GE tree into the wild, especially running the risk of its genes spreading further than intended and having a detrimental ecological impact. Moreover, the group seeking to publicly distribute the GE-Chestnut has a startling lack of long-term and accurate data. Moreover, Indigenous environmental justice activists have also expressed concerns over the introduction of GE chestnut trees, citing a lack of consideration of tribal sovereignty in the decision-making protocol for the tree’s release.

GE chestnuts may also face legal challenges if the petition moves forward. GE eucalyptus trees may offer insight into the GE chestnut’s future. In 2010, the USDA-APHIS granted numerous permits for open-air field tests of genetically engineered eucalyptus engineered to increase cold tolerance, decrease fertility, and decrease lignin biosynthesis. Allowing open-air testing meant the potential for the GE-eucalyptus to pollinate nearby non-GE trees. After a lawsuit by various environmental groups for a failure to analyze the eucalyptus’ impact, the USDA conducted an environmental analysis under the National Environmental Policy Act for the permits’ renewal, but issued a subsequent Finding of No Significant Impact. In 2017, the USDA released a draft Environmental Impact Statement (EIS) seeking comments for the same deregulation status that the GE-chestnut seeks, allowing a larger commercial use of the GE-eucalyptus tree. The project has faced protests, investor criticism, and thousands of public comments urging USDA to reject the proposal. The USDA has not released its final EIS yet.

Like the GE-eucalyptus, a deregulated GE-chestnut could face potential NEPA claims, but concerningly, the Forest Services' use of a GE-chestnut may allow a quicker route. The Forest Service has a categorical exclusion to NEPA for the “regeneration of an area to native tree species,” meaning the agency does not have to conduct the typical environmental analysis for this type of activity. Specifically, the exclusion references “planting seedlings of a superior trees in a progeny test site to evaluate genetic worth,” meaning that this categorical exclusion could potentially apply to genetically modified chestnut trees introduced into national forest land. Additionally, the ACF, with whom the Forest Service holds a MOU concerning Chestnut restoration, has come out in support of the GE-chestnut. Using both the Forest Service’s categorical exclusion criteria and the existing relationship between the agency and the ACF could mean a swift introduction of GE chestnuts onto national forest land.

The loss of the American chestnut was ecologically devastating, and restoration efforts should be continued to try to restore the tree to its former population. However, introducing commercially available genetically engineered chestnut trees is not the answer. Genetically modified trees are unsustainable models of forest management, leading to unchecked spreading of a GE chestnut that lacks the proper long-term, real-world studies to guarantee its safety. The American chestnut tree should be restored, but not without sacrificing the environment.

For more about the American chestnut, please see Will Genetically Engineered Chestnuts Be Roasting on an Open Fire of Litigation?