By Chelsea Harvey

Special to The Washington Post

A genetically engineered, freeze-tolerant eucalyptus tree is moving closer to receiving approval from the U.S. Department of Agriculture, amid concerns about the tree’s possible negative effects on the environment.

The USDA has proposed lifting restrictions on commercial production of the trees, based on a draft environmental impact statement that concluded the trees pose few significant environmental risks. Planting the trees would “either not differ or may be slightly worse from those caused by the cultivation of planted plantation pine,” the report said.

Brazil approved a genetically modified eucalyptus, created by biotechnology company FuturaGene, for commercial growth two years ago. But this would become the first genetically engineered tree approved for commercial use in the United States.

The announcement comes six years after forestry and biotechnology firm ArborGen filed a petition for deregulation with the USDA, and more than a decade after it began field testing the trees in the United States.

It’s unclear when the final decision on the trees will be made. The agency is considering public comments, and it still needs to confer with the U.S. Fish and Wildlife Service on the tree’s potential impact on wildlife.

“If there are no new significant issues or information that’s relevant to the environmental impacts, that would require any substantial changes, then we’ll finalize the environmental impact statement and send it on [to the Environmental Protection Agency] to publish,” said Richard Coker, a legislative and public affairs specialist with the USDA’s Animal and Plant Health Inspection Service. If substantial new information about the trees is discovered in the public comments, the agency may reconsider its recommendation to approve the trees.

The USDA has projected in its environmental impact statement that about a million acres of pine plantations could be replaced with the eucalyptus trees, if it wins approval.

The company suggested that the genetically engineered trees could help feed global demand for biomass energy at a time of growing concern about climate change.

But environmental groups say the tree uses excessive amounts of water, increases wildfire risks, and could turn into an invasive species.

And scientists argue that biomass energy produces no climate benefits.

Fast-growing trees such as eucalyptus can grow and be harvested in less than a decade — but even then, it could take years to make up for the carbon released by clearing out the slower-growing, carbon-rich tree plantations they would be replacing.

Eucalyptus trees are native to Australia, and have become a popular choice for wood-pulp plantations because of their quick growth rate, particularly in warm climates such as Brazil and southern Africa. The trees are ready for harvest in five to seven years.

But in the southeastern United States, winter temperatures can become too cold for conventional eucalyptus. Plantations are dominated by native pines and slower-growing hardwoods, which can take several decades to reach maturity.

ArborGen says its trees are capable of withstanding temperatures as low as 15 degrees Fahrenheit. It says the trees can ease the demand for hardwood, while continuing to expand U.S. exports of wood pellets and other biofuels. The company did not respond to requests from The Washington Post for comment.

Wood pellet exports doubled between 2012 and 2013 in response to growing demand in Europe, according to the U.S. Energy Information Administration. In 2015, the United States was the world’s largest exporter of wood pellets, according to the U.N. Food and Agriculture Organization.

ArborGen petitioned the USDA in 2011 to grow the trees for commercial purposes. After a number of studies, the USDA released its draft environmental impact statement in April, indicating it was likely to approve ArborGen for commercial production.

But environmental groups collected thousands of comments opposing the trees during the public comment period that ended July 5.

Environmental groups have outlined a number of objections — in addition to climate concerns.

Beverly Law, a forestry expert at Oregon State University, said eucalyptus trees produce a highly flammable oil, as well as a high volume of leaf litter, which makes them a higher fire risk.

Earlier this summer, Portugal limited the planting of such groves after more than 60 people were killed in a deadly wildfire, widely believed to have been exacerbated by the prevalence of eucalyptus trees.