January 15, 2010
Proponents of genetically engineered trees say the road they’ve chosen will lead to trees capable of weathering freezing temperatures and disease -- trees that can grow more efficiently on less land and possibly serve as a cheap source of biofuel. In addition, supporters say, genetic engineering holds the possibility of bringing some trees back from the brink of extinction.
But critics in the environmental community say the path chosen by the paper industry won’t save a single forest from the chainsaw. They fear that test-tube trees may become invasive, destroying the forests they’re meant to protect.
“There is a lot of hype about transgenics with people fearing that they could be bad in any context,” said Steven Franks, a botanist with Fordham University in New York. “I don’t really think that’s true, that they’re always bad.”
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There are a few scattered plots of genetically modified poplars in the Pacific Northwest, and scientists have used engineering tools to create papaya trees that are resistant to a widespread viral disease. So far, however, genetically engineered trees remain a small-scale industry.
For many environmental groups, the fork in the road for genetically engineered trees is a single species of eucalyptus designed by the corporation ArborGen, a research collective with links to International Paper and other large paper producers.
ArborGen has already planted 300 acres of this eucalyptus, a cross between two Australian natives that the company hopes can better withstand freezing temperatures, across the Southeast U.S. The South Carolina-based corporation is asking the Animal Plant Health Inspection Service of the U.S. Department of Agriculture to let it plant more.
The agency published a draft assessment of this proposal on May 8, recommending approval. But both sides are awaiting a final decision.
What has groups like the Stop GE Trees Campaign worried is that ArborGen will allow these trees to reach reproductive maturity, or flower.
The corporation has taken steps to ensure that the eucalyptuses won’t be able to reproduce. But if some of the trees do manage to disperse, they could begin to encroach into native forests, said Neil Carman, a plant science advisor to the Sierra Club, which has joined the campaign.
Wayward bees could also take pollen from the genetically engineered trees to unmodified eucalyptuses planted for pulp nearby, potentially crossbreeding the two, Carman said.
“It’s very risky ecology to be putting out a perennial tree like this,” he said. “Once it escapes, that’s it.”
The tall and fragrant eucalyptus is no stranger to controversy. This group of trees is infamously fire-prone and requires large amounts of water to grow.
Several species of eucalyptus have checkered pasts in the United States, Carman noted. The Californian Invasive Plant Council, for instance, considers the bluegum eucalyptus, a common fixture on the Californian coast, an invasive weed.
ArborGen currently has seven acres of flowering eucalyptuses, which the USDA permitted under a previous assessment.
These plots aren’t for commercial harvest yet. ArborGen scientists are using them to test the performance of a single gene, according to Maud Hinchee, ArborGen’s science advisor.
In genetic engineering, scientists zoom into the DNA of a developing embryo. They cut the genetic code embedded in this swirling mess with enzymes that work like microscopic scissors. From there, scientists can modify these organisms by adding foreign DNA or blocking unwanted genes.
Genetic engineers can also reignite old pathways that evolution has switched off. The gene that helps eucalyptuses weather stress and cold temperatures belongs to one such pathway, Hinchee said.
Fears that this freeze-hardy tree will make a break for it are exaggerated, according to Hinchee. Hybrid trees are lightweights when it comes to reproduction. They rarely produce viable seeds with members of related species or with their own, she said.
“The tree, because it’s a cross between two species, it’s not very productive reproductively,” Hinchee said.
But predicting a backlash from environmental groups, scientists went into the tree’s DNA to try to completely block pollen formation, she said.
In its draft environmental assessment, the USDA agreed that the risk of reproduction within ArborGen’s test plots or of crosses with unrelated eucalyptuses nearby is small.
But freak accidents are the hallmark of evolution. Eucalyptus trees are long-lived, prolific seed producers and, like all living things, prone to behavior-changing mutations, said Franks, who is also a former employee of the USDA’s Invasive Plant Research Lab in Florida.
“Given a long enough period of time,” Franks said, “these small probability events do happen. With the tiny seeds, the chance that one of the millions and millions would get carried away a fairly long distance and survive could happen.”
But Franks emphasized that the USDA enforces regulations and conducts extensive research to prevent the escape of genetically modified plants.
Conservationists should decide on a species-by-species basis if the benefits of genetic engineering outweigh the risks, Franks said.
No matter how careful corporations like ArborGen are, there are a small number of people who will never accept the technology, said Steven Strauss, a professor of forest science at Oregon State University.
“They have a powerful vested interest in seeing things differently,” Strauss said. “They are fundamentalist in their views.”
Strauss, who uses genetic engineering to study natural tree populations with partial funding from ArborGen, highlights its potential to help threatened forests.
These applications go beyond efficient growing practices. According to Hinchee, ArborGen is exploring ways to reduce the amount of a substance called lignin in its trees, making them easier to process and turn into biofuel.
With grants from ArborGen, scientists at the University of Georgia and the State University of New York are using genetic modification tools to rescue the American chestnut from a decimating fungal blight. These scientists snip fungal resistance genes from closely related Chinese chestnuts, planting them in American chestnut DNA.
Genetic engineering tools “are valuable as part of an integrated program that incorporates a traditional breeding program,” says Scott Merkle, professor of forestry and natural resources at the University of Georgia. “All of us are going to work together on this.”
Strauss said that genetic engineering may be the only way to feed growing demand for products like paper without completely destroying natural forests.
“If you look at the big picture of world consumption,” Strauss said, “the only way we’re going to make advances is to take some calculated risks.”
But Franks said the idea that genetic engineering will help save the world may be overblown. He thinks trees, even genetically engineered trees, will likely be too costly to process to make efficient biofuel. As for consumption, the problem isn’t a lack of technology but a problem with how food and materials are distributed.
“How much is that really going to help the problems that we really have--getting the materials, getting the food that we need?” he said. “We already produce enough food to feed everybody in the world but yet a billion people go hungry.”
Anne Petermann, a co-coordinator of the Stop GE Trees Campaign, said ArborGen’s sustainability claims are a “gross misrepresentation” of its aims.
“They’re not actually putting in plantations to protect forests,” Petermann said. “They’re putting in plantations where forests used to be.”
For people like Petermann, the benefits don’t outweigh the cons. She and other environmental activists are concerned that if the USDA allows ArborGen’s test plots, it will open the door for a host of other commercial genetically engineered trees.
If we start down that road, Petermann said, we might never be able to turn back.
Daniel Strain is a graduate student in the Science Communication Program at the University of California, Santa Cruz