Now, Bioengineered Trees are Taking Root
Transgenic Poplars Could Make China
a Big Player in Lumber.
But some experts worry about effects on nature.
MARK CLAYTON / The Christian Science Monitor 10mar2005
Scattered across at least seven provinces in China are more than 1 million common poplar trees with an uncommon bite. They can kill the insects that nibble their leaves. Their unusual defensive system is a genetically engineered bomb: Bacillus thuringiensis, or Bt, a naturally occurring toxin inserted into the tree's DNA. Other such transgenic species, such as the larch and walnut, are in the works, Chinese researchers report.
Such moves are shaking up the twin worlds of forestry and environmentalism. Transgenic trees are reaching the threshold of commercialization - a point bioengineered crops reached in the 1980s, observers say. This time, though, it's not the United States leading the charge, it's China.
Though little reported in the West, China's swan dive into large-scale transgenic forestry is essentially the first commercial-scale deployment of genetically engineered (GE) trees in the world, experts say. That could one day mean a potent new competitor to the lumber and paper industries. It also may mean that cutting-edge GE tree research in the US will fall behind, hobbled by regulation and public protest. It also puts decisions about a controversial - and, some say, potentially dangerous - technology into the hands of an authoritarian government, with less oversight and fewer technical controls than in the West.
"What the Chinese have done, planting [genetically engineered] trees across hundreds, maybe thousands, of acres, hasn't been done anywhere else in the world," says Yousry El-Kassaby, a forest geneticist at the University of British Columbia in Vancouver. "It marks a shift in the center of gravity away from the US, where there's a lot of genetic engineering tree research, but much of it is restricted to the labs or very regulated small field trials."
The case for GE trees seems straightforward. Faster-growing species can produce more lumber and paper in shorter time, which makes them a cheaper raw material. Supertree plantations could also mean less disturbance of natural forests - an environmental plus.
Scientists can "develop faster-growing trees, trees that produce more biomass that can be converted to fuels, and trees that can sequester more carbon from the atmosphere or be used to clean up waste sites," said Spencer Abraham, then US secretary of Energy, last fall.
Proponents also tout the technology as something that can be used to return vanishing species such as the American chestnut to the American landscape, by modifying its genetic makeup to defeat a devastating blight.
A problem with pollen But there's a big catch, experts warn. Trees are perennial plants that produce large quantities of pollen released far higher into the air than ordinary crops. This "gene drift" in crops has caused problems as large seed companies have sued US and Canadian farmers for illegally using GE seeds. The farmers claimed their crops were contaminated by drifting pollen, but to no avail. A study last year by the Union of Concerned Scientists found that seeds of traditional varieties of corn, soybeans, and canola "are pervasively contaminated" with low levels of DNA from genetically engineered varieties of those crops.
If DNA can spread so broadly from GE crops a few feet high, there's no telling what will happen with pollen from trees 50 to 100 feet high or more, experts say. For example: Pollen from GE conifer trees can blow more than a thousand miles, new research at Duke University shows.
The potential for genetic contamination of forests - and potential rewards from using GE trees - are enormous, experts say. "For the first time, we have the ability to put a bacteria or even a fish gene into a tree," says Robert Jackson, professor of biology and director of Duke University's Center on Global Change. "Some make that a moral issue. Is it morally right? Another question is: Is it smart - or, maybe, is it dangerous?"
Indeed, the idea of releasing GE trees into the wild sends shudders through Alyx Perry of the Southern Forests Network, a coalition of loggers, landowners, and environmentalists. "Our conclusion is that the genetically engineered trees will inevitably contaminate nongenetically engineered stands of trees."
That, in turn, could lead to millions of acres of infertile private timber, possibly lacking enough lignin (a wood-strengthening substance) needed to be saw timber, Ms. Perry says. Combined with internal pesticide production in pine and poplar trees in the wild, it could lead to forests unable to reproduce, produce food for animals, or create marketable timber.
In the US, at least 69 field-test permits are in effect for three GE tree species - pine, poplar, and walnut. Most of those occupy two acres or less, says the US Department of Agriculture. Under USDA rules, such trees are closely monitored and not permitted to reach the flowering and pollination stage. So far, just one GE variety, a Hawaiian papaya, has been approved to be grown commercially. But commercialization is moving forward. In January 2004, the USDA announced its "intention to update and strengthen" biotechnology regulations for GE organisms, which some say is a key shift. And field research trials for GE trees in the US, including those conducted by ArborGen, a forestry-research firm in Summerville, S.C., have surged since 1997. ArborGen has been approved to conduct dozens of field trials with pine and poplar species genetically engineered for altered fertility, lignin levels, and other features, USDA database records show.
"We certainly see that genetic engineering in a plantation setting ... could play a big part in meeting world demand," says Les Pearson, ArborGen's director of regulatory affairs. ArborGen's first tree is at least seven years away from commercialization, he adds. Others see GE trees coming sooner.
"Government and industry are basically looking at what they can do to finalize regulations to streamline commercial release," says Neil Carmen of the Sierra Club. "We're talking about potentially millions of acres of genetically engineered trees."
Insight from papaya At least two other transgenic tree species, a plum and another papaya, are undergoing USDA review. More than 30 species of GE trees - including 20 species valuable for timber or paper and pulp - are being developed, Dr. Carmen says. Ironically, Hawaiian farmers say the approved GE papaya has already contaminated groves, he adds.
"The regulation of this whole thing is lagging the technology," says Roger Sedjo, director of the forest economics and policy program at Resources for the Future, a Washington policy think tank. "A lot of countries are pursuing research in the area and some of it is coming to fruition. What we don't have is a global standard."
In Brazil, for example, researchers have embarked on large-scale research to develop a GE eucalyptus tree. The idea is to make the slow-growing Australian native mature faster and resistant to disease.
"We're certainly not ready to understand all of the risks yet," says Duke's Dr. Jackson. "There is immense commercial pressure to move ahead with this. And frankly, it's pretty easy to outline the economic benefits, but much more difficult to outline the long-term costs and what they will be - and how long they'll last if things go wrong."
A forest of facts Trees are the world's largest and oldest plants. They cover nearly a third of the world's land surface (excluding Antarctica and Greenland). They blanketed two-thirds of the surface before humans began to farm.
• The double-coconut palm in the Seychelles boasts the largest tree seed: 50 pounds.
• California boasts the world's tallest trees, the redwoods, and the oldest, bristlecone pines. The former can grow 360 feet tall. The latter have been known to live more than 4,000 years. The average city tree lasts eight years.
• By turning carbon dioxide into oxygen, trees replenish the atmosphere. Two mature trees can produce enough oxygen for a family of four.
• Over one year, a tree can absorb the carbon created by a car driven 26,000 miles.
Sources: World Book; United Nations; Earth Policy Institute; International Society of Arboriculture
source: http://search.csmonitor.com/2005/0310/p14s02-sten.htm 10mar2005