FORESTS: USDA weighs plan to bring GM eucalyptus to Southeast pinelands (01/29/2010)
Paul Voosen, E&E reporter

Genetic engineering is coming to the forests.

While the practice of splicing foreign DNA into food crops has become
common in corn and soy, few companies or researchers have dared to
apply genetic engineering to plants that provide an essential strut of
the U.S. economy, trees.

But that will soon change. Two industry giants, International Paper
Co. and MeadWestvaco Corp., are planning to transform plantation
forests of the southeastern United States by replacing native pine
with genetically engineered eucalyptus, a rapidly growing Australian
tree that in its conventional strains now dominates the tropical
timber industry.

The companies' push into genetically modified trees, led by their
joint biotech venture, ArborGen LLC, looks to overcome several hurdles
for the first time. Most prominently, they are banking on a
controversial gene splice that restricts trees' ability to reproduce,
meant to allay fears of bioengineered eucalyptus turning invasive and
overtaking native forests.

If such a fertility control technology -- which has come under fire in
farming for fear seed firms will exploit it -- is proven effective, it
could open the door to many varieties of wild plants, including weedy
grasses, to be genetically engineered for use in energy applications
like biomass and next-generation biofuels without fear of
invasiveness.

The use of such perennial plants -- so named because, unlike annual
farm crops, they live and grow for many years -- has long interested
business and government, including the Energy Department, which has
collaborated with ArborGen. The plants, which include many grasses
targeted for cellulosic ethanol, can be harvested when needed and,
given their hardiness, grow on marginal land.

Yet many questions remain about the effectiveness of the fertility
system used by ArborGen, which, according to leading scientists, has
never been rigorously studied in multiyear trials to prove that it can
effectively control plants' spread. More research must be conducted
before such systems are relied upon to restrict pollen and seed
spread, they say.

Despite these calls, ArborGen has been seeking government deregulation
of its eucalyptus, which is primarily engineered to resist freezing
temperatures, since 2008. If successful, ArborGen would likely
revolutionize the timber industry and the Southern landscape by
becoming the first company to roll out bioengineered trees on a
massive scale, observers say.

In its rosiest scenarios, growers using ArborGen's presumably
expensive seeds would see huge gains in productivity and become the
preferred tree stock for a new generation of bioenergy refineries. The
South would become the new Appalachia; timber would serve as its coal.
Inklings of such progress have already arisen, including recent word
that the German utility RWE AG would build the world's largest
wood-pellet plant in Georgia to supplement its coal habits.

By adopting eucalyptus as a tree stock, the United States would simply
be catching up with countries like Brazil, which has leveraged vast
tree plantations in recent decades to pivot from a net wood importer
to an exporter. While the South saw a rise in pine plantations during
this time, pine cannot compete with eucalyptus for sheer growth rate,
the company says.

"The United States is behind the game on this," said Les Pearson,
ArborGen's director of regulatory affairs. "Lots of countries around
the world have been growing eucalyptus for many decades."

Indeed, primarily because of competition from South America, demand
for traditional American tree pulp has gone slack. This sagging
industry could allow up to 10 million acres in the Southeast to be
repurposed for fast-growing eucalyptuses, according to corporate
estimates.

But it still remains unclear if the nascent bioenergy industry will be
enough to make up for demand lost to Brazilian plantations, said
Curtis Seltzer, a timber consultant who has studied ArborGen and calls
its trees a "game changer."

"It's not clear to me that biomass will pick up the slack for the
traditional markets [as they] ebb," Seltzer said. "But it could."

Even given government incentives and a price on carbon, however,
ArborGen must satisfy concerns from regulators and environmental
groups that its engineered trees will not, especially when gifted with
the ability to resist cold, spread untrammeled through forests.

Pollen problems
At its most basic, life is about reproduction. And the species'
struggle to adapt and survive can make attempts to control the
fertility of plants difficult, according to Steve Strauss, a tree
geneticist at Oregon State University who has also consulted with
ArborGen.

ArborGen relies on what has been the most popular system for
restricting plant pollen, which uses a bacterial gene to produce a
toxic enzyme called barnase that slices apart genetic material in a
cell, causing death. Through genetic trickery, the enzyme is only
produced in the pollen-spreading parts of the tree, destroying its
ability to reproduce -- at least most of the time.

Given the number of trees that will be produced, there will likely be
enough genetic instability to allow a very small number of the
freeze-tolerant eucalyptuses to reproduce, Strauss said. Rather than
an absolute containment system, barnase should be thought of as a
mitigation strategy, he added.

"It doesn't mean there are no pollen grains produced," Strauss said.
"Almost nothing in biology is 100 percent."

A tiny number of seedlings are almost assured to escape from the
eucalyptus plantations, Strauss said. But since the trees, in his
evaluation, are unlikely to prove invasive, there should be little
cause for alarm.

"When you talk about trees, storms happen, wind blows," he said. "The
containment is not absolute. There is the chance of some spread. Is it
likely to become an invasive weed? Seems unlikely to me."

Until now, only two of ArborGen's experimental eucalyptus stations
have been allowed to flower, and the company has reported little in
the way of pollen production in the trees. It is now seeking to
greatly expand the number and location of trees allowed to flower to
28 sites totaling 330 acres scattered across seven states. The
Agriculture Department issued a draft approval of the expansion,
subject to public comment, earlier this month.

The modified eucalyptus trees are already planted at most of these
sites, and as they approach sexual maturity, ArborGen has been forced
to pluck the trees' flowers or cut them down completely, causing
millions of dollars in lost research, said Nancy Hood, ArborGen's
public affairs director.

This test acreage is fairly small, hardly the equivalent of a
full-scale commercial planting, as some environmental groups have
accused. (For comparison, there are more than 32 million acres of pine
plantation in the South.) However, ArborGen has confessed that it
hopes USDA will deregulate the trees by the time the cohort reaches
harvest age -- around seven years or so -- allowing the resulting pulp
to be sold.

Many biotech researchers are supportive of the expanded experimental
permit, which will allow more complete studies of the fertility
containment system. While ArborGen has released little in the way of
peer-reviewed research so far, it will publish barnase results this
year, said Maud Hinchee, ArborGen's chief technology officer.

Such data would be a welcome change. While barnase's mechanism is well
documented -- and approved for use in domesticated crops like rapeseed
-- its effectiveness has barely been studied, according to an analysis
written by Strauss in 2007.

"There does not seem to have been any serious field studies, in any
crop, sufficient to estimate the operational effectiveness of
containment genes," Strauss wrote. "Until many such studies are
published, it would be unwise to assume that genes can be fully and
safely contained in the near future."

Decisions to deregulate any wild GM plant like the eucalyptus must
take into account this lack of research, said Hong Luo, a molecular
biologist at Clemson University who has developed a gene containment
system for another wild plant, turfgrass. His team recently completed
a one-year study of the system's effectiveness, he said, but more
research is needed.

"There haven't been really too much studies of what would be impact of
transgene escape from perennials," he said. "We will be cautious in
this respect."

It remains to be seen how the public will react to the concept of GM
forest trees. But as researchers point out, people have already
embraced some engineered trees that have no pollen controls. Almost
all of the papaya trees in Hawaii are genetically engineered to resist
the devastating ringspot virus, and similar efforts are under way to
save the American chestnut, which has been nearly eradicated by fungal
disease.

However, the inability to promise 100 percent containment could delay
the development of bioengineered plants that carry even slight risks
of invasiveness. But such foolproof systems will come, Strauss
predicted.

"I do believe we can produce absolute containment," he said. "We will
be able to do that, I believe, in 10 years. But it's not proven yet."

Australian invaders
The unproven nature of ArborGen's fertility controls is concerning
largely because they will be used to introduce a robust, foreign tree,
conservation groups say. The timber industry has long dreamed of
importing eucalyptus into the South, mimicking Brazil's success, where
plantations transformed the country -- at some environmental toll --
from a timber importer to an exporter within decades.

Previous domestic efforts to establish the tree in the South, which
came to a peak in the early 1980s, failed as winter freezes scythed
dead swaths through experimental plantations. Only in Florida have the
trees survived, though they have only been used in only limited ways,
mostly for mulch. All efforts to move the tree into more temperate
conditions have failed, until now.

Thanks to a plant gene that it licensed from Mendel Biotechnology, a
prime R&D contractor with Monsanto Co., ArborGen's freeze-tolerant
eucalyptuses have been grown in much colder conditions up into the
Carolinas. (ArborGen has many connections to Monsanto, starting with
its CEO, Barbara Wells, who worked at the seed giant for 18 years.)
Mendel's regulatory gene controls the expression of other genes that
influence cold resistance, and its use represents the state of the art
in plant biotech.

But in opening the door to the plant's cultivation, far more scrutiny
is needed as to how eucalyptus will behave when grown in bulk, said
Doria Gordon, a senior ecologist at the Nature Conservancy.

"My concern is about invasiveness. Not that it is a GMO, per se,"
Gordon said. "The concern is, what threat is it to Florida's natural
area and to the Southeast's natural areas?"

Last year, Gordon, who also works at the University of Florida,
evaluated one of the two species used to breed ArborGen's hybrids,
Eucalyptus grandis, also known as the rose gum. The tree had
previously turned invasive in South Africa, Gordon found, which led
her to conclude that the tree carried a risk of turning invasive in
the South, as well.

Gordon serves on a panel that evaluates the invasive risk of plants in
Florida, and last year, the panel classified the rose gum as a
possible invader. Only a few variants of the tree can be grown, it
said, and only with strict management practices, including harvesting
within six months of the onset of flower production -- much sooner
than a forest plantation would like.

Though the rose gum carries an invasive risk, ArborGen's trees are an
unknown quantity, Gordon said. Given the uncertainty involved,
however, the Nature Conservancy has recommended to USDA that ArborGen
be allowed fewer acres and trees to flower, and none in Florida, she
said. The draft permit approved by USDA would allow flowering in 10
sites across the state.

"We don't know if it could become more invasive over time," she said.
And until then, "it would be logical to me to not do those trials in
Florida."

It is not irrational to fear invasiveness in eucalyptus, said Dan
Binkley, a forest ecologist at Colorado State University. However, the
rose gum appears to take on weedy traits only in arid regions like
South Africa, where it can leverage its tremendous water efficiency.
The South is far moister by comparison.

Even in Florida, the eucalyptus has proved to be somewhat delicate,
ArborGen's Pearson added.

The tree "does not exist outside of the planted environment," he said.
And in the closed confines of a plantation, "you need to manage these
things very carefully to let them survive and thrive."

'More Wood. Less Land'
While he would like to see more data on the water use and fire impacts
of eucalyptus plantations, Binkley understands the tree's allure, he
said.

Unlike the pine trees used in Southern plantations -- which have
quietly helped displace tobacco in the region's economy -- eucalyptus
can deploy a full canopy of leaves within a few years. It is greedy
for carbon, and within 27 months can grow to 55 feet in height.

The ultimate benefit of eucalyptus plantations would be the ability to
grow more wood on less land, ArborGen's Hinchee said. (Not
coincidentally, the firm's motto is "More Wood. Less Land.") Forests
are continuously lost to development in the South, and natural
hardwood acres have become harder to harvest. Increased productivity
would have benefits "through the whole economic chain," she said.

Similar claims have been made for the practice of forest plantations
as a whole, which remains controversial despite its ubiquity in the
South, and little data exists to verify the claims.

In the end, if the United States seriously pursues bioenergy from
plants, the country will face a choice of drawing that power more from
trees that are treated like crops, or from grasses, which can behave
far more invasively, Strauss said.

"If we're going to rely on biofuels as a significant part of a diverse
portfolio of renewable technology," then harvesting trees is the best
way to go, he said. "There's a lot of marginal land that could be
used."

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