GMO trees have ignited a flurry of
renewed debate.
By Kelly Kagamas Tomkies
for Office.com
As if "Frankenfoods"
aren't enough of a concern for biotechnology opponents,
now it's "Frankenforests" that are emerging as
a major concern among increasingly vocal activists. Genetically
engineered trees that express certain potentially
desirable traits are being studied in the United States,
Israel and Canada. One of the goals is to develop trees
that would be more productive and more environmentally
friendly.
But, as with many areas
of biotechnology, environmental and consumer groups are
voicing concern about the possible long-term effects
such trees may create, especially given their size, long
life and role in the world's ecosystem.
Office.com asked Scott
Harding, Ph.D., professor of forestry at Michigan
Technological University in Houghton, Mich.; Margaret
Mellon, Ph.D. and J.D., director of food and
environmental programs for the Union of Concerned
Scientists; and Steve Strauss, Ph.D., professor of
forest science and genetics at Oregon State University,
about the potential benefits and risks behind this
developing science.
What are the
potential benefits or desired traits of genetically
engineered trees?
Harding:
The major research to date has been to reduce a compound
that occurs in trees called lignin. When lignin is
manipulated it means a reduction in the chemicals used
in creating pulp for papers.
There are some studies
to reduce cellulose, as well, and a small group is
interested in sterilization — controlling the
flowering on trees to prevent them from cross-breeding
with indigent trees.
There are also trees
being genetically engineered to be pest- and
pathogen-resistant and to prevent wood decay.
Mellon:
What I understand is that trees are being engineered to
grow faster and produce more woody pulp.
It certainly seems to
me that nothing I've read is a compelling benefit that
we would be hard-pressed to do without. We need to ask
the questions about what might go wrong.
Strauss:
The biggest benefit is producing trees that grow more
wood and have less environmental impact and are grown on
less acreage.
The demand for wood is
growing rapidly despite our use of recycling. The goal
is to increase productivity per acre of intensively
managed land — land that is set aside.
There are diverse ways
to approach this: creating trees that have herbicide
resistance, less soil erosion and tillage traits.
Another general area of study is trees that are designed
to have more desirable processing traits, like
manipulating lignin. Small changes in lignin mean a
significant decrease in chemicals used to process paper
and can add up to big economic and environmental
benefits.
Some are interested in
modifying the flowering — getting the trees to flower
when you want them to so you can breed them more easily
or produce nonfunctional flowers to avoid spreading
traits. I am also a population geneticist and I know
there has been talk of "super trees." We don't
have the knowledge yet to produce anything like that,
and as long as we don't make any obviously unintelligent
moves like enhancing a tree that is already
pest-resistant, there is not a significant possibility
of producing "super trees."
Has the USDA
reviewed the research done on trees thus far?
Harding:
You have to. It is required, especially if you are
field-testing, normally at the beginning, and if you are
an academic institution and you are receiving government
funding. In that situation, you will have to go through
a peer review at the USDA.
"What
we hope to do is control manipulation before it is
released into the environment."
— Scott
Harding, Ph.D.
professor of forestry
Michigan Technological University
There has been some criticism of the
governmental oversight — that we do not have enough
knowledge to say "here's a set of rules saying what
can and can't be manipulated." But what we hope to
do is control manipulation before it is released into
the environment.
Mellon: The USDA is overseeing
the field-testing using the same rules they use for
annual plants, which are not adequate. No agency or
company has attempted to commercialize any tree product
but, so far, the agency doesn't appear to be on top of
it.
Mellon: From what we know, they
are not ready to approve trees for commercial use on any
scale. We need to take it slowly. Forests are very
important, and there are a multitude of services there.
We need to think hard before we take risks, and be sure
the benefits are worth the risks.
Strauss: Yes, researchers are
in close contact with the regulatory agencies that
require safety information. Field trials are conducted
with close contact with state and federal examiners who
make a site inspection. They make sure the site or trees
are contained physically — either the trees are killed
before they flower or they make sure they are in no
danger of spreading.
We are moving slowly and carefully. We
have been researching these trees for the past 15 years
and the most advanced studies are only in the third
generation. The agencies are looking more carefully at
the trees because they live a long time in the
environment — they are going under a lot of scrutiny
by the USDA and EPA.
The goal of biotech trees is to make
them more productive, producing a product desired by
people.
What are the potential long-term
effects and would these trees affect other species?
Harding: There are general
concerns of bioengineering in the environment no matter
what the particular change in the tree is. Somewhere
down the road, some unknown consequence may occur. The
research to control flowering addresses that.
To my knowledge, nothing (no
genetically modified tree) is close enough to put on the
market. They are nowhere near ready for the mass market.
I think once they become closer to becoming ready, then
there may be more specific concerns.
One of the things that will be looked
at is interactions with insects. A mass change in the
climate could make all trees susceptible. People will
try to model that in field studies. We don't want to
produce trees susceptible to insect infestations — a
reasonable hypothetical issue — or engineer trees too
tough for insects that may be a necessary part of the
ecosystem.
These issues are impossible to predict
now, but need to be investigated.
Mellon: We don't know the
long-term effects, and it is more difficult to find out
in trees when they live for 20 to 30 years. The ability
to test to find out what might go wrong is impeded. It
is hard to devise tests because of the long-term nature.
If something goes wrong it could be long after the
people that sold or planted the trees are off the scene.
The important thing to worry about is
how long they live in contrast to annual plants. One set
of concerns is cross-pollination. For example, if a tree
is equipped to resist pests, it won't just be that plant
that will carry the trait.
It's a scientific challenge to think
through the multistep scenarios. And where will the
trait be expressed? Only where pests cause damage, or
all over? in pollen? What range of trees could be
affected: identical species or those closely related?
"We need to
learn in a very thoughtful way what might go wrong and
then balance these against the proposed benefits very
early to know whether the benefits outweigh the
risks."
— Margaret
Mellon, Ph.D., J.D.
director of food and environmental programs for
the Union of Concerned Scientists
We need to learn in a very
thoughtful way what might go wrong and then balance
these against the proposed benefits very early to know
whether the benefits outweigh the risks. We are just at
the beginning of answering those questions.
Strauss: We have a project here
funded by the USDA that is a risk assessment program
thinking of the long-term effects. We are using poplar
trees because they are like the lab rat for biotech
trees, and we are using computer models and field
studies to logically predict what might happen.
Forestry takes biotech one step
further than ag biotech does because we use adaptive
management as a means to intelligently find a good way
to go forward, measuring the progress along the way. We
do an assessment down the road and perhaps change track.
No one would cover the world with one
type of tree that is not an economical or ecologically
efficient method. Instead, we would develop strategy to
find the most ecologically efficient means based on
studies of the pest population.
Other issues are what is the
biodiversity level and how the economical and ecological
views look. We do research every step along the way,
assessing as we go.
Some environmentalists are concerned
with "super weeds"; but I don't see that there
is a potential. But it is being discussed and analyzed.
I doubt that we could create a weed that is so powerful
it overwhelms the controls in nature.
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