ISIS Report 28/02/05
GM Forest Trees The Ultimate Threat
Genetically modified (GM) forest trees do not attract the same
immediate health concerns as GM food crops. But in reality, they pose an even
greater threat because they impact directly on natural forests that are
essential for the survival of our planet.
Dr. Mae-Wan Ho and
Prof. Joe Cummins
A fully referenced version of this article is posted on
World status of GM forest trees
Most genetic modification of forest trees have been done by
Agrobacterium-mediated DNA transfer; but bombardment with DNA-coated
particles, or biolistic transformation, has also been used. Of the
205 permit applications listed at the end of 2003, 73.5% originated in the USA,
23% in other OECD member nations (in particular, Belgium, Canada, France,
Finland, New Zealand, Norway, Portugal, Spain and Sweden) and 3.5% elsewhere
(Brazil, China, Chile, South Africa and Uruguay). Four traits account for 80%
of the permit applications: herbicide tolerance (32%), marker genes (27%),
insect resistance (12%), and lignin modification (9%). Of the tree species
involved, Populus, Pinus, Liquidambar (Sweet Gum Tree) and
Eucalyptus account for 85% of applications.
Although commercial interest was low during the first ten years of GM
trees development, it has steadily increased since the late 1990s. By the end
of 2003, 45% of the permits submitted were from industry, mostly for transgenic
poplars. But to-date there has not been a concerted push for commercialisation
of GM trees except in China, where more than one million GM trees have been
planted in "reforestation" initiatives since commercialisation was approved by
The Chinese State Forestry Administration in 2002 (see "GM trees get lost", this
Several companies, including Weyerhaeuser, Shell and Monsanto, at one
time involved in GM tree research have since pulled out because it was not
economically attractive. However, the decision reached in December 2003 at the
ninth Conference of the Parties to the UN Framework Convention on Climate
Change to allow Northern companies and governments to establish plantations of
GM trees in the South under the "Clean Development Mechanism" might be the
subsidy that GM proponents need to make GM trees seem economically attractive.
The overriding importance of forests
Forest trees are long-lived. Their root system is extensive, interacting
with countless species in the soil biota that are crucial for recycling,
storing and keeping nutrients within the forest ecosystem.
Above ground, forest trees provide shelter, home and food for indigenous
peoples and between 1.5 to 2 million species of insects, birds, mammals, other
plants, epiphytes, fungi and bacteria.
All human beings are dependent on forests in one way or another, for
clean water, habitat, food, medicinal plants, and as recreational and spiritual
Most of all, forests, especially the tropical rainforests, are essential
for the water cycle that brings rain to crops; and for regulating the
temperature of the earth, preventing places from getting too hot or too cold.
Forests absorb carbon dioxide and produce oxygen; in that respect they are the
lungs of the living earth (see "Why Gaia needs rainforests",
Losing forests to GM tree plantations would spell ecological disaster
for our planet, especially as global warming is fast accelerating.
GM trees anathema to forest ecosystems
GM trees are designed for large monoculture plantations anathema to the
bio-diverse natural forest ecosystems. Local peoples names for industrial
tree plantations are revealing. Eucalyptus is the "selfish tree", because
eucalyptus plantations remove nutrients from the soil and consume so much water
that farmers cannot grow rice in neighbouring fields. Mapuche Indigenous People
in Chile refer to pine plantations as "planted soldiers", because they are
green, in rows and advancing. In Brazil, tree plantations are "green deserts",
and in South Africa, "green cancer". Throughout the Global South, organisations
and networks are actively opposing industrial tree plantations on their land.
GM trees will intensity both the problems of industrial plantations and the
opposition from indigenous peoples.
A joint report by the World Rainforest Movement (WRM) and Friends of
the Earth International (FoEI) says that the scientists claiming to "improve"
trees by genetic modification are in reality working to "improve the
profitability of the businesses" funding their research (http://www.wrm.org.uy/subjects/GMTrees/text.pdf).
"But from a biological perspective there is no improvement whatsoever.
Is a tree with less lignin better or worse than a normal one? It is clearly
worse, given the resulting loss of structural strength which makes it
susceptible to extensive damage during wind storms. Is a herbicide-resistance
tree an "improvement"? It is not, for it allows extensive herbicide spraying
that affects the soil on which it stands, at the same time as it destroys local
flora and impacts on wildlife. Is a flowerless, fruitless and seedless tree of
any use to living beings? It does not provide food to myriad species of
insects, birds and [other] species that depend on these as food. Is a tree with
insecticide properties an improvement? It is a dangerous hazard to many insects
species, which are themselves part of larger food chains."
GM trees violate international conventions
The WRM report points out that GMOs in general and GM trees in
particular, are a clear violation of the Convention on Biological Diversity,
which obliges governments to take a precautionary approach towards GMOs that
may cause serious damage to biodiversity. GM trees also violate the spirit of
the United Nations Forum on Forests, which was set up to protect the
Unfortunately, the inclusion of GM trees within the framework of the
Kyoto Protocols Clean Development Mechanism means that the Climate Change
Convention not only supports the expansion of monoculture tree plantations, but
GM tree plantations supposed to act as better "carbon sinks".
The WRM and FoEI International are calling on all governments,
especially the Parties to the Framework Convention on Climate Change and its
Kyoto Protocol, to ban the release of GM trees. The campaign to ban GM trees
was launched in January 2004 by the Finnish Peoples Biosafety Association
and the Union of Ecoforestry (see "No to GM Trees",
Transgene contamination inevitable and unavoidable
Forest trees are tall, long-lived and produce abundant pollen and seeds
that can be carried far and wide. Forest trees also reproduce asexually,
sending out clones that spread long distances from the mother plant, thus
promoting further transgene contamination. Contamination of native trees by GM
trees is hence inevitable and unavoidable.
Low lignin GM trees increase destruction of forests &
Low lignin trees are more susceptible, not only to storm damage but also
to attacks by insects, fungi and bacteria (see "Low lignin GM trees and forage
The reduced-lignin trait spreading to native forest trees will make them
susceptible to storm, attack by pests, and fungal and bacterial diseases.
Insect pest populations will also increase as a result.
While low lignin GM tree plantations may benefit the paper industry,
they will destroy local livelihoods, forcing people to move away, some of them
to new forests where they clear more land for farming. Tree plantations often
follow the destruction of native forests. In Sumatra, for example, vast areas
of forests have been cleared to feed pulp and paper mills; the clear-cut
forests being replaced by acacia plantations.
The argument that planting faster growing GM trees is "growing more wood
on less land" is misleading. Producing more fibre for the pulp industry will
not change the demand for high quality decorative tropical hardwoods for the
construction industry, which come largely from native forests. Also, the demand
for timber is not the only cause of deforestation; road-building, dams, cash
crops (such as soya in Brazil and Argentina) or cattle ranging, mining and oil
extraction all contribute to destroying native forests, and creating GM tree
plantations will do nothing to stem the destruction.
Fast growing GM trees will consume even more water than current
industrial tree plantations, draining the already depleted aquifers and
impacting on surrounding forests.
Most of the pulp produced in the South is exported to the North. Per
capita paper consumption in Germany is 70% that in the US. Vietnam consumes on
average 2% of the amount of paper consumed in the US, despite the fact that
literacy rates in the US, Germany and Vietnam are almost identical. Nearly 40%
of the paper is used for packaging, and 60% of the space in the US newspaper is
taken up by adverts. According to Jukka Hamala, CEO of Stora Enso - the second
biggest paper, packaging and forest products company in the world, whose sales
totalled 12.4 billion in 2004 - the key factor in increased paper demand was
increased spending on advertisements in newspapers and magazines. Thus,
increasing paper consumption is neither necessary nor desirable.
Fast growing GM trees exacerbate climate change
The argument that planting GM trees can reverse climate change is also
fallacious. Japanese car manufacturer Toyota started field trials of trees
genetically modified to absorb more carbon in 1993. Unfortunately, while carbon
absorption increased, it was accompanied by a dramatic increase in water
Tree plantations are much less effective in sequestering carbon than the
native forest ecosystem. The biodiverse native forest ecosystem is an effective
carbon sink. It has been estimated that the neo-tropical forests of Central and
South America sequesters at least one tonne of carbon per hectare per year in
biomass increase above ground. (It is possible that additional carbon is
sequestered in the soil.) In contrast, destroying a hectare of forest releases
200 tonnes of carbon (see "Why Gaia needs rainforests",
Fast-growing reduced-lignin trees will also rot more readily, returning
carbon dioxide more rapidly to the atmosphere, thereby exacerbating global
warming instead of ameliorating it.
Researchers used a NASA thermal infrared multispectral scanner from the
air to assess energy budgets of experimental forests in Oregon in 1989. They
found that a clear-cut forest area had a surface temperature of 51.8C, hotter
than a nearby quarry, which registered 50.7C. The Douglas fir plantation with
mature trees registered 29.9C, compared to 29.4C over the natural Douglas fir
forest regrowth; while the coolest temperature of 24.7C was found over the 400
year-old forest. The cooling effect of the natural forest ecosystem is not only
important for alleviating global warming; it is also a significant indicator of
Insecticidal GM trees destroy biodiversity
There is no doubt that the insecticidal GM trees will kill many insects,
both target pest species and non-target species; that is, until the pests
develop resistance within six or seven years, according to the estimate of Liu
Xiaofeng from Henan Agriculture Department, a scientist critical of the GM
cotton planted in China (see "GM cotton fiascos around the world",
SiS25). At that
point, more insecticides will have to be used, especially as new kinds of pests
will have appeared.
The far greater threat to biodiversity is the spread of the insecticidal
traits to natural forests. Laboratory feeding experiments have shown that Bt
toxins produced in GM crops can harm beneficial predators that feed on insect
pests, even when the pests themselves are not affected by the toxins. One class
of Bt toxins (Cry1A) was found to harm butterflies, lacewings and mice. Another
class (Cry3A) acts against insects belonging to the Order Coleoptera (beetles,
weevils and stylopids), which contains some 28 600 species. Bt toxins are known
to leach out of the roots into the soil, with potentially huge impacts on the
Reduction of insect populations will in turn impact on birds and mammals
that feed on insects.
Herbicide-tolerant GM trees make green deserts
GM trees have been made tolerant to broad-spectrum herbicides that kill
all other plants. If that is not bad enough, they are also harmful to all
species of animal wildlife including human beings (reviewed in
Case for a GM-Free Sustainable World, ISP Report). Plantations of
herbicide-tolerant GM trees are really green deserts, and collateral damage to
nearby forests and crops from spraying herbicides is inevitable, as is the
pollution of drinking water.
Glyphosate is the most frequent cause of complaints and poisoning in
the UK. Disturbances of many body functions have been reported after exposure
at normal use levels. It nearly doubled the risk of late spontaneous abortion,
and children born to users had elevated neurobehavioral defects. Roundup
(Monsantos formulation of glyphosate) caused cell division dysfunction
that may be linked to human cancer. Glyphosate caused retarded development of
the foetal skeleton in laboratory rats. It inhibits the synthesis of steroids
and is genotoxic in mammals, fish and frogs. It is lethal and highly toxic to
Glufosinate ammonium is linked to neurological, respiratory,
gastrointestinal and haematological toxicities and birth defects in humans. It
is toxic to butterflies and a number of beneficial insects, also to the larvae
of clams and oysters, Daphnia, some fresh water fish such as the rainbow trout.
It inhibits beneficial soil bacteria and fungi, especially those that fix
The health hazards of GM trees are common to those of other GM crops,
but they will be exaggerated. Two of these in particular are worth
Agrobacterium, used in the vector system for creating many GM
trees, is a soil bacterium that causes tumours to grow on infected
plants and is now known to be capable of transferring genes into animal and
human cells (See "Common plant vector injects genes into human cells"
Scientists have warned that the Agrobacterium is extremely difficult to
eradicate from the transgenic plants created, and can therefore serve as a
potential vehicle for unintended horizontal gene transfer to soil bacteria and
all other species, including human beings, that come into contact with the
transgenic crops. This danger is greatly increased in GM trees, especially on
account of its extensive root system. The rhizosphere plant root system
- is a known hotspot for horizontal gene transfer.
The potential of Agrobacterium to mediate horizontal gene
transfer, and the resulting hazards of spreading antibiotic resistance marker
gene to pathogens; creating new bacteria and viruses that cause diseases; and
causing cancer in animals including humans were reviewed in Chapter 11 of ISP
Another source of health hazard is the Bt toxins and other transgenes,
which could be spread far and wide in the pollen of GM trees. All Bt toxins
used as transgenes as well as the transgenes conferring glyphosate tolerance
were found to have similarities to known allergens, and are hence suspected
allergens (see "Are transgenic proteins allergenic?" ISIS report 05/01/ 2005