Tropical forest, Vella Lavella, Soloman Islands.
Trees, which have long life cycles and grow in intricate
ecosystems, are in the earliest stages of domestication. Planting
genetically engineered (GE) trees poses potentially devastating
environmental risks. Greenpeace is calling for an immediate ban on
the release of GE trees into the environment, because of the threat
of irreversible genetic pollution.
Scientists say that physical confinement of pollen, and in some
cases even the seeds, from forest trees is for all purposes
impossible. Aware of the problems of gene escape, the Biotech
industry often claims that engineering tree sterility is a
solution. But engineering persistent sterility could prove very
difficult, and in fact such research constitutes only a tiny
fraction of GE tree research. Furthermore, GE-sterile trees could
revert to fertility in the future as a reaction to external
stressors and pass genes for sterility onto wild populations.
The introduction of foreign genes into any organism can cause
unintended side effects for ecosystems. For example, scientists are
studying how to reduce lignin content in trees. Lignin is a
material that adds strength and rigidity to plants, but makes it
harder to pulp wood for paper. But reduced lignin could speed up
the decomposition of trees, altering soil ecology, structure and
fertility.
Genetically engineering can also produce unwanted and unexpected
side effects, many of which will be hard to detect in GE trees, due
to their long life spans. It may take several years for undesired
traits, or instabilities in the desired traits, to express
themselves.
One sought-after outcome of GE tree research is species that
grow faster. Such trees might quickly deplete soils through
unusually rapid uptake of nutrients. In addition, fast-growing
super trees might put increased pressure on water supplies, a
scarce resource in many regions. Moreover, if the fast-growth trait
were transferred to wild relatives, these plants could quickly
become pests, with serious ecological consequences.
Researchers are also engineering trees to become resistant to
herbicides (weed-killers). Such GE trees could result in increased
aerial spraying of weed-killers, which would considerably increase
the risks of chemicals entering water-ways and damaging ecosystems.
Furthermore, herbicide- or insect-resistant trees could transfer
their extra "resistance genes" to wild relatives. These plants
could become "super weeds".
Thus far, no applications for unrestricted, commercial use of GE
trees have been filed. However, experimental releases with GE trees
have been approved in several countries including the USA, UK and
South Africa with more than 200 field trials in the US alone.
For more information download the Greenpeace report -
Pulp Fiction, Genetically Engineered trees.