Despite the severe warnings from scientists of the threat to wildlife, biodiversity and ecosystems, Canada continues to permit field tests of trans genetic forest trees. The fear is that these tests are just a prelude to the commercialization of GE trees, which could be catastrophic for the environment.
So far transgenic forest trees have only been marketed in China, but over 250 experimental releases of GE forest trees have been conducted worldwide. Canada has been field testing GE trees since 1997. The research is driven primarily by private business from developed nations, including some of the world’s largest pulp and paper companies.
Greenpeace is calling for a ban on the release of transgenic trees and, as an interim measure, recommends a global moratorium on commercial and large scale experimental releases. In a submission to the scientific body of the Convention on Biological Diversity, Greenpeace provides evidence of the significant ecological risks associated with transgenic forest trees, which are likely to prove unmanageable and irreversible.
One of the biggest threats is that GE forest trees will take over natural landscapes, irreversibly usurping the native vegetation upon which a whole array of other plants and animals depend. Although they are largely intended to be grown on plantations, it is naïve (and irresponsible) to think GE trees will be confined there. Trees typically produce a very large number of seeds, and while most of these seeds are usually deposited in close vicinity, smaller amounts can spread across very large distances. Wind and water also can carry seeds and pollen from trees across great distances, while birds, bats, and small animals help trees to conquer distant habitats. In this way, conifer seeds can travel dozens of kilometres and the seeds from pine trees - one of the most widespread and invasive species as well as one of the species subject to GE research - can be carried up to 30 kilometres by the wind. In particular, trees that have been intentionally or even unintentionally altered with genes to improve their fitness could become more invasive, taking over new habitat and destroying biodiversity and disrupting ecosystems.
The corporate counter to this problem of uncontrollable propagation poses an even bigger risk. GE terminator trees, designed to be sterile would mean no birds, no insects and no mammals that rely on those seeds, pollen and nectar for food. The impact on forest biodiversity would be catastrophic.
Trees also propagate from shoots, and because they breed relatively easily with related species, they would inevitably pass on their genes to wild relatives and transfer their transgenes to micro-organisms.
A number of varieties of transgenic forest trees have been developed to resist insects, including two species of poplar which have been commercialized in China. Although there are no studies of their potential effects on non-target organisms, the fact that they can be affected is apparent from experiences with annual crop plants. Similar effects have also been observed in the soil. GE crops can affect the bacteria, earthworms and soil respiration. Compared to annual crop plants, insect resistant trees offer scope for even more frightening scenarios. The leaves of GE trees planted along a river or the shore of a lake could easily enter the waterways with unforeseeable consequences for the aquatic life.
