The admission came after warnings about such trees from ministers from over 100 countries at a UN conference in Curitiba, Brazil. They urged a "precautionary approach" towards them after hearing that they could "wreak ecological havoc throughout the world’s forests".
Some 16 countries around the world are developing GM trees, and more than a million have already been planted in China. At least 24 species, from papaya to silver birch, from olive to teak, have already been modified; the most commonly treated are poplar, pine and eucalyptus.
The process can speed growth: GM poplars can grow four times faster than traditional softwood trees used for timber and paper. It has also reduced their content of lignin, which strengthens trees but make the wood harder to pulp and whiten for paper.
Other modifications enable them to produce their own pesticides to fight off insects, to resist diseases and to enable them to endure heavy doses of herbicides so that plantations can be drenched to kill weeds without harming the trees.
A GM orange tree, developed in Sp?in, bears fruit after only one year of life, instead of six. Danish scientists have worked on modified Christmas trees, with a view to developing specimens whose needles do not fall off. And in the boldest suggestion yet, an American professor has suggested that trees could be modified to make the moon habitable by growing "huge greenhouses over their heads".
But the ministers in Brazil were concerned that genes from the modified trees could spread great distances on the wind and across national boundaries. Tree pollen can travel up to 2,000 km. And, because trees can live for centuries, modified examples pose a long-term threat to the world’s forests.
Contamination by genes conferring fast growth, for example, could make some forest trees crowd out other species; genes that produce insecticides could decimate rainforest ecosystems, the richest on earth; and genes that reduce lignin could make trees more vulnerable to pests.
The Department of the Environment, Food and Rural Affairs denied late last week that GM trees had ever been grown in the open in Britain, until given details by The Independent on Sunday.
All the plantations have either been destroyed by protesters or cut down at the end of the experiments. Britain’s only GM trees are now elms, resistant to Dutch elm disease and being grown in "a controlled environment" somewhere in Dundee.
The scientists developing them say they will not plant any outside because they fear "terrorism" by protesters. They will not disclose precisely where they are or give details of the numbers, but confirm that there are "more than a hundred" of them.
Elm
Being grown at a secret indoor location by Abertay University scientists and modified to be resistant to Dutch elm disease. The scientists hope the trees will in time replace the 20 million taken from the British landscape by the disease.
Poplar
Grown at Jealotts Hill Research Station at Bracknell, Berks, and modified so that the wood is whiter for making paper. Most, grown by the biotech firm Zeneca, were destroyed by protesters, but a few were successfully harvested.
Eucalyptus
Grown by Shell Research Ltd at Sittingbourne and West Malling, both in Kent. The tree was modified to resist the use of herbicides, as in most current GM crops. The experiment is now over.
Apple
Greensleeves and Jonagold apple trees, modified to resist insect pests and fungal diseases, were grown by the University of Derby, but destroyed by protesters.
Governments worldwide have issued an unprecedented warning about the greatest biotech hazards so far: GM trees. Trees modified to grow faster, yield better wood, produce whiter paper, resist pests and disease and tolerate herbicides are increasingly being cultivated.
Elms resistant to Dutch elm disease are being grown in Dundee, Scotland. But the scientists involved will not say precisely where they are, or even exactly how many of them are being grown.
The Government was forced to admit for the first time last week that GM poplar, apple and eucalyptus trees have been cultivated outdoors in Berkshire, Derbyshire and Kent.
The admission came after warnings about such trees from ministers from over 100 countries at a UN conference in Curitiba, Brazil. They urged a "precautionary approach" towards them after hearing that they could "wreak ecological havoc throughout the world’s forests".
Some 16 countries around the world are developing GM trees, and more than a million have already been planted in China. At least 24 species, from papaya to silver birch, from olive to teak, have already been modified; the most commonly treated are poplar, pine and eucalyptus.
The process can speed growth: GM poplars can grow four times faster than traditional softwood trees used for timber and paper. It has also reduced their content of lignin, which strengthens trees but make the wood harder to pulp and whiten for paper.
Other modifications enable them to produce their own pesticid?s to fight off insects, to resist diseases and to enable them to endure heavy doses of herbicides so that plantations can be drenched to kill weeds without harming the trees.
A GM orange tree, developed in Spain, bears fruit after only one year of life, instead of six. Danish scientists have worked on modified Christmas trees, with a view to developing specimens whose needles do not fall off. And in the boldest suggestion yet, an American professor has suggested that trees could be modified to make the moon habitable by growing "huge greenhouses over their heads".
But the ministers in Brazil were concerned that genes from the modified trees could spread great distances on the wind and across national boundaries. Tree pollen can travel up to 2,000 km. And, because trees can live for centuries, modified examples pose a long-term threat to the world’s forests.
Contamination by genes conferring fast growth, for example, could make some forest trees crowd out other species; genes that produce insecticides could decimate rainforest ecosystems, the richest on earth; and genes that reduce lignin could make trees more vulnerable to pests.
The Department of the Environment, Food and Rural Affairs denied late last week that GM trees had ever been grown in the open in Britain, until given details by The Independent on Sunday.
All the plantations have either been destroyed by protesters or cut down at the end of the experiments. Britain’s only GM trees are now elms, resistant to Dutch elm disease and being grown in "a controlled environment" somewhere in Dundee.
The scientists developing them say they will not plant any outside because they fear "terrorism" by protesters. They will not disclose precisely where they are or give details of the numbers, but confirm that there are "more than a hundred" of them.
Elm
Being grown at a secret indoor location by Abertay University scientists and modified to be resistant to Dutch elm disease. The scientists hope the trees will in time replace the 20 million taken from the British landscape by the disease.
Poplar
Grown at Jealotts Hill Research Station at Bracknell, Berks, and modified so that the wood is whiter for making paper. Most, grown by the biotech firm Zeneca, were destroyed by protesters, but a few were successfully harvested.
Eucalyptus
Grown by Shell Research Ltd at Sittingbourne and West Malling, both in Kent. The tree was modified to resist the use of herbicides, as in most current GM crops. The experiment is now over.
Apple
Greensleeves and Jonagold apple trees, modified to resist insect pests and fungal diseases, were grown by the University of Derby, but destroyed by protesters.