UK's ancient forests could spread again thanks to plan to clone 'super-trees'
Some of Britain's best-loved trees could be cloned in an effort to reproduce a range of our most successful and sturdy oaks, yews and firs.
The £2m scheme to reproduce and grow again all of Britain's biggest, oldest, tallest and most ecologically important trees has been devised by the US tree conservationist David Milarch, who hopes to reproduce all the UK's "super-trees" and then offer tens of thousands of their genetically identical offspring free to schools, cities and landowners. Famous trees that could be cloned include the Major Oak in Sherwood Forest where Robin Hood is said to have sheltered, a 3,000-year-old yew in Berkshire and a majestic 209ft fir in the Scottish Highlands.
"We are looking for the oldest and largest oaks, limes, yews, some species of maples and other trees," said Milarch. "The idea is to put back what we have lost. It makes sense to use the largest, oldest, most iconic trees with their supergenes. These trees, which can be 1,000 years or older, have weathered the industrial age and all the climate changes. They have proved that they can take everything. When you clone, you get 100% identical genetics, the whole lineage."
Milarch, who is backed by the Eden project founder Sir Tim Smit and SirRichard Branson, is in Britain this week for talks with specialists on ancient trees and Prince Charles's forestry experts. He expects to draw up a list of Britain's "super-trees" in the next few weeks and start cloning this summer. Eventually he hopes to establish a complete archive of all Britain's most important trees, which would be made publicly available.
The practice of producing genetically identical copies of trees is not new. Typically, the tips of branches are cut, dipped into a rooting hormone and then fed and kept warm. The stem cuttings go on to form roots and the new plant is genetically identical to the plant that the cutting came from. But, in practice, it has proved nearly impossible to clone some of the world's botanical behemoths. "It can take 1,000 pieces of plant to get two or three to root," said Milarch, head of a fourth-generation tree nursery group in Michigan. "It might take 5,000 pieces. We needed 15,000 attempts to get three clones from one redwood. All we need is one to root, one to grow, one to take off.
"Everyone has said that you cannot clone old oaks. But we now have all 22 of the great oaks of Ireland cloned. No one had ever been able to clone with 1,000-year-old trees, but we can now do it. We could produce millions of [any one] tree in a year." So far, Milarch and his conservation organisation Archangel have successfully cloned 75 species, including redwoods, giant sequoias, Monterey cypresses and the Monterey pine. They have also cloned theMethuselah bristlecone pine, thought to be the oldest tree in the world at 4,845 years old.
Last year he successfully cloned the Fieldbrook Stump, the remains of the largest coastal redwood that has ever lived with a diameter of 9.8m (32ft) which may have soared to more than 40 storeys high before it was felled 130 years ago. Only a small number of tree species have the genetic capacity to grow to a great size, but little is known about why some trees live far longer than others, or how much their growth is determined by the broader environment in which they grow.
But scientists are learning that the "super-trees" are vital for the health of entire forests because they seed large areas and may contain as much as 25% of the total biomass. William Laurance, a research professor at James Cook University in Cairns, Australia, said: "Long-term studies in Amazonia, Africa and Central America show that, while these great old trees may have adapted successfully to centuries of storms, pests and short-term climatic extremes, they are counter-intuitively more vulnerable than other trees to today's threats. "They may comprise less than 2% of the trees in any forest but are ecologically vital. They are dying off rapidly as roads, farms and settlements fragment forests and they come under prolonged attack from severe droughts and new pests and diseases."
Milarch is working in New Zealand to re-establish giant kauri trees, and in Africa where he has been commissioned to recreate a forest of all the continent's greatest trees. "We welcome this UK initiative. Cloning has the big advantage that you get the original tree. If you clone an 800-year-old tree it may be only 10 trees away from the ice age. They have been through significant changes of climate," said Jill Butler, the Woodland Trust's adviser on ancient trees.
