How ancient roots give forests a better chance of survival

Published on Wednesday 8 September 2010 13:46

Pine trees in the Scottish Highlands are direct descendants of the Caledonian forests that colonised the area immediately after the Ice Age, scientists have discovered.

Researchers from Edinburgh's Centre for Ecology & Hydrology previously believed that any genes of the original trees had disappeared - leaving the existing woodlands less equipped to adapt and survive under changing climatic conditions, such as global warming.

But they have now identified gene types linking back to Scots pine trees that existed thousands of years ago.

"These trees are actually direct descendents of the colonisers which originally came to Scotland after the Ice Age," said Dr Stephen Cavers, the ecologist leading the research.

Dr Cavers said the discovery could help regenerate future populations of trees in the area.

"It could help a lot in replanting initiatives," said Dr Cavers, who carried out the research with scientists from the University of Edinburgh, the Macaulay Land Use Research Institute and the Polish Academy of Sciences. "If you could say that you're using local materials and trees that could adapt best, that would be of great benefit in the future. Diverse genetics means the population is likely to be a lot stronger and a lot more resilient than if there was a lot of inbreeding in the population."

It is believed that the original trees of the Caledonian forests that covered the north of Scotland grew in the years following the last Ice Age, when pollen drifted over from existing species of pine trees in central Europe and Spain.

"These trees have now spent a long time in Scotland and have adapted to conditions here," said Dr Cavers. "It was quite surprising.We were expecting that on the edge of the range, especially, there would be a lot fewer of these trees."

Most species descended from the original trees were wiped out more than 400 years ago by over-exploitation of the forests and agricultural activity.

Scientists believe that as Scots pine trees can live as long as 700 years, the forests present today may be no more than a few tens of generations removed from the first migrants to reach Scotland after the ice melted 9,000 years ago.

A spokesman for the RSPB Scotland, which owns and manages the largest remaining expanse of original Caledonian forest at its Abernethy reserve, said: "Of the vast ancient Caledonian pine forest that used to cover so much of Scotland, only 1 per cent now remains.

"As well as conserving this uniquely precious habitat and all the species it hosts, we are actively trying to expand and restore it, extending it across the reserve to create a continuous, self-sustaining native forest over the whole potential area.

"It is critical that we have the best seed stock with a strong genetic variation to allow this to happen, so this research is very welcome news."