SCOTLAND'S newly created national tree, the Scots Pine, is under siege from the threats of climate change, severe weather, over-grazing and disease, according to conservationists.

The charity Trees for Life is warning that higher priority must be given urgently to the conservation of Scotland's pinewoods.

Executive director Alan Watson Featherstone said this winter's severe storms had highlighted the vulnerability of even well-established Scots Pines to extreme weather, something that was likely to increase with climate change. There was also a lack of young trees to replace mature specimens when lost.

He said that while declaring the Scots Pine as a national symbol sent a signal to the world that Scotland valued its trees as an important part of its culture and identity, alarm bells were ringing for its future.

"We owe it to future generations to ensure its long-term survival by being world leaders in reforestation," he said.

During the powerful storm that struck north Scotland in early December, several giant Scots Pines at Trees for Life's Dundreggan Conservation Estate near Loch Ness were uprooted and blown over, and others badly damaged, he said.

Some of these were probably more than 200 years old. Ancient pines were also lost in the Glen Affric National Nature Reserve.

Trees for Life said that while others would grow, it would be at least 200 years before they would be comparable to those lost.It added: "In a healthy forest ecosystem, deer numbers would be in balance with regenerating trees but imbalances in the Highlands landscape have created a 200-year generation gap for Scots pines. Until fencing and conservation-oriented deer culling began in the past two decades, there were no trees younger than 150 years in most locations."

Another potential threat is Dothistroma Needle Blight, which normally affects Lodgepole and Corsican Pine in Scotland. The Scots Pine was believed to have low susceptibility to the disease. However the Forestry Commission had noted an increase in the distribution and severity of the disease on Scots Pine, particularly in Scotland.