Act now to save Scottish oak trees from sudden death, experts plead

ACTION must be taken now to prevent a potentially devastating disease that attacks trees and plants sweeping through Scotland, experts have warned.

"Sudden oak death" could kill swathes of trees, and even put Scotland's heather at risk, it is claimed.

The disease, which comes in two forms – Phytophthora ramorum and Phytophthora kernovae – became known as sudden oak death after it killed thousands of oaks in California.

Now groups ranging from the National Trust for Scotland (NTS) to the Society for General Microbiology, have urged the Scottish Government to step up efforts to prevent the spread of the disease here.

It has infected plants in nurseries in Scotland since 2001 but first struck in a public place in October 2007, in Arduaine Garden, Argyll, leading to fears that it could spread through wild areas.

It was discovered in native blaeberry in Merkland Wood, at Brodick Country Park on Arran in November, but has not yet attacked any trees in Scotland, although it has killed many in Cornwall.

More than 20 organisations have responded to a consultation by the Scottish Government, which asked for views on what level of action should be taken to fight sudden oak death.

Most want more research into where the disease has taken hold, as well as the widespread removal of Rhododendron ponticum, which is particularly susceptible, and stricter rules governing nurseries to stop infected plants being spread around the country.

A spokeswoman for NTS said: "Phytophthora ramorum and kernovae are potentially devastating diseases with implications not just for gardens but for wild land throughout Scotland and the UK. The charity has been concerned by the way the diseases have spread through 2008, particularly with the discovery of infected blaeberry on Arran.

"Co-ordinated and consistent action led by the government in 2009 to improve our knowledge and understanding of these diseases could help stop the spread in the long term."

Dr Deborah Long, conservation manager for Plantlife Scotland, thinks the future impact of the diseases on Scotland's native plants in woodlands and heathlands is "potentially devastating and could lead to severe degradation of key habitats of international importance".

Trees grown in commercial forests in Scotland have been shown to be at risk, including sitka spruce, Scots pine and douglas fir.

Jamie Farquhar, national manager for Scotland at the Confederation of Forest Industries is worried about the potential impact if it takes hold in woodland to a similar extent as it has in the south of England.

"If a similar situation were to develop in Scotland, our losses, given the relatively greater importance of our forest industry to the north could be immense," he said.

And the Society for General Microbiology warns in its response that it may already be too late to stop the spread of Phytophthora ramorum – the more common of the two diseases.

The scientists thought there was far more hope of eradicating kernoviae, and gave the advice: "Act before it is too late."

Michael Russell, environment minister, said: "We have received an encouraging number of responses to the consultation and are considering them."


Fungus could devastate native species

What is Sudden Oak Death?

The name given to a fungal disease called Phytophthora ramorum, discovered in 1993, which killed oak trees in California and has since attacked numerous other species. A related disease, called Phytophthora kernoviae, was discovered in Cornwall in 2004.

Which plants are susceptible?

Ramorum can affect rhododendrons, bilberry, viburnums, witch-hazel, lilac, yew, oaks, beech, sweet chestnut, Sitka spruce and Douglas fir. Kernoviae has been found on rhododendron and beech trees and others including magnolia.

How does it spread?

It is believed the fungus could be spread by rain splash, wind-driven rain, on the soles of shoes and by animals.

What are the symptoms?

Ramorum causes large cankers on the bark of trees, which appear to bleed a red sap. On rhododendron, it turns shoots black and leaves drop off.

How widespread is the disease?

It was first spotted in Germany and the Netherlands, but it has since been found in Belgium, Finland, Denmark, France, Ireland, Italy, Norway, Poland and Spain.

Why does it pose such a risk to Scotland?

It is feared native species, including heather, could be at risk.