An urgent survey of Scottish woodland will get under way this weekend to assess the extent of the fungal disease threatening to wipe out the UK's ash trees.

Forestry Commission Scotland is drafting in 100 members of staff over the next four days to map out the spread of the infection, known as ash dieback, which has so far led to 100,000 British trees being destroyed.

The moves comes after UK Government Environment Secretary Owen Paterson convened an meeting of emergency committee Cobra including ministers, experts and officials, including representatives from Scotland.

After the meeting, he said a mass survey of trees in almost 3000 test areas should produce a clear picture of the extent of the threat by the middle of next week.

A spokesman for Forestry Commission Scotland said: "The Cobra meeting signifies how seriously Scottish and UK ministers are treating the situation. Forestry Commission Scotland has already acted swiftly to combat this very serious disease – we're doing all we can to try and cut it off in its tracks.

"We very quickly cleared the one infected planting site in Scotland, have suspended ash planting on Commission-managed sites and have worked with the forestry industry to put everyone on high alert. Over the next four days we will also have over 100 staff surveying ash woodlands throughout Scotland to determine the extent of the disease and the next phase of our response."

The fungal disease has killed up to 90% of ash trees in some areas of Denmark and has now been found in Britain – with one expert warning it could wipe out 19 of every 20 ash trees.

It has been reported at four newly-planted Scottish woodlands.

Saplings have been uprooted and burned at Knockmountain Wood, near Kilmacolm, Inverclyde and at a nursery at Fochabers in Moray.

The disease is suspected at sites at Carrbridge, south of Inverness, and a fourth unidentified location in the south-east of Scotland.

The UK Government banned imports of ash trees on Monday, but the discovery of the disease in mature trees in East Anglia has raised fears it has blown in to the UK as well as arriving via imports, and will be hard to control.

Yesterday it emerged that another potentially infected site had been found in Kent.

Professor Ian Boyd, chief scientific adviser for the Department for Environment, Food and Rural Affairs (Defra), said he expected more trees to become infected in coastal areas.

"We have known that there's a possibility of infection but we have to confirm that – it's not confirmed at the moment.

"I think the general message is that we now are seeing a pattern which is suggesting there's been transmission by wind across from the Continent, so we probably should expect some forms of infection to emerge along coastal regions."

Experts are concerned the ash could face the same fate as the elm, which was devastated by Dutch elm disease in the 1970s.

Ash dieback could have a dramatic impact on wildlife, and lead to rare species being lost if it takes hold.

Professor Michael Shaw, a plant disease expert from the University of Reading, said the disease could be "catastrophic" for ash trees.

He said: "It's a very familiar tree, it's important to the landscape and to lose it would be catastrophic. That looks as though that may be what will happen.

"If the epidemic becomes established . . . it will have knock-on effects on the insects that feed.

"In an urban or garden setting, it would be disastrous for individuals."