Ashes to ashes: woodlands in fight for survival

By JULIA HORTON
Published on 19/11/2012 00:00

IN THE middle of a Scottish forest, row upon row of saplings in stark white protective cases stand like cemetery markers in the thick, black earth.

The young trees are among the victims of the deadly chalara ash dieback disease which has spread across Scotland and the rest of the UK.

Right now nothing more can be done to save them – the plastic casing is just a routine, unrelated measure to prevent deer eating the tender shoots.

But the shields hide the telltale scarring and lesions found on some of the trees here believed to have been caused by the fungal infection which experts fear could be as devastating as Dutch elm disease.

Town Wood outside Dalbeattie in Dumfries and Galloway is one of 14 sites across Scotland where signs suggesting infection were found in an emergency nationwide survey conducted earlier this month by the Forestry Commission Scotland (FCS).

Experts are analysing samples to confirm the infection and help find ways of minimising the damage to woodlands.

No-one yet knows how many of the 7,000 saplings at Town Wood lost their leaves as a result of disease rather than seasonal change.

Removing one of the plastic tubes, Bill Coombes, environment and community manager for the FCS Dumfries and Borders district, said: “This is a very clear example of an open wound at a leaf join [where a stalk meets the main stem of the sapling].

“It’s like a wound which has burst open.”

The lesion looks exactly like the textbook image on a disease checklist he is holding.

Another sign of the disease is leaf discolouration and loss, which is similar in appearance to the harmless effects of
autumn – making it harder to confirm signs of dieback at this time of year.

As the infection lies dormant during the winter, the extent of the outbreak will not be known until late spring next year when conditions are warmer.

For that reason there are no warning signs urging the dozens of dog walkers and joggers
who visit this popular woodland to clean their footwear when leaving to minimise the risk of spreading the disease
further.

However, general advice from the FCS encourages the public and forestry staff to take such
action as a precaution.

The disease affecting ash – the third most common broadleaf tree in the UK – has been found in both saplings and mature trees, suggesting that it has been spread via windblown spores and also as a result of planting imported trees which were infected.

A strategy for controlling the disease, drawn up following a summit in Scotland earlier this week, includes identifying potential safe zones where ash can be protected from the fungus.

Sites are likely to be in the north and west of the country, in isolated areas away from contact with imported plants and in sheltered areas far from mainland Europe, where the disease has wiped out most of Denmark’s ash trees.

The UK government introduced a ban on imports last month.

Refuge zones are also being identified for threatened trees in a bid to help save Scotland’s woodlands from the spread of the disease.

Experts are looking for locations in the west and north-west which are naturally protected from the wind – which can carry the spores of the dieback fungus – and also isolated from contact with infected, imported saplings.