Rise from the ashes

Experts have accepted it is probably too late to eradicate the Chalara fraxinea fungus and have warned against a policy of “slash and burn”, as that may result in ash trees that are resistant to the disease being felled.

Dr Tony Whitbread, of the Sussex Wildlife Trust, says, “The disease is now here and we’re going to have to live with it.”

Ash dieback first appeared in Britain last November, probably as a result of spores borne on the wind from the continent, and from imports. The first cases in Britain were spotted in Kent and Essex, which have coastlines facing Europe, and later in East Anglia and Sussex.

The government’s Department For Environment, Food And Rural Afairs (Defra) implemented a plan of action to reduce the rate of the disease’s spread, develop resistance in the country’s native ash trees and encourage the public to help tackle the problems.

Diseased trees

It ordered the destruction of newly planted diseased trees and those in nurseries, but agreed that mature trees would not be removed, and that research and surveys would help identify genetic strains resistant to the disease.

It also pledged to search for the disease in towns and cities as well as the countryside, and to inform the public, foresters, land managers and environment groups on how to identify diseased trees and what to do about them.

Environment Secretary Owen Paterson says: “The scientific advice is that it won’t be possible to eradicate this disease now that we have discovered it in mature trees in Great Britain.

“However, that does not necessarily mean the end of the British ash. If we can slow its spread and minimise its impact, we will gain time to find those trees with genetic resistance to the disease and restructure our woodlands to make them more resilient.”

Tree experts have estimated that 95% of Britain’s 80 million or so ash trees are under threat, and here in Sussex, the most wooded county in the UK, ash trees form a large part of the mixed Weald and Downs landscapes.

Ash dieback is set to be the third devastating blow to the county’s trees over the past half century. In the 1960s Dutch elm disease appeared in Britain, decimating the country’s 25million elm trees and leaving few of the county’s elms still standing, except in Brighton and Hove, where isolation and efforts by local authorities ensured the survival of 15,000 elms, some of which are more than 400 years old.

Vulnerable

And 25 years ago, Sussex took the brunt of the Great Storm of 1987, when wind speeds of up to 110mph downed thousands of trees across the county, including historic trees at Wakehurst Place in Ardingly and Nymans Gardens near Haywards Heath.

The high proportion of trees in Sussex makes it particularly vulnerable to the spread of tree diseases, and with ash trees prominent in many of the county’s woods and forests, the threat of ash dieback looming on the horizon look set to once again change the face of Sussex’s countryside.

“Ash dieback has been reported to kill 90% of trees in some areas,” warns Dr Whitbread. “However, ash trees are one of the most freely regenerating of the trees we have. Leave any area of ground near an ash tree alone and pretty soon you’ll have thousands of small ash seedlings competing for space.

The most successful will survive but the vast majority will die.

Friston Forest

“So, in freely regenerating areas, 99% of these small ash seedlings could easily be lost and there will still be more than enough potential new trees available. This will be far more vigorous, more successful and more genetically varied than a few replacement planted trees.”

Dr Whitbread also points out that tree diseases happen naturally, causing woodland trees to die. “In limited amounts, it’s a natural process that opens up woodlands, allowing light to reach the floor and encouraging natural regeneration to flourish,” he says. “This is not damage, this is nature. The effect is to make a woodland richer.”

Across Sussex, woodlands have remained open to the public, although visitors are advised to wash their footwear and their dogs to avoid spreading the disease.

Local authorities in the county are issuing advice and guidance, asking members of the public to report any cases of the disease, which mimics autumn dieback and causes leaf loss and crown dieback.

Vigilence

With two reports of ash dieback in East Sussex, including one in woodland between Horsham and Haywards Heath, Horsham District Council has asked residents to “remain vigilant”, although there are no cases within the borough of Horsham itself.

Other authorities are also taking precautionary measures. Hastings Borough Council, for example, has drawn up an action plan to contain the spread of the disease among woodland in Hastings and St Leonards, which has a particularly high proportion of native woodlands, wooded parks and trees with ash a prominent tree species in the borough.

“Reported sightings by the general public, as well as from the Forestry Commission and Defra, are so important,” says Dr Whitbread. “It tells us how widespread the disease is and what management strategies might work.

“Any strategy must be led by science. Cutting and burning suspect trees over a large area would not prevent the disease spreading, but it would stop the development of any resistant ash population and it would damage the woodland ecosystem.”

For more on spotting ash dieback and reporting it, visit www.forestry.gov.uk/chalara.

For more information about Sussex Wildlife Trust, visit www.sussexwildlifetrust.org.uk.