Deadly oak disease hits Welsh private woodland


An outbreak of the pathogen Phytophthora ramorum, otherwise known as sudden oak death, has been discovered for the first time in Wales on trees in a privately-owned woodland, reports the Forestry Commission Wales.

Staff from Forestry Commission Wales and the Food & Environment Research Agency (Fera) have visited the owner of the woodland in Denbighshire and a notice has been served to fell the infected Japanese larch trees. Only a small number of trees are infected, and the owner will use the timber on site.

Sudden oak death is a fungus pathogen that kills many of the trees that it infects. It was first found on Japanese larch trees in Wales in June this year in public woodlands  near Port Talbot, near Bridgend.

The outbreak in South Wales was the first time P. ramorum has been encountered on larch elsewhere in Great Britain since it was first discovered on larch in South-West England in 2009.

The woodland owner, Wendy Charles-Warner, contacted Take Cover, to say: “We feel rather aggrieved at the tone of the [Forestry Commission] press releases stating that we have been served with enforcement notices as if we were responsible for this outbreak and somehow in the wrong.

“We could take no steps to prevent this disease which is mainly airborne, have done nothing wrong and have at every point done everything we can to assist the forestry commission.”

A motor rally set to attract thousands of spectators to South Wales in July was postponed as a result of an ou6tbreak of the tree disease.

The route of the Swansea Bay Rally ran through forests that had been hit by the infection.

Richard Siddons from the Forestry Commission Wales said the organisation was “determined to minimise the impacts of this serious tree disease on woodlands, and the support of woodland owners in looking out for early signs of P. ramorum infection will play a key part in achieving that”.

It seems as if the warm but wet summer has been a key driver in the development of tree pathogens, with a number of cases making the headlines.

In April, a group of woodland experts expressed their fears for the future of British native oaks in light of the emergence of a disease called Acute Oak Decline, a bacterial infection that, they warned, could be as devastating for the English Landscape as Dutch elm disease in the 1970s.

They called for much more financial support from the UK government to help tackle the problem through research and land management measures.

In July, the Forestry Commission announced a £600,000 support package for woodland owners in South-West England and Wales to help tackle the outbreak of P. ramorum infection on larch trees. The package is part of Defra’s £25 million, five-year Phytophthora management programme.

Forestry Commission Wales is developing a complementary programme of support for private woodland owners who have P. ramorum confirmed on their land. Details of this support will be announced in September.

Ms Charles-Warner, in her comment to the story on this blog (see below for her full response), added: ”

The ‘package of assistance’ that the Commission have announced is £300 per hectare, which we are not receiving or going to receive.

“If you have knowledge of tree felling you will appreciate that in a situation where stringent biosecurity measures have to be used and the trees have to be felled and brashed by hand that is a paltry sum, even in the highly unlikely event that you receive it.

She went on to say that she was “deeply concerned” about the situation: “If the Commission wishes landowners to report Phytopthora Ramorum and control it, in order to protect commercial forestry, then realistic support needs to be in place.

“Many landowners faced with a the prospect of funding felling and site clearance work themselves with the attendant stress and unpleasantness, are likely to ignore the disease and not report it.”

More information about sudden oak death can be found on the Forestry Commission’s website at www.forestry.gov.uk/pramorum.

To find out more about the support fund or to report suspected P. ramorum infection in their trees, woodland owners should contact Forestry Commission Wales’s Grants & Regulations Office on tel: 0300 068 0300 or email: bww.ts@forestry.gsi.gov.uk.

Source: Forestry Commission Wales press release

Date: 25/08/2010

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Oak disease ‘threatens British landscape’


The continuing spread of a deadly disease that affects the UK’s native oak trees is causing concern among tree professionals and conservation groups.

Take Cover library photoThe BBC’s environment reporter Mark Kinver writes that Acute Oak Decline (AOD), caused by a bacterial infection, can kill an infected tree in just a few years.

Some tree experts are comparing AOD to Dutch elm disease, which killed millions of trees throughout the UK during the 1970-80s.

They said extra funds for more research into the disease were urgently needed.

Although AOD has been confirmed in 55 cases, the number of trees displaying symptoms was steadily increasing, delegates at the Royal Forestry Society’s (RFS) annual conference were told.

The disease affects the UK’s two native species of oak – sessile and pedunculate. To date, there have been no confirmed cases in other species of oaks found in Britain, such as Turkey and red oaks.

‘Extensive bleeding’

Information from Forest Research, the scientific department of the UK Forestry Commission, says the new disease affects oaks more than 50 years old.

Symptoms are “extensive stem bleeding” in which dark fluid seeps from small cracks in the bark and runs down the tree trunk.

In early stages of the disease, the health of a tree’s canopy does not appear to be affected, but it may become thinner as the tree succumbs to AOD.

On its website, Forest Research says: “The incidence of AOD in Britain is unquantified at this stage, but estimates put the figure at a few thousand affected trees.

“The condition appears to be most prevalent in the Midlands and investigations to determine the extent of the disorder are under way.”

A spokesman told BBC News: “Forest Research pathologists have isolated a previously unidentified bacterium they believe is highly likely to be playing a key role in the Acute Oak Decline observed in Leicestershire and elsewhere.

“However, the full cause of the condition is thought likely to be complex, involving a number of factors besides the bacterium. A research report is currently awaiting peer review.”

‘Major threat’

Tree organisations are calling for more funding to be made available to allow researchers to better understand the full impact of the disease.

John Jackson, the organiser of the RFS’s conference, said: “Urgent action is not an option – it’s a necessity.”

Hilary Allison, policy director for the Woodland Trust, added: “The impact of the loss of an iconic tree both from our countryside and towns would be catastrophic, and therefore has the capacity to be a major threat to the UK’s oak woods.”

“I have never seen anything like it,” said Peter Goodwin, co-founder of Woodland Heritage.

“Its spread over the last two years has been quite alarming.”

Mr Goodwin told BBC News that very little was known about the virulent bacteria responsible for the disease.

“We’ve never had a bacterium that is capable of doing what this one is doing.”

He suggested that people were possibly the main way in which the disease was spread from tree to tree, but added that “natural vectors” – such as squirrels, birds and insects – could also play a role.

“I think this is the worrying thing, we all want to know what are the vectors that is spreading it. Is it airborne? We just don’t know.”

Forest Research advises people working in affected areas to take appropriate measures to limit the chances of AOD being carried to new sites.

“The most important thing we can do in this and other cases is to research and understand the causes so that we can provide appropriate management advice for tree owners and woodland managers,” the spokesman added.

“It is also important that we remain vigilant against accidentally importing new and damaging pests and diseases from outside Great Britain.”

Source: BBC News website

Date: 28/04/10

Plant diseases threaten woodlands


Some of the finest gardens and woodlands in Britain are under threat from two closely related and aggressive fungus-like plant diseases, the BBC News website reports.

UK Environment Minister Jane Kennedy said they were attacking “pristine” locations and could potentially damage the landscape and the tourism industry.

The government has allocated £25m in a bid to eradicate the diseases which are spreading across the country.

They are Phytophthora kernoviae and Phytophthora ramorum .

Rhododendrons, a carrier of both diseases, are likely to be removed in woodland in order to curb the spread of the pathogens.

The flowering shrubs, popular as an ornamental species in many gardens, also grow wild in wooded areas and an area of the New Forest has already been cordoned off to allow rhododendrons to be cut down and burned.

Phytophthora kernoviae , first found in the south-west of England in 2003, reached Scotland five years later.

It attacks and kills many trees and shrubs, including the oak and beech trees which make up so much of Britain’s woodlands.

The Department of Environment, Food and Rural Affairs (Defra) says 69 sites in England and Wales are currently affected, with Cornwall the worst-hit region.

Phytophthora ramorum , first identified in 1995, has devastated woodland on the west coast of the United States where it has been responsible for the syndrome known as “sudden oak death”.

Few control mechanisms exist for the disease, so the importance of early detection – and proper disposal of the infected plant material – is key.

The government is to earmark some of the money for new research and development, and there will be a campaign to make landowners aware of the threat.

Source: BBC News website

Date: 03/03/2009

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