September sale of timber from infected Japanese larch

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31 AUGUST 2011NEWS RELEASE No: 14906

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September will see a significant quantity of timber coming to the market from Japanese larch trees felled by Forestry Commission Wales due to the outbreak of ramorum disease.

The timber will be sold via Forestry Commission Wales’s online E-sales system on Wednesday 7 September and in further sales in November 2011 and January 2012.

Ramorum disease is caused by the pathogen Phytophthora ramorum (P. ramorum).  The only known way to prevent its spread is to fell infected trees in order to kill the living plant material on which the pathogen depends. 

Although ramorum disease is fatal to Japanese larch trees, it does not harm the timber and biosecurity measures have been put in place to allow logs from infected trees to be taken to sawmills without spreading the pathogen to other trees or plants.

Craig Sinclair, Production Manager from Forestry Commission Wales’s Harvesting and Marketing team, said, "Speed is of the essence when felling infected Japanese larch trees as, in the autumn, they produce huge quantities of the spores that spread ramorum disease.

“In order to manage this outbreak, we are felling many more Japanese larch trees in South Wales than normal.

“However, we have adjusted the overall volume of these trees harvested in Wales so that we can meet our annual production target of 770,000 cubic metres of timber, which is set at a level we can sustain in the longer term.”

Last year, 876 hectares of Japanese larch trees were found to be infected by ramorum disease in Wales for the first time.

Initial findings from this year’s surveys of woodlands by Forestry Commission Wales indicate that this fatal tree disease has infected a further 227 hectares of larch trees in Wales.  Most of the newly diagnosed trees are in woodlands adjacent to the areas found to be infected with ramorum disease last year in the Afan Valley, near Port Talbot.

"The worst case scenario would have been to have found the same number, or even more, trees infected by ramorum disease this year as last year, but, so fortunately, this does not seem to be the case, ” said Craig.

"Whilst it is worrying that we have to fell a large number of infected trees again this year, it would seem that our decision to swiftly fell infected trees last year has played a key role so far in managing this major outbreak.

"We are determined to minimise the impact of ramorum disease on woodlands and the forest industry and we are grateful for the co-operation and flexibility the industry has shown.”

Further information about Phytophthora ramorum is on the Forestry Commission’s website at


1. Ramorum disease of larch is caused by the pathogen Phytophthora ramorum (P. ramorum), which can infect more than 150 species of plants and trees.

2. P. ramorum was first identified in the United Kingdom in a viburnum plant in a garden centre in West Sussex in 2002. It has since been found infecting a wide range of plants and trees throughout the UK. Until recently it had mostly affected shrubs such as rhododendron, camellia and viburnum, but only a limited number of trees; and from late 2008 infection has been found in the environmentally important bilberry plant (Vaccinium myrtillus - known as blaeberry in Scotland and winberry in Wales).

3. In August 2009 P. ramorum infection was confirmed in Japanese larch trees in South West England. This was the first time it had been found infecting a commercially important conifer tree species anywhere in the world, and has since been confirmed in larch trees in all four countries of the UK as well as the Republic of Ireland.

4. Tree mortality is rapid – P. ramorum appears to be able to kill Japanese larch trees within one growing season after its presence is first detectable, which, compared with other tree diseases, is fast acting. In Japanese larch, it causes shoot tips to wilt and needles to turn black and fall prematurely. Cankers that bleed resin can appear on the branches and upper trunk.

5. Infected Japanese larch trees produce particularly high numbers of the spores that spread the disease – much higher than the level produced on Rhododendron ponticum. This means the disease can quickly affect a large number of trees and shrubs. The pathogen can be spread in mists, rain and air currents.

6. P. ramorum is a ‘quarantine’ organism under European Union law, and its presence on trees or woodland plants must be notified to the relevant authorities (Forestry Commission, Fera, Welsh Government or Scottish Government), who must take statutory action to contain or eradicate it.

7. Forest Research scientists have advised that the most effective means of preventing the spread of the disease is to fell infected trees and plants to kill the living plant material on which the pathogen depends.

8. P. ramorum does not harm the timber, and logs from infected trees can be sold into the timber market, subject to biosecurity measures to ensure that their movement does not further spread the disease.

9. Larch is a durable, versatile timber that tolerates changes between wet and dry conditions very well, resists rotting when used in the ground, and is easily stained, worked and finished. It is therefore in demand for outdoor uses as well as flooring and chipboard.

10. There are about 134,000 hectares (331,000 acres) of larch woodland in Britain: about 5 per cent of the total woodland area.

11. P. ramorum is not harmful to humans or animals, and all public woodlands remain open to visitors, except in areas where felling operations are taking place, which are temporarily closed for safety reasons.

12. P. ramorum causes the disease known as "sudden oak death" in the USA, where a different mating type has killed millions of North American native oak and tanoak trees in California and Oregon. However, its American common name is a misnomer in Britain, where laboratory tests have shown that our native sessile and pedunculate oaks are much more resistant to P. ramorum than their American cousins, and fewer than five native oak trees have been confirmed with P. ramorum infection in Britain. Therefore the generic term ‘ramorum disease’ is used in Britain instead of ‘sudden oak death’.

13. P. ramorum should not be confused with acute oak decline (AOD), which is a separate disease affecting oak trees in the Midlands and parts of Wales and South East England, and in which a newly discovered bacterium species appears to be involved.

Media enquiries

• P. ramorum in Great Britain overall and P. ramorum research - Charlton Clark, 0131 314 6500;

• P. ramorum in Wales - Mary Galliers, 0300 068 0300;

• P. ramorum in England – Stuart Burgess, 0117 372 1073 or Becci Turner 0117 9066030;

• P. ramorum in Scotland – Steve Williams or Paul Munro, 0131 314 6508/7.

Further information about P. ramorum can be found on the Forestry Commission’s website at