Work is underway to fell trees infected by Phytophthora ramorum (P. ramorum) in two woodlands near Neath.
Penhydd Forest, within Afan Forest Park, and Crynant Forest are two of the sites in South Wales where P. ramorum was found in Japanese larch trees earlier this year.
Access to sections of both forests will be restricted to the public until March 2011 while the felling operations are carried out.
P. ramorum is a fungus-like pathogen that kills many of the trees that it infects. Infected Japanese larch trees produce high numbers of the spores that spread the disease, with the result that a lot of these trees can become infected very quickly.
P. ramorum is not harmful to humans or animals and, to avoid inadvertently spreading the pathogen, visitors to infected woodlands such as Penhydd and Crynant are asked to observe some simple biosecurity precautions. These are explained on signs onsite and include keeping to paths, keeping dogs on leads, cleaning footwear and not taking any plant material away.
Jonathan Price from Forestry Commission Wales, which manages Afan and Crynant forests on behalf of the Welsh Assembly Government, said, "Phytophthora ramorum is a serious tree disease and, by felling infected trees in these two woodlands, we hope to limit the production of the spores that spread the infection and therefore minimise the impact of the outbreak."
The contractors harvesting the trees will follow biosecurity precautions when handling the logs and transporting them to saw mills that have been licensed to receive logs from infected forests.
There is no evidence to suggest that P. ramorum's presence in a tree makes its timber unusable and there is no risk of further spread from wood that has been processed.
All timber from the trees harvested at Afan and Penhydd forests will be sold to local timber merchants and used for various wood products such as logs, chipboard and biofuel.
P. ramorum was first discovered on Japanese larch trees in Great Britain in 2009 in South West England. It was then found on larch in public woodlands in South Wales in June 2010.
Forestry Commission Wales staff will continue to monitor trees for signs of infection but symptoms may not become evident until next spring when larch trees – which are deciduous conifers – renew their needles.
Further information about P. ramorum can be found on the Forestry Commission’s website at www.forestry.gov.uk/pramorum.
NOTES TO EDITORS
1. P. ramorum is a ‘quarantine’ organism under European Union law and its suspected presence must be notified to the relevant authorities (the Forestry Commission, Fera, the Welsh Assembly Government or the Scottish Government). It was first found in Britain on a viburnum plant in a nursery in 2002.
2. P. ramorum can kill many of the plants that it infects, but symptoms vary according to the species. On Japanese larch (Larix kaempferi) trees, 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. Infected Japanese larch trees produce particularly high numbers of the spores that spread the disease – five times the level produced on rhododendron - meaning the disease can quickly affect a large number of trees and shrubs.
3. P. ramorum has not been found infecting any European larch (Larix decidua) or hybrid larch (Larix x eurolepsis) trees, which are the other two species of larch grown in Britain, but these species are being kept under close surveillance.
4. P. ramorum can be spread on footwear, vehicle wheels, tools and machinery that have been used in infected forests, or by the movement of infected plants. It can also be spread in rain splash, mists and air currents.
5. P. ramorum was first discovered on Japanese larch trees in Great Britain in 2009 in South West England. It was then found on larch in South Wales in June 2010 in public woodlands in the Afan Valley, near Port Talbot, in the Garw Valley, near Bridgend and in the Vale of Glamorgan. Felling of infected larch trees in South Wales is underway and Forestry Commission Wales is working with timber processors and others to ensure biosecurity measures are in place to allow logs from the infected trees to be taken to mills for conversion into timber.
6. P. ramorum has not been found on any trees in Scotland.
7. P. ramorum is not harmful to humans or animals.
8. P. ramorum causes the disease known as "sudden oak death" in the USA, where it has killed millions of American native oak and tanoak trees. However, this name is a misnomer in Britain, where laboratory tests have shown that our two native species of oak, sessile and pedunculate oak, are much more resistant to P. ramorum than their American cousins. Fewer than five native oak trees have been confirmed with P. ramorum infection in Britain.
9. 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.
10. Larch is a durable, versatile timber that tolerates changes between wet and dry conditions very well, and resists rotting when used in the ground. It is therefore in demand for outdoor uses such as fence posts, fence panels, exterior wall cladding, boats, sheds and furniture, as well as indoor uses such as flooring and chipboard. It is easily stained, worked and finished. Complete figures are not available for Japanese larch numbers alone, but all three larch species together cover an estimated 134,000 hectares in Britain, or about 5 per cent of total woodland. Individual country figures are:
- Wales – 23,000ha / 8 per cent;
- England – 43,000ha / 4.3 per cent;
- Scotland – 65,000 ha / 5.1 per cent.
(To convert hectares to acres, multiply by 2.47)
11. About 14 per cent of Wales is covered by woodlands. Of this, 38% (126,000 hectares/311,000 acres) is owned by the Welsh Assembly Government. Forestry Commission Wales is the Welsh Assembly Government’s department of forestry and manages these woodlands on its behalf. Forestry Commission Wales provides advice on forestry policy to the Minister responsible for forestry. It provides grant aid to other woodland owners and regulates forestry by issuing felling licences. It is also part of Forestry Commission GB and contributes to the international forestry agenda. More information on the woodlands of Wales is available on www.forestry.gov.uk/wales.
12. In July, the Forestry Commission announced a £600,000 support package for woodland owners 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.
For information about P. ramorum:
• in Wales - Mary Galliers email@example.com, 0300 068 0300;
• in Great Britain overall – Charlton Clark firstname.lastname@example.org; 0131 314 6500