An outbreak of Phytophthora ramorum (P. ramorum) was recently found affecting a small number of Japanese larch trees in Clocaenog Forest, Denbigh.
Work is now underway to fell the infected trees to try to prevent the spread of this serious tree disease.
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.
Steve Cresswell from Forestry Commission Wales, which manages Clocaenog Forest on behalf of the Welsh Assembly Government, said, “Phytophthora ramorum is a fatal tree disease and, by felling infected trees here, we hope to limit the production of the spores that spread the infection and therefore minimise the impact of the outbreak.”
Access to small sections of the forest will be restricted to the public while the felling operations are carried out.
P. ramorum is not harmful to humans or animals and, to avoid inadvertently spreading the pathogen, visitors to infected woodlands such as Clocaenog Forest 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.
There is no evidence to suggest that the presence of P. ramorum in a tree makes its timber unusable and there is no risk of further spread from wood that has been processed.
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.
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, where work to fell the infected trees is underway.
Forestry Commission Wales staff will continue to monitor trees for signs of infection but symptoms may not become evident until later this spring when larch trees – which are deciduous conifers – renew their needles.
Forestry Commission Wales has also asked for the support of private woodland owners in looking out for early signs of P. ramorum infection in their trees. To report suspected infection or to find out about the support available to them, woodland owners should contact Forestry Commission Wales’s Grants & Regulations Office on tel: 0300 068 0300 or email: [email protected].
