Mountain bikers are being urged to help minimise the impact of a fatal tree disease discovered in Wales.

An outbreak of Phytophthora ramorum has been found in a small number of Japanese larch trees at the Bwlch Nant yr Arian visitor centre, near Aberystwyth, which is home to three single track mountain bike routes.

And mountain bike ranger, Andy Braund, is appealing to mountain bikers to help keep the routes at Bwlch Nant yr Arian open by following some simple bio security measures.

“We are working hard to minimise the impact of this serious disease on our woodlands and the support of the mountain bike community is vital,” said Braund.

“Everyone who works in or visits the affected woodlands is being asked to observe the bio security measures so that they don’t inadvertently spread this pathogen.

“For mountain bikers, this means keeping to the trails and washing their bikes and kit thoroughly to remove all dirt and plant material before they leave the forest – a bike wash is available at the visitor centre.

“They should also wash their clothing between visits to forests.

“Phytophthora ramorum is a serious disease and, by felling infected trees, we hope to limit the production of the spores that spread the infection.

“As Bwlch Nant yr Arian is a popular site, it is also important that we fell infected trees before they die and become unstable, thus presenting a potential risk to visitors.”

P. ramorum is a fungus-like pathogen that kills many of the trees 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.

In an attempt to minimise the impact of the outbreak at Bwlch Nant yr Arian, Forestry Commission Wales will fell up to 60 trees that are currently infected.

The work will take approximately two weeks to complete and will be carried out with as little disruption as possible to visitors.

P. ramorum is not harmful to humans or animals and all walking and mountain bike trails, plus the visitor centre, remain open to the public.

While the felling of infected trees takes place, the last section of the three mountain bike trails will be closed for a short period of time and a diversion put in place.

P. ramorum was first discovered on Japanese larch trees in south west England in 2009. It was then found on larch in public woodlands in south Wales in June 2010.

Further information about P. ramorum can be found on the Forestry Commission’s website at www.forestry.gov.uk/pramorum