Along the western side of Great Britain, a plant disease is becoming an increasing problem for woodland owners as it gradually spreads and infects larch trees. It is a fungus-like pathogen that causes extensive damage and mortality to trees and other plants, but is particularly virulent where stands of larch are growing in timber plantations. Since 2009, when it was discovered infecting and killing large numbers of Japanese larch trees in South West England, the Forestry Commission has developed a surveillance programme to monitor the spread of the infection.
The disease is regularly referred to by its scientific name Phytophthora ramorum and was diagnosed at Pullabrook Woods by the Forestry Commission’s Plant Health Team earlier in the summer. After initial on-site tests, samples were taken to the Forestry Commission laboratory at Alice Holt in Surrey where the infection was confirmed. Since then, a Statutory Plant Health Notice has been served on the Woodland Trust which specifies that, to reduce the chances of continuing infection, the stand of larch must be clear felled before March 2017.
Sadly, this process is becoming more frequent across the region and, in areas such as Pullabrook Woods, the conservation management plan has had to be radically changed. The Woodland Trust’s preferred method of Continuous Cover Forestry allows for the gradual restoration of broadleaved woodland as the coniferous trees are methodically removed. This Plant Health Notice will accelerate the felling programme and will result in a sudden dramatic change on the local ecosystem. To minimise this effect, a replanting programme will begin after the larch has been cleared to re-establish a more natural broadleaved woodland. Fortunately, there are already remnants of ancient woodland under the larch as it stands. Shrubs, small trees and seedlings are all visible among the wildflowers and other woodland plants at ground level. Along with newly planted saplings, they will restore the health of the woods in years to come.
As well as the activity within Pullabrook woods this coming winter, a number of haulage vehicles will be taking the timber away (A382/A38) towards the timber mills around the region. This can only be done by licensed hauliers who follow strict bio-security regulations to minimise the risk of spreading the disease. Scientific knowledge shows that the infection will remain in the bark of the larch and, as long as it is disposed of correctly, the infection will not spread further. The FC guidance states that “A principle of this approach is that co-products (bark in particular) from infected material must be processed in such a way that it would prevent infection from entering into the horticultural trade, through the use of bark based composts.”
Unfortunately, for those who regularly enjoy the peace and freedom of Pullabrook woods, a temporary restriction of access commenced in December 2016. On-site signage will highlight the areas of felling work and the higher route through the woods will be closed until the 16 December. Work will be paused over Christmas, with all access routes open from 17 December – 4 January. The felling work will resume in the New Year, when you may continue to use the lower routes, but please take care to avoid any machinery and stacks of timber while the contractors are working.
The Woodland Trust would like to reassure local people and visitors that they are experienced in managing similar outbreaks of Phytophthora ramorum at other sites and will be handling this outbreak in a professional way. The Trust would like to thank visitors for their cooperation.
Written by Matt Parkins
To find out more about the distribution of Phytophthora ramorum outbreaks in the UK follow the link to the FC website