The Forestry Commission is urging woodland managers, landowners and the forestry industry to remain vigilant following further findings of Phytophthora pluvialis in areas across England.
Extensions to the existing demarcated areas in Devon and Cornwall have been made following further identifications of the pathogen in these areas. Investigations are ongoing into the first reported cases of the pathogen in woodlands in Surrey and, following further findings in Wales, a new demarcated area has been introduced in Herefordshire to combat any potential spread.
The UK Chief Plant Health Officer has confirmed these findings following extensive surveillance activities by the Forestry Commission and other parts of the UK Plant Health Service.
Phytophthora pluvialis is a fungus-like pathogen known to affect a variety of tree species, including western hemlock, Douglas fir, tanoak and several pine species (in particular radiata pine). It is reported to cause needle cast (where needles turn brown and fall off), shoot dieback, and lesions on the stem, branches, and roots.
Phytophthora pluvialis has been detected on mature western hemlock and Douglas-fir trees at the affected sites, and has been confirmed as the direct cause of the observed symptoms.
Forestry Commission, Forest Research and the Animal and Plant Health Agency are continuing to conduct further surveillance and diagnostic analysis to understand more about the pathogen and ensure that any required control measures are swiftly undertaken to stop its spread. This includes extensive ground and aerial surveillance as part of a UK-wide survey, and comprehensive research and modelling to explore factors such as climatic and potential species susceptibility and to help inform the management response.
Nicola Spence, the UK’s chief plant health officer, said: “We are taking robust and swift action against the findings of Phytophthora pluvialis at these sites, as part of our well-established biosecurity protocol for tree pests and diseases.
“I urge all sectors to support efforts to tackle this pathogen by checking the health of western hemlock and Douglas-fir trees. Key symptoms to look out for are lesions on the stem, branch or roots. Any sightings should be reported to the Forestry Commission via its TreeAlert online portal.”
The introduction and extensions of demarcated areas help to prevent the accidental movement of tree pathogens. Additional restrictions requiring pre-notification of felling of susceptible material within demarcated areas were introduced in December 2021 and continue to apply to all demarcated areas.
Further information on tree pests and diseases, and how to identify them, is available here.
Landowners are asked to report any suspect trees via TreeAlert.