Forest Research
Woodland managers, landowners, the forest industry and tree nurseries are being urged to remain vigilant after the Forestry Commission (FC) and Forest Research (FR) identified the tree pathogen Phytophthora pluvialis in woodlands in Cumbria and south-west England.
The UK Chief Plant Health Officer confirmed the findings, following routine Forestry Commission plant health surveillance activities.
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.
Although Phytophthora pluvialis has been detected on mature western hemlock and Douglas-fir trees at these sites, it is as yet unknown if the pathogen is the direct cause of the observed symptoms. Investigations are ongoing to determine whether other factors are at play.
Forestry Commission, Forest Research and the Animal and Plant Health Agency are rapidly conducting 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 Chief Plant Health Officer, said:
We are continuing to take swift and robust action against the findings of Phytophthora pluvialis, as part of our well-established biosecurity protocol used 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 for are lesions on the stem, branch or roots. Any sightings should be reported to the Forestry Commission via its TreeAlert online portal.
Following further findings, the Forestry Commission will introduce an extended demarcated area in Cornwall and Devon to help prevent the accidental movement of the pathogen. Additional restrictions requiring pre-notification of felling of susceptible material within the demarcated area have also been introduced and will apply to all current demarcated areas.
The two Notices will come into force on 10 December reflecting these changes.
Further information on tree pests and diseases, and how to identify them, is available here.