Scottish Forestry has today confirmed that Phytophthora pluvialis will no longer be treated as a quarantine pest for regulatory purposes, removing the need for statutory action to be taken at infected sites.
The move, which applies across Great Britain from today (4 March), follows on from the latest scientific evidence and expert review into the pathogen.
The UK Plant Health Risk Group found that risks from the pathogen are low and therefore it does not meet the criteria of a quarantine pest.
James Nott, Scottish Forestry’s Head of Tree Health said:
“The pathogen was first found in Cornwall back in 2021 and since then all the countries have jointly taken a precautionary approach when dealing with pluvialis. This approach was essential until we found out more about the pathogen and its implications.
“The latest research provides confidence that Phytophthora pluvialis presents a lower level of risk than originally feared. It is therefore appropriate and proportionate to lift statutory restrictions while we still continue careful monitoring.
“Protecting Scotland’s natural environment remains a priority, and we will continue surveillance to ensure any change in risk is identified early. Please continue to report any suspected findings via TreeAlert.”
Existing Statutory Plant Health Notices will be withdrawn and demarcated areas surrounding known infection sites will be lifted.
Phytophthora pluvialis was first detected in 2021 and subsequently identified at forest sites across Great Britain, including in Scotland.
At the time, the UK Plant Health Risk Group concluded that the pathogen met the criteria to be treated as a quarantine pest, allowing controls and statutory measures to be introduced while further research was undertaken by Forest Research.
Following interim findings in 2023, restrictions on the movement of timber were partially lifted after evidence showed the risk of spread via timber was low. Restrictions on the movement of living trees in demarcated areas remained in place pending further research.
The latest scientific assessments considered the pathogen’s distribution, natural spread and impact. The evidence indicates that:
- no infections have been found in plants for planting at nurseries
- spore production is lower than that of the highly infectious Phytophthora ramorum
- although spores can be transported in soil, they are relatively short-lived
- damage does not generally affect timber quality, though some reduction in growth rates can occur
On this basis, the UK Plant Health Risk Group concluded that Phytophthora pluvialis does not meet the criteria to be classified as a quarantine pest in Scotland and across the rest of Great Britain.
The updated approach also brings Great Britain into line with the current position in Europe. The pathogen is not classified as a quarantine pest in the EU, and following a finding and investigation, Belgium has recently taken the decision not to regulate this pathogen.
Further information can be found on Scottish Forestry’s website.
