EPPO Platform
on PRAs

Rapid Pest Risk Analysis (PRA) for: Phytophthora austrocedri


This rapid PRA shows: 

Potential for further entry is: Likely.

Potential for further establishment is: Very likely.

Economic impact is expected to be: Small, based on current known host range. 

Environmental impact is expected to be: Large, due to the host being of high ecological significance within the UK. 

Social impact is expected to be: Medium, based on societal value of juniper as a native conifer. 

Endangered area: Extensive, and including sites with high biodiversity values that are already vulnerable. The importance of juniper is recognised and it has been assigned its own species action plan in the UK Biodiversity Action Plan process (Anon., 2007). 

Risk management: Practices are available to manage the risk (see 15) which are largely based on managing other Phytophthora pathogens but would require evaluation to measure their effectiveness in relation to P. austrocedri

Key uncertainties and topics that would benefit from further investigation: 

- Improved understanding of the epidemiology and distribution of the pathogen in Britain including key dispersal mechanisms and distance of spread 

- An understanding of the relative risk of propagating juniper by berries or cuttings to inform restoration programmes 

- Understand climatic, edaphic and hydrological factors affecting pathogen establishment and spread in order to identify ‘low risk’ sites that could be targeted for conservation measures 

- Examine the genetic structure of P. austrocedri populations in Britain to confirm its status as an introduction and to determine whether ‘source’ populations and routes of spread can be identified 

- Determine whether healthy juniper trees located within areas of heavy infection have natural resistance to the pathogen. If so these individuals could form the basis of a resistance breeding programme for site restoration. 

- Clarify pathogenicity of P. austrocedri on Leylandii cultivar ‘Gold Rider’ following the unconfirmed finding of this pathogen on this host.

The results of this research could be used to review the PRA.


  • Phytophthora austrocedri


  • Austrocedrus chilensis
  • Callitropsis nootkatensis
  • Chamaecyparis lawsoniana


Type File Size
Pest Risk Analysis Download 619,32kB

PRA Area

  • United Kingdom