Summary

Invasive pathogens present a significant threat to the UK forestry industry. Recent epidemics have highlighted the risks of overreliance on a narrow range of plantation forestry tree species. FR research trials have been established to assess alternative forestry species which have an overseas origin, but which might be suitable for production forestry in the UK. Key to their suitability will be the extent to which these species remain resilient when exposed to endemic pathogens present in the UK. This work aims to evaluate the pathogen threats to alternative forestry species and provenances in established trials and tree nurseries.

Research Objectives

  • Identify the key pathogen threats to a range of alternative forestry species and provenances planted out at trial sites in the UK.
  • Assess the potential for variable susceptibility to existing local pathogens between a range of alternative species and provenances planted out at different geographical locations in the UK.
  • Investigate a new fungal pathogen causing foliage necrosis on coast redwood and giant redwood at species trial sites.
  • Investigate the pathogens damaging Douglas fir in tree nurseries and assess methods for improving nursery biosecurity practices.
  • Advise the forest industry on best species and provenance choices based on current and future biotic threats

Latest Update

In 2021 and 2022, pathogen impacts were assessed on tree species and provenances present across four experimental trial sites in Britain. Significant variability was detected among species and provenances, with the pines being heavily impacted by the needle blight pathogen Dothistroma septosporum. Compared with native Scots pine, non-native radiata pine and maritime pine suffered higher disease impacts, with the destructive shoot pathogen Gremmeniella abietina detected on both hosts. These data suggest that use of native Scots pine provenances is advisable over non-native alternatives in future forestry planting. The needle cast pathogen Nothophaeocryptopus gaeumannii was detected on all provenances of Douglas fir at three of the sites, resulting in significant foliage necrosis. A new pathogen, Phacidiopycnis washingtonensis, was found causing foliage necrosis on coast redwood and giant redwood at several sites. This pathogen is currently being evaluated to determine whether it may be a recent introduction into the UK and to assess its pathogenicity on these hosts. Fungal and oomycete pathogens infecting Douglas fir in plant nurseries have also been investigated with a view to improving biosecurity protocols when raising Douglas fir.

Our Involvement

FR is leading the work

Downloads

Pathogen impacts and implications for species diversification in UK forestry

Morton et al. 2025 Forestry 2. Journal article published in Forestry detailing outcomes of the species trials assessments

PDF | 2.23 MB

Funding & Partners

  • Funded as part of the Forestry Commission Programme 7 ‘Tree Health and Biosecurity’