Investigation into the causes of Alder mortality in Scotland

Project Lead: Steven Hendry
Host Institution: Forest Research, Royal Botanic Garden Edinburgh
Project Date: 1 April 2022 to 30 November 2022
Reference Number:
Alder with phytopthora alni symptoms. Image by Andrej Kunca, National Forest Centre - Slovakia,
Originally raised as a plant health issue of potential concern, the health of Alder trees in Scotland was initially investigated in project PHC2019/09: Health status of Alder in Scotland. This preliminary study found that there could be a legitimate concern over Alder that may have complex causes (several biotic and abiotic stresses were noted), and the timeline of these health issues (gradual or rapid) was unclear. Further scoping and examination of the problem by established experts was recommended, leading to this project. The project will conduct:
• Expert visitation of sites to seek evidence of problems with alder health, gain some understanding as to possible causes, and identify key dimensions of a thorough study should this prove warranted. Lab work to confirm field diagnoses.
• Preliminary citizen science request inviting site-specific records of concern over alder health (potentially via the trained Observatree volunteer network to gather data), with analysis to identify any geographic clustering.
• Produce recommendations for further work including; refined survey methodologies for widespread application by interested organisations; identification of potential candidate sites for detailed study over time, and; a discussion document on risks to existing alder of expansion of riparian woodland.
Institution: Forest Research
Impact Officer: Horticulture and the Natural Environment
Institution: Royal Botanic Garden Edinburgh