The impact of ash dieback on veteran trees in southwestern Sweden

Ash dieback (Hymenoscyphus fraxineus) is a fungal disease which affects ash throughout Sweden. Monitoring to study of the impact on veteran trees was undertaken in southwest Sweden 2009, 2011, 2013, 2015, and 2020. The found that 94.5% observed were affected by 2020 compared with 62% 2009. 70 studied have died (21%) since monitoring began. In 2009 there no relationship between girth dieback, but correlation statistically significant. 2020, also for first time during monitoring, shade significantly more standing open. This difference not detected 2013 or 2015. effect pollarded has varied years studied, longer any significant non-pollarded trees. There however mortality rates groups trees, recent times having highest mortality. Therefore, recommendation relation all pruning should be avoided. Pollarding only done pollards are regular cutting cycle showing symptoms dieback. If possible, clear around old if they shaded conditions. Given relatively few studies results this relevant outside management non-woodland situations. Key words: pollards, Hymenoscyphus fraxineus,