Scientific Reports of the National University of Life and Environmental Sciences of Ukraine

Dendrochronological assessment of common ash stands in areas of intensive dieback

Yulia Babych , Nataliia Puzrina, Oleksandr Bala
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Abstract

The widespread dieback of the common ash (Fraxinus excelsior L.) is one of the most pressing issues, caused by both global climate change and the spread of dangerous infectious diseases. Analysis of how the combination of hydrothermal stress and various types of pathogens affects the viability of stands is critical for developing strategies to conserve forest ecosystems. The study aimed to conduct a comprehensive dendrochronological assessment of the condition of ash stands and to analyse the dynamics of tree radial growth under conditions of varying degrees of pathogen infestation and the influence of climatic factors. The study was based on the collection of growth cores using age-specific borers from trees in various condition categories: healthy (control), affected by sulphur-yellow tinder fungus, canker tumours, and in areas of intensive dieback. Analysis of annual ring width was conducted by scanning the samples and subsequently processing them in the specialised software ImageJ with the ObjectJ plugin. Climatic analysis was conducted using archived temperature and precipitation data for the period from 1979 to 2025. A steady trend towards climate warming (an increase in the mean annual temperature of 2.5-3.0°C) and moisture deficit was identified, creating conditions of chronic hydrothermal stress for ash trees. The study established that trees in areas of intense dieback show a sharp reduction in radial growth, which is no longer linked to the climatic trend due to pathological weakening. Infection by tinder fungi and canker tumours leads to a gradual decline in growth or high variability in growth rates; however, it has a less critical impact on viability over short time periods compared with halar necrosis. The obtained data can be used to apply radial growth indicators as an accurate indicator of stand condition for the early diagnosis of forest degradation. The results can be utilised by forestry enterprises to optimise sanitary measures and predict the resilience of ash forests under changing environmental conditions

Keywords

radial growth; climate change; forest pathogens; halar necrosis; annual rings; stand vitality; hydrothermal stress

Suggested citation
Babych , Yu., Puzrina, N., & Bala, O. (2026). Dendrochronological assessment of common ash stands in areas of intensive dieback. Scientific Reports of the National University of Life and Environmental Sciences of Ukraine, 22(3),147-161. https://doi.org/10.31548/dopovidi/3.2026.147
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