Phenotypic variability of Fraxinus excelsior L. and Fraxinus angustifolia Vahl under the ash dieback disease in the Czech Republic

Abstract

The study was carried out in the experiment with 16 provenances of common ash (Fraxinus excelsior Linnaeus) and 2 provenances of narrow-leaved ash (Fraxinus angustifolia Vahl) at a series of 5 parallel trial plots established in a gradient from lowland riverine to upland ravine sites. The role of the site, ash species and the provenance of common ash proved to have significant effects on the intensity of ash dieback (ADB) associated with the infection by Hymenoscyphus fraxineus (T. Kowalski) Baral, Queloz & Hosoya at the age of 20 years. Narrow-leaved ash was healthier, surviving and growing better than common ash on the trials situated inside as well as beyond its natural range. The ADB intensity was lower in the medium altitude and more easterly located trial plots with a more continental climate. The provenance of forest reproductive material proved to have a significant effect on the ADB damage and survival rate as well as the growth of ash across the trial plots of the experiment.