Understory Vegetation of Ash‐Alder Woods and Alder Carrs Attacked by Alien Tree Pathogens: A Local Study From The Czech Republic

ABSTRACT This report briefly describes the vegetation of ash and alder woodlands affected by alien pathogens Hymenoscyphus fraxineus and Phytophthora alni in the Natural Monument ‘Peklo’ in North Bohemia. Vegetation was explored by 30 randomly placed samples. The data were analysed using the ordination technique (NMDS) and correlations with damage proxies were explored. The more and longer damaged sites differ from less damaged woodlands mostly in the presence of light‐demanding species. The pathogens contribute to the overall heterogeneity of the vegetation at the current stage of their invasion.