Abstract
Ash dieback, caused by the invasive fungal pathogen Hymenoscyphus fraxineus, has become a serious threat to ash trees (Fraxinus spp.) and ash-related ecosystems in Europe. The fast emergence and expansion of this new disease has called for an intensive investigation, which resulted in a large number of research projects in Europe. Recently, as a result of the European cooperation and exchange programme FRAXBACK, numerous reports containing detailed information about the situation of ash dieback in different countries and related research have been published. For this review, we performed a systematic analysis of these country reports. We focussed on differences and similarities between European regions and countries regarding the importance, genetics and resistance of ash, the spread, monitoring, impact and management of the disease and on factors that have an influence on its severity. By including most recent scientific literature, this review provides a concise yet substantial overview about ash and ash dieback in Europe.