Oak decline in the USSR
Further to EPPO 's recent Reporting Service on oak decline in Eastern Europe, we draw attention to a recent article by Oleksyn & Przybyl in the European Journal of Forest Pathology. This describes the considerable extent of oak decline in USSR and stresses that 3 earlier phases this century (1901-1906, 1927-1930, 1941-1944) are now being followed by a longer and more serious phase (1964 to present day). The authors analyze a series of hypotheses on the cause (climatic, sylvicultural, insects, fungal diseases). They conclude that the primary factors weakening trees are unfavorable climatic conditions and in particular lasting droughts. Fungi (Ophiostoma spp.) and insects are seen as significant secondary factors.
Oleksyn, J. & Przybyl, K. (1987) Oak decline in the Soviet Union - scale and hypotheses. European Journal of Forest Pathology 17, 321-384.
European Journal of Forest Pathology.