Symptoms of Oak Decline Dependent on Weather Conditions : Disease/Environment Interactions in Forest Decline. Proceedings of a Workshop of the Working Party Disease/Environment Interactions in Forest Decline IUFRO 7.02.06, Vienna, Austria, March 16-21, 1998

1999

S.105-111

3 Tab., 26 Lit.

Unselbständiges Werk

200085354

In the Krotoszyn Forest District (Central-West Poland) valuable oak stands (mostly Quercus robur L.) are severely affected by oak decline, caused by various reasons, both biotic and abiotic. The dead-standing tree volume shows reciprocal dependence on previous year precipitation and previous winter (December-February) air temperature - after very rainy season the dead-standing tree volume decreases and after severe winter - increases. In three oak stands (age 141, 126 and 75) the following symptoms were observed in 1995-97: foliage reduction, branch dieback and exudates on trunks. The exudates on trunks. The exudates on trunks, which appeared only in late summer, were most precipitation-dependent, while foliage reduction and branch dieback seem to depend more on winter air temperature and increase after severe winters.