Abiotic factor that contributes to oak decline
For very localised, but nonetheless damaging episodes of oak decline and dieback in England, severe wind events have been identified as the primary cause because of the severe drought that can be induced.
In one local episode in 1952, the wind blew continuously for 2 months in June and July and for 35 of those days the wind speed was between 20-40 km per hour, imposing a very high dehydrating pressure on the trees. Affected trees never recovered after this stress event, and insects and mildew then further damaged the weakened trees contributing to their demise.
Another episode of serious dieback occurred in 1989 to 1994, when drought damage was considered to be a key factor and the weakened trees were then attacked by the two spotted oak buprestid beetle, Agrilus biguttatus, which resulted in tree death.