Mean number of flushes per tree 2007–2009.

Air warming (AW), drought (D) and soil effects on the number of flushes per tree. Data are separately shown for each growing season (means ± SE). Data of the different provenances were pooled before statistical analyses (n = 8). Different letters indicate significant differences between respective treatment means on the same soil, an asterisk * indicates significant differences between acidic and calcareous soil for the same treatment (P<0.01).