Table 5 SPEI trend from 1901 to 2016, with values of the lower and upper bounds (lb and ub, respectively) and the p-value (significant, i.e., p-value < 0.05, trends are in bold). In the last two columns, the percentage of cases with an SPEI value equal to or below -1.28 are reported for the periods 1901 to 2016 and 1980 to 2016

From: Changes in tree-ring wood density of European beech (Fagus sylvatica L.), silver fir (Abies alba Mill.), and Norway spruce (Picea abies (L.) H. Karst.) in European mountain forests between 1901 and 2016