“Gleichläufigkeit” (GLK) between tree-ring width of beech trees in the thinned plot and fruit body numbers, with time shifts up to 3 y between the tree-ring and fruit body data (Lag 0 to Lag 3; fruit body data shifted forward relative to tree-ring data). The number in brackets behind the mycorrhizal categories in the legend gives the correlation coefficient and the p-value between the number of fruit bodies and the tree-ring width of beech trees for Lag 0. (* p < 0.05, ** p < 0.01, *** p < 0.001.)