Fig. 2

Timing and dynamics of cambial activity and xylogenesis in stems of Cedrus libani during 2013. Number of cells in the cambial zone, in radial enlargement phase, in wall thickening phase, mature cells and total number of xylem cells are shown for the German (O1) and the four Turkish sites (T1 –T4). Error bars represent standard deviations among trees per site. Periods of cambial, enlargement and wall thickening activity are highlighted in gray. Dotted vertical lines indicate the time when first mature cells could be observed, dashed vertical lines the time when enlarging cells emerged thus wood formation was initiated