3.3 Post-winter NSC after drought duration treatment last growing season
The post-winter NSC levels in both shoots and roots were significantly affected by drought duration treatment in the previous growing season (Table 2). The post-winter root NSC was species-dependent (P < 0.05; Table 2), and species interacted with N-fertilization to influence the post-winter shoot NSC (P < 0.05; Table 2). There was no direct effect of N on NSC for both species (Table 2). Both shoots and roots of D3 oak had significantly lower post-winter NSC levels compared to the other drought treatments (Fig. 3d,e), mainly caused by both lower sugars and starch levels for shoots (Fig. S6a,c) and by lower sugar levels for roots (Fig. S6b). In beech only shoots of D2 and D3, due to both lower sugar and starch levels (Fig. S7a,c), showed significantly lower post-winter NSC levels compared to the other drought treatments (Fig. 3i,j). N-fertilization significantly increased shoot NSC in oak (Fig. 3d) but it had no effects on shoot (Fig. 3i) and root NSC (Fig. 3j) in beech.