3.2 Pre-winter NSC after drought duration treatment
The pre-winter NSC levels in leaves differed significantly with species (Table 2). The shoot NSC levels, however, did not vary with species but were significantly affected by both drought treatment and N-fertilization (Table 2). The root NSC was significantly influenced by species and drought duration (Table 2). In addition, N-fertilization significantly interacted with species to affect the NSC levels in both shoots and roots (Table 2). Compared to the D0, D1 and D2 treatments, oaks in D3 had significantly higher leaf NSC levels (Fig. 3a), mainly caused by higher sugar concentration (Fig. S4a), but significantly lower shoot NSC (Fig. 3b) mainly resulting from significantly lower starch levels (Fig. S4e). The root NSC of oak tended to decrease with increasing drought duration (Fig. 3c), due to both decreasing sugar and starch levels (Fig. S4c,f). For beech, both leaf and root NSC levels did not change with drought (Fig. 3f,h) but shoot NSC decreased with increasing drought duration (Fig. 3g) caused by both decreased sugars (Fig. S5b) and starch (Fig. S5l). N-fertilization significantly increased the shoot NSC in oak (Fig. 3b), whereas it significantly decreased NSC levels in shoots (Fig. 3g) and roots (Fig. 3h) of beech.