3.4 Changes in NSC level over winter
Only N-fertilization significantly affected the over-winter NSC
consumption (post-winter level minus pre-winter level) in shoots but not
in roots (Table S1). Neither D nor N and their interactions changed the
tissue NSC consumption in oak over-winter (Fig. 4a,c), while
N-fertilized beech significantly
decreased the over-winter NSC
consumption in both shoots and roots (Fig. 4b,d). The changes in
sugar/starch ratio were significantly influenced by both, species and
N-fertilization (Table S1). N-fertilization tended to decrease the
sugar/starch ratio in beech, especially in shoots of D3 plants (Fig.
4f,h), while the unfertilized oak saplings seemed to increase the tissue
sugar/starch ratio over winter, especially the D3 plants (Fig. 4e,g).