Carbon use strategies in shoot and acorn growth of two evergreen broadleaf trees unraveled by seasonal carbohydrate measurements and carbon isotope analysis.

This article focuses on the seasonal dynamics of non-structural carbohydrate (NSC) storage and carbon (C) allocation related to reproduction in two mature evergreen broadleaf tree species, Quercus glauca Thumb. and Lithocarpus edulis Nakai. Through a two-year study measuring starch, soluble sugars (SSs), carbon isotope ratios (δ13C), and biomass in leaves, twigs, and reproductive organs, the research found that reproduction had limited influence on seasonal NSC storage. Both species relied predominantly on newly assimilated photo-assimilates rather than stored NSCs for reproductive growth, as indicated by similar δ13C enrichment in fruit organs and twigs relative to leaves. The study also revealed species-specific sugar compositions and highlighted the role of leaf habit and fruiting phenology in carbon allocation processes in these lucidophyllous evergreen trees.