Abstract:Phenotypic plasticity is of great ecological significance to the survival of plants in heterogeneous habitats. With phenotypic plasticity, plants can maximize access and effectively utilize resources in heterogeneous habitats. This study, based on large-scale analyses, discussed the phenotypic plasticity of Distylium chinense leaves and its soil environmental factors, which aimed to provide a basis for the protection of D. chinense and restoration of ecological environments in the riparian zone. The phenotypic plasticity of the main structural characters of leaves of 36 D. chinense communities and their relationship with soil environmental factors were investigated from 3 heterogeneous habitats (natural riparian, anti-seasonal water level fluctuation, and no water level fluctuation zones) in the Three Gorges Reservoir Region. Leaf traits, including leaf length (LL), leaf width (LW), leaf area (LA), leaf dry weight (LDW), and specific leaf area (SLA), were analyzed with significance analysis and their allometric relationships were determined. The relationships between leaf traits and soil environmental factors were evaluated by canonical correspondence analysis (CCA). The results showed that there were significant differences (P < 0.05) in the five functional traits (LL, LW, LA, LDW and SLA) among heterogeneous habitats, and the mean of the coefficient of variance was 4.80%-26.12%. LW and LL, LDW and LL, LDW and LW, and LDW and LA showed significant allometric relations of power functions among heterogeneous habitats. Allometric coefficients (lg β) among 36 communities showed highly significant differences (P < 0.01), the allometric index (α) expressed the same regularity:LL and LW α < 1, LDW and LL, LW α > 1, LDW and LA α≈1. Thus the growth rate of leaf traits was:LA ≈ LDW > LL > LW. The CCA results showed that total phosphorus (TP), total nitrogen (AN), available potassium (AK), and soil water content (SWC) were the main factors affecting D. chinense leaf phenotypic plasticity, which resulted in the adaptation of D. chinense to adverse flooding habitats. The leaf phenotypic plasticity and allometric growth pattern of D. chinense in heterogeneous habitats showed wide ecological amplitude under different hydrological regimes. In addition, the soil was lack of N and K in the Three Gorges Reservoir. The addition of N and K during vegetation restoration could balance soil nutrition, which could promote D. chinense growth.