Soil moisture and light intensity are important ecological factors that affect the growth and distribution of vegetation. In this study, one-year old Amorpha fruticosa seedlings were used as the test material in order to study the combined effects of soil moisture and light intensity on their growth, development and ecophysiological characteristics.
The results showed that the different soil moisture and light intensity remarkably influenced the ecophysiological characteristics of A. fruticosa seedlings. With reduction of soil moisture, the seedlings had slower growth rate and smaller individuals, net photosynthetic rate and transpiration rate reduced, Leaf water saturation deficit(WSD) increased, leaf water loss rate (WLR) decreased, parts of plant biomass accumulation reduced, more photosynthetic products were allocated to root. With the decrease of light intensity, net photosynthetic rate and transpiration rate reduced, chlorophyll (Chl) a, chl b, chl a+b and carotenoids (Car ) increased, while chl a/b, WSD, WSE and WLR reduced, parts of plant biomass accumulation reduced, more photosynthetic products were allocated to stem and leaf growth. Among all the treatments, A. fruticosa seedlings with 80%~75% water-holding capacity of substrate and 100% light density in greenhouse presented the most strong growth vigor, the highest net photosynthetic rate and the largest total biomass accumulation.