Abstract:In order to explore the effects of eutrophic waterlogging and post-waterlogging drought on the tolerance of terrestrial woody plants, the control (CK), nutrient (H), waterlogging (W) and eutrophication waterlogging (WH) treatments were set in the first stage. In the second stage, control-drought (CKD), nutrient- drought (HD), watering-drought (WD) and eutrophic watering-drought (WHD) treatments were set up to study the effects of different water and nutrient treatments on the growth and physiology of one-year-old Dalbergia odorifera seedlings. The results showed that D. odorifera had high survival under all treatments; the seedlings exhibited the highest biomass, net photosynthetic rate and total chlorophyll concentration under H treatment. In contrast, both W and WH treatments significantly reduced stem height increment, total biomass, net photo- synthetic rate, stomatal conductance, total chlorophyll content and leaf water potential, but significantly increased the activities of superoxide dismutase (SOD), peroxidase (POD), and contents of H2O2 and soluble protein. Notably, the impact of W stress was more pronounced than that of WH stress. Compared with the first stage, the biomass increment decreased significantly under both of CKD and HD treatments, but which showed the opposite trend under WD and WHD. Furthermore, compared with CKD and HD treatments, net photosynthetic rate significantly increased, while SOD activity and H2O2 content decreased under WD and WHD. Moreover, compared with WD, biomass increment, total chlorophyll content and POD activity increased under WHD, but Car content decreased. Therefore, it was demonstrated that nutrient supply could alleviate the negative effects of waterlogging on seedling growth of D. odorifera to a certain extent, and early waterlogging, especially eutro- phication waterlogging, was conducive to biomass accumulation of seedlings under later drought condition.
