强潮区较高纬度移植红树植物秋茄的生理生态特性

Abstract

Ximen island of Yueqing bay,the northern boundary of artificially planted mangroves,was chosen as the study site.Changes of 1-and 4-year-old Kandelia candel at the tidal level of 1.96,1.66 and 1.35 m above the zero tidal level of Yellow Sea(Waterlogging time at this tidal level are 3.18,3.65 and 4.07 h per-tide-cycle respectively) on growth,photosynthetic pigments,activities of protective enzymes in leaves,contents of total soluble sugars and free amino acid and ion contents in leaves and stems were investigated.The results showed that the tidal level of 1.66 m above the zero tidal level of Yellow Sea was suitable for planting Kandelia candel,because the waterlogging time at this tidal level was less than 3.65 h per-tide-cycle.When the tidal level was 1.35 m above the zero tidal level of Yellow Sea,the waterlogging time at the tidal level was 4.07 h per-tide-cycle,which caused a series of effects.A decrease in the contents of chlorophyll,carotenoid,total soluble sugars and free amino acid,the activities of peroxidase(POD) in leaves,and the ratio of K+/Na+ in stems and leaves of 4-years-old Kandelia candel were detected.Moreover,a rapid increase in the contents of malondialdehyde(MDA) in leaves and Na+ concentration both in leaves and stems of 4-years-old Kandelia candel were found.Based on results listed above,a growth retard was detected when the waterlogging time was 4.07 h per-tide-cycle for 4-year-old Kandelia candel.However,this growth retard was not found in 1-year-old Kandelia candel under the same waterlogging time.Therefore,it is concluded that the older Kandelia candel could grow at 1.66 m above the zero tidal level of Yellow Sea,which is due to the maintaining of normal carbon and nitrogen metabolism under waterlogging time(less than 3.65 hours per-tide-cycle) at this tidal level.