Effects of Sediment Burial and Exogenous Nitrogen Input on Biomass Allocation and Antioxidative Enzyme Activities of Suaeda salsa in the Coastal Wetland of the Yellow River Delta

PANG Xiao-die;SONG Hong-li;WANG Yan;Shandong Provincial Key Laboratory of Water and Soil Conservation and Environmental Protection;College of Resources and Environment,Linyi University;

N input;;Sediment burial;;Suaeda salsa;;Biomass allocation;;Antioxidant enzyme activity

[Objective]The aim was to study the effects of exogenous nitrogen input and sediment burial on biomass allocation and antioxidative enzyme activities of Suaeda salsa in the coastal wetland of the Yellow River delta.[Method]In this study,we selected S.salsa which is a pioneer vegetation in the coastal wetland as the research object,and based on the simulation experiment,to research the effects of different N inputs(0,3,6,9 g/m) and sediment burial depths(0,3,6,12 cm) on biomass allocation and antioxidant enzyme activity of S.salsa.[Result]The results showed that root proportion and chlorophyll content of S.salsa increased under the moderate burial depth,which was beneficial to the growth of S.salsa.Appropriate N input also promoted the growth of S.salsa and increased its protein content and total biomass,while excessive burial and N input would inhibit S.salsa growth.N input and sediment burial also influenced antioxidant enzymes activities,and showed that the activity of CAT,POD and SOD increased when the sediment burial is 0 and 3 cm,while the activity of the three enzymes decreased with the increase of stress.When the input of exogenous N was 6 and 9 g/m~2,the activity of the three antioxidant enzymes showed a decreasing trend with the increase of burial depth.Among them,the activity of POD and SOD was significantly reduced when the N input amount was 9 g/m~2 and sediment burial was 12 cm,which were 41.77% and 34.08% lower than the control.CAT activity obtained a minimum value(2.38 U/mg) at the burial depth of 6 cm and the maximum N input(9 g/m~2).The results of ANOVA showed that:N input,sediment burial and its interaction had significant effects on the total biomass and CAT activity of S.salsa,while N input and sediment burial had significant effects on POD activity(P<0.05). [Conclusion]We concluded that the exogenous N input and sediment burial brought by water and sediment regulation had certain influence on the growth of S.salsa in the coastal wetland of the Yellow River estuary. S.salsa could adapt to the changing environment through its own physiological changes within a certain range,but the environmental changes exceeded a certain value would threat the normal growth of S.salsa.