Responses Of Sprouting And Growth Of Zizania Latifolia To Habitat Change In Songnen Plain

In recent years,climate change and human activities have led to frequent occurrence of extreme hydrological events and intensified accumulation of soil salinity,which has caused increasingly severe flooding and salt stress on the wetland plants in Songnen Plain.Therefore,the wetland vegetation in Songnen Plain degradation rapidly.In order to maintain the stability of the saline-alkaliized wetland ecosystem and restore the vegetation of degraded wetlands,the response of wetland plants to different hydrological conditions and salinity conditions has become a key issue that requires urgent research.In this regard,this study investigated and analyzed the current species composition,community characteristics and their relationship with habitat factors of the natural Zizania latifolia community in the western Songnen Plain(taking Momoge Nature Reserve as an example),and conducted flooding-salinity interactive experiment to explore the rhizome bud sprouting and seedling growth characteristics of Z.latifolia under different flooding depths and salinity conditions,in order to show the adaptive strategies and mechanisms of the growth and reproduction of Z.latifolia under different habitat conditions,so as to find out the flooding and salt tolerance potential of Z.latifolia and the reasons for distribution and degradation of natural Z.latifolia communities in the western Songnen Plain.This research can make up for the lack of research on the important plants in wetlands under saline-alkali conditions,and provide a scientific basis for the protection and restoration of saline-alkali wetlands in the western Songnen Plain.The results show that:1)In Songnen Plain,Z.latifolia is generally grown in alkalescence brackish wetlands with water depth of 5-30 cm.The leaf area,specific leaf area and underground biomass of Z.latifolia are significantly different among different habitats,but the plant height and aboveground biomass are not significantly different.Aboveground biomass is mainly controlled by the soil total nitrogen content and salinity.Plant height is controlled by the water total nitrogen content.While the remaining indicators are not affected by the test habitat factors.2)With the increase of the depth of flooding,the final germination rate and survival rate of wild rhizome buds decreased significantly.The AGR and seedling height of newly germinated seedlings increased significantly,while the average germination time increased first and then decreased.The germination time is the smallest,and it is the largest when flooded 5 cm.Salinity did not have a significant effect on the final germination rate and survival rate of the root rhizome buds.However,with the increase of salinity,the average germination time decreased first and then increased.It was the maximum when the salinity was 0 mmol / L.When the degree is 5 mmol / L,the minimum value is reached;AGR and seedling height increase first and then decrease,and reach the maximum value when the salinity is 5 mmol / L.The interaction between flooding and salinity only had a significant effect on seedling height.It can be seen that the initial germination stage of Z.latifolia rhizome is a stage sensitive to flooding,and at the same time it is highly tolerant to saline-alkali stress;while the subsequent initial growth stage of seedlings is more sensitive to salinity,but the salinity of 5 mmol / L The bottom always grows well.3)With the increase of flooding depth,plant height and above-ground biomass of Z.latifolia seedlings increased significantly,while rhizome length,root length,total biomass,underground biomass and root-to-root ratio all decreased significantly,and leaf area showed a downward trend after a rise.With the increase of salinity,plant height,leaf area,rhizome length,root length,total biomass,and aboveground and underground biomass of Z.latifolia seedlings significantly decreased.The flooding depth and salt stress have a certain synergistic effect,and the interaction between the two has a significant level of influence on plant height and aboveground and underground biomass.In general,Z.latifolia can survive in the 60 cm flooding depth and 100 mmol / L salinity range set by the experiment,and its growth conditions under different stress conditions show obvious differences.