Study On Soil Salinity Dynamics In Heavy Salt Area Of Jiangsu Sea Shoal And Salt Tolerance Plants Selection

Two-year track research of heavy salinity soli have been processed a in the Yangkou Port inning shoal of Jiangsu province. The research work mainly contained tow aspects: soil salinity dynamics, and salinity characters under different vegetation types. Meanwhile, salt tolerant plants trails in the Yangkou inning shoal and greenhouse plants experiments of salinity tolerance in the Nanjing Botanical Garden Mem. Sun Yat-sen were arranged, to select plant species which can adapt the Yangkou environment. The results are as follows:(1)Soil salinity dynamicsThe main trend of soil salinity dynamics in Yangkou Port was descendent, except some soil layers. Salinity dynamics range was between -131.6% and88.5%. Deeper layers have presented more fluctuant than the surface ones in salinity; and high level salinity layer also showed the same trend. Na+ and Cl- variance were accorded with the salinity. The salinity level in the plot with cover of vegetation is lower.Soil salinity appeared significant correlation-ship to bulk density and mechanical composition. Salinity showed negative relativity with bulk density and sand proportion, but positive relativity with powder and clay.(2)Soil salinity characters under different vegetation typesAmong the three vegetation types:Seabania,Bulrush and Suaeda salsa, salinity of Seabania is the lowest, but Artemisia is highest. There were significant correlation-ship between salinity and ions; pH presented negative relativity to ions. Established linear equation of salinity and other chemical composition. Compared with natural plants community, the manual vegetation Seabania could remove soil salinity effectively, and improve soli structure.(3)Plants salt tolerance selectionThe results of trails of plants salt tolerant in the Yangkou inning shoal represented: tees such as Robinia,Albizia,Salix,Rhus,Ash,Elliottii,and shrub like Hibiscus,Tamarix,RedRobin,Senna,Malva,were most adaptive to the Yangkou shoal, and shrubs more salt tolerant than trees. These species could tolerant 5‰salinity . The Leguminous plants appeared extreme adaptability.(4)Capability of seeds germination salt toleranceFour plants species seeds germination salt tolerance. Seabania and Hibiscus seeds could germinate normally under 3‰salinity; but Indigofera could only germinate below 2‰. Medicago even could normally germinate when the salinity was at 6‰level. The four species final percentage of germination were significant negative to the soil salinity.(5)The salt tolerance capability of Hibiscus seedlingsThree Hibiscus species appearances of survival rate, growth ability, proportion of tissue dry wet and fresh wet, and Na~+/K~+ of plants tissue have been measured. Hibiscus'moy'grande and Malvaviscus arboreus Cav could tolerant the 6‰salt level while Hibiscus hamabo Sieb.et Zucc could adapt more high than 9‰salt level. Hibiscus hamabo Sieb.et Zucc growth did not affected by salinity level well.