Urban Salinization and Its Ecological Remediation Principles

With world population growth, urbanization is speeding up. However, due to climatic change and vegetation cover decreasing, soil salinization is getting serious and expanding widely in urban areas. Especially in China that is the most populated country in the world, while it´s cultivated land area could not match with the population; thus in some regions saline land is gradually transformed to urban areas with urbanization progress, which accordingly created some environmental problems. Owing to the natural characteristics of trees, forestation is not only one way for saline-alkali soil utilization, but also can improve soil property, prevent land salinization and maintain ecological balance in urban areas. Therefore in the viewpoint of biological amelioration of salt-affected soil, planting trees is necessary and significant in urban areas for constructing an ecological city. After trees are established in the land, the watertable could be declined through increasing discharge and decreasing recharge. Additionally total salt content could be decreased, especially in soil surface profile and topsoil as well as soil physical & chemical state could be ameliorated.