Edaphic characterization and plant zonation in the Qaidam Basin, Tibetan Plateau

This paper presents a study of edaphic characteristics and their relationship with plant distribution in the Qaidam Basin, Tibetan Plateau, and establishes a distribution model for plants in sandy gravel Gobi to dry salt lake areas. All of the communities in the study area were dominated by plants with strong saline-alkaline tolerance. In this area, salts appeared to migrate to the surface; the surface soil was striped, and the salt distribution varied from sandy gravel Gobi to dry salt lake areas. The salt composition mainly consisted of NaCl in the surface crust. In the subsurface layers, the salt composition was dominated by Ca²⁺, Cl^- and SO₄^2-. The type of vegetation at the study site can be divided into two categories: salt-tolerant vegetation and weakly salt-tolerant vegetation. The salt-tolerant vegetation is influenced by Na⁺, Cl^-, and the salinity. The soil of these vegetation communities had a higher salt and Na⁺ concentration and a lower Ca²⁺ and K⁺ concentration. The weakly salt-tolerant vegetation is mainly affected by the Ca²⁺/Na⁺ and K⁺/Na⁺ ratios. Based on the above results, a vegetation distribution model for saline lakes on the inland plateau was established.