Soil salinization processes in small-lake Ballestera wetland ecosystem (La Lantejuela, Seville, Spain)

Abstract

Salinization processes in soils with thermo-mediterranean-semiarid conditions within a confined environment (basin closed) are studied in Natural Reserve Ballestera small-lake ecosystems (Seville, Spain). Methodologically it is carried out a geopedological catena integrated by five drilling-profiles with depths between 0.20 and 1.50 m. A total of 21 pedo-sedimentary samples have been characterized through pH, electric conductivity, carbonates contents, magnetic susceptibility and texture determinations. The results show the presence of two different phases in the geopedological evolution of the ecosystem: one of them is previous to the geomorphological constitution of the existing wetland, characterized by carbonates and salts lateral lixiviation processes (vertisolization-tirsification processes determinant of a special black color in the soil), and the second one, later and current, distinguishing processes of salt accumulation (saline brines) and surface crust formations (saltcrete) of halite and gypsum with high value of electric conductivity (salinization and hydromorphic processes).