Abstract

Soil degradation, most notably caused by salinization and water-logging, creates formidable problems in arid and semi-arid environments. Advancing our knowledge of salt-affected soils is a prerequisite for understanding how salinization affects environmental concerns, such as soil erosion, nutrient leaching, and lack of vegetation cover. Therefore this study investigated the impact of salt diapirs on soil physicochemical conditions, as well as explored the relationship between halophytic vegetation and soil factors, and described the composition and distribution of plant species in relationship to soil salinity. The study area was divided into three units based on different geomorphologic conditions, slopes and vegetation type.Changes in salinity, soil properties and vegetation were studied. Results showed that the proportion of clay increased while silt and sand decreased with increasing distance from salt diapirs. The presence and kind of ions in all samples consistently indicated high levels of Na, and moderate levels of Mg, Ca, and K. Based on the soil conditions, plant covers were changed to types with more resistance to salinity and water-logging. Typically, this results in a decrease in soil structure stability through degradation of soil aggregates and a variation in the composition of the vegetation toward undesirable species.

Key words: Salt diapirs, salinization, soil physicochemical properties, vegetation pattern, arid environment.