Soil-Plant Relationships in the Sabkhat of America

Abstract

In Sabkhat, plant ecology will depend on the soil characteristics, according to the type and dynamics of sediments and to water movement, dynamized by salt concentration and climate. Soil profile defines the ability of species to develop under its influence, according to critical variables such as soil salinity, water table depth and granulometry. Also, plant growth and development will depend on special physiological and morphological characteristics that are suited to extreme conditions in sabkhat. In America, sabkhat are the habitat of halophytic species, dwelling characteristic genera that can be found from the Columbia Basin to the Monte ecoregion. In this review soil conditions, plant characteristics and their interactions in saline basins of America will be discussed. Hydrology controls the sediment and solute chemistry, forming a dynamic cycle with halophyte vegetation. When the water table is depressed, deflation is enabled and medium-coarse particles are deposited over small hummocks, usually by the form of dunes or over tussocks, forming nabkhat. Aeolian dust may be responsible for the development and maintenance of plant communities along a salinity gradient towards the adjacent dunes in the periphery. Sabkhat hold an important pool of plant functional groups according mainly to soil salinity and water table depth. Such functional groups perform important ecological functions in the soil-plant-climate triad, such as soil formation, facilitation and zonation. These processes have a dynamic behaviour according to seasonality and climate interannual and decadal variability, assisted by anthropic impacts such as fire, overgrazing or even climatic change.