Vegetation Controls on Dryland Salinity

Abstract

AbstractIn salt‐affected soils, salt stress causes a drastic reduction of plant transpiration. The extent of this reduction is a function of vegetation salt tolerance and can result in highly species‐specific controls on soil water budget and salinization levels. Despite their crucial role in regulating the hydrology of saline soils, the effects of salt tolerance on transpiration remain mostly unexplored. Here we propose a minimalist stochastic model of primary salinization which reproduces the hitherto overlooked feedback of salinity on the soil water balance and the active role of plant salt tolerance in modulating such an effect. We show that vegetation can exert significant control on leaching occurrence and soil salinization, thus imposing a species‐specific upper limit, Cmax, to the concentration of soluble salts in the soil. Since Cmax increases with plant salt tolerance, salt‐resilient species have the potential to sustain more saline conditions in the soil, eventually creating a favorable environment for their ecological success.