Disentangling water sources in a gypsum plant community. Gypsum crystallization water is a key source of water for shallow-rooted plants.

Plants coexisting in gypsum communities segregate their hydrological niches according to their rooting depth. Crystallization water of gypsum represents an unaccounted, vital source for most of the shallow-rooted species growing on gypsum drylands. Thus, crystallization water helps shallow rooted species to endure arid conditions, which eventually accounts for the maintenance of high biodiversity in these specialized ecosystems.