Abstract:Aims Ephemerals are important in desert ecosystems, playing a key role in ecosystem stabilization. Previous research has concentrated on spring ephemerals. Little is known about biological and ecological characteristics of ephemerals that germinate in spring and autumn and about the significance of autumn ephemerals in stabilizing desert ecosystems. Methods We marked plants of Plantago minuta and Erodium oxyrrhynchum, species that germinate in spring and autumn. We investigated their crowns, leaves and phenological characteristics in the field during their growing seasons and measured their dry weights and mean arbuscular mycorrhizal colonization rates in the lab oratory. Important findings Leaves, flowers, fruits, seeds and dry weights of autumn plants are larger than those of spring plants. For example, in autumn P. minuta and E. oxyrrhynchum produced 13.0 and 4.4 times as many seeds and flowered 14 and 7 days earlier, respectively, than spring plants. In addition, mean arbuscular mycorrhizal colonization rates were higher in autumn than spring plants, accelerating the absorption of phosphorus. Autumn plants had greater capability of reproduction and ecosystem stabilization, allowing them to play an important role in stabilizing the desert ecosystem.