Is bi-seasonal germination an optimal choice for an ephemeral plant living in a cold desert?

Research on germination strategies has been proposed as a tool for understanding the evolutionary patterns of plant species living in extreme climate conditions. Previous research has concentrated on spring-germinated plants, while there has been little investigation on the ecological significance of ephemeral plants that germinate in both autumn and spring. The biological characteristics and life history strategies of autumn- and spring-germinated plants of Hypecoum erectum L. that belongs to Hypecoum in Papaveraceae family in the southern part of the Gurbantunggut Desert, China, were investigated from 2016 to 2017. Results showed that: (1) the interval from seedling emergence to the end of the life cycle in autumn-germinated plants (202–208 d) was significantly longer than that in spring-germinated plants (53–65 d); (2) the height, crown, principal axis and the number of leaves of autumn-germinated plants were much greater than those of spring-germinated plants; (3) allocation of dry mass to reproduction was 30.24% (±2.41%) and 10.12% (±0.68%) in autumn- and spring-germinated plants, respectively. Autumn-germinated seedlings of H. erectum had an advantage in avoiding the competition between annual and perennial herbs that had longer periods of vegetative growth. Spring-germinated seedlings need to ensure the survival of population when only a fewer autumn-germinated seedlings successfully overwinter. In an unpredictable environment, the germination strategy of bet hedging not only utilizes the resources and reduces the competition intensity in offspring, but also ensures the survival of the plant population.