Effects of increased precipitation and on the life history of spring- and autumn-germinated plants of the annual Hypecoum erectum L.

Precipitation change is one of the research hotspots in global climate change nowadays and a major environmental factor affecting plant growth and development. In this study, we mainly analyzed the life-history traits of spring-and autumn-germinated seeds of H. erectum L. By conducting a field control experiment with three precipitation regimes (natural precipitation, 30% water addition, and 50% water addition), we comparatively investigated the phenology, seedling survival rate, plant size, seed yield, and biomass accumulation and allocation of SG and AG plants. The results showed that increased precipitation delayed the phenology of both SG and AG plants, and significantly improved seedling survival rate, with the survival rate of AG plants being remarkably lower than that of SG conspecifics. In addition, increased precipitation significantly increased the leaf number, branch number, branch length and plant height of SG plants, whereas it remarkably decreased the leaf number and root length of AG plants. After water addition, the seed production of both SG and AG plants increased significantly, with the seed yield of AG plants being remarkably higher than that of SG ones. With the increase in precipitation, the proportion of dormant seeds of SG plants increased significantly, whereas the corresponding proportion of AG plants decreased remarkably. The effects of increased precipitation on the life history of H. erectum L. varied with germination seasons, which is of great significance for predicting its population dynamics under climate change.