Seed morphological traits and seed element concentrations of an endangered tree species displayed contrasting responses to waterlogging induced by extreme precipitation

Understanding how plant species respond to extreme climate events is crucial for planning management and conservation actions. As extreme precipitation accelerates, the waterlogging related to it is predicted to be more severe and frequent. To date, however, empirical studies addressing the effects of extreme precipitation-induced waterlogging on the seeds of wild plants are still scarce. In this study, we compared the size, mass and element concentration of seeds produced by non-inundated and inundated individuals of Sinojackia huangmeiensis, a critically endangered tree species with only one extant wild population. Compared to the seeds from non-inundated individuals, the seed length, seed width, and seed mass were all smaller for seeds from inundated individuals. However, the concentrations of four chemical elements in the seed displayed an opposite trend, except those elements (e.g., C, K, Ca, Mg, Al, Fe, Ni, B, Mo, and Cu) with no significant difference. Some toxic elements (e.g., Mn) accumulated in the seeds from inundated individuals, as well as some nucleic acid-protein elements (e.g., N and P) and enzymatic (e.g., Zn) elements. Our study provides rare empirical evidence that wild plants could respond to extreme precipitation-induced waterlogging by changing both seed morphological traits and element concentrations.