[Effects of altitude on the reproductive characteristics of Saussurea przewalskii at the eastern margin of the Tibetan Plateau, China.]

The paper studied the effects of altitude on reproductive characteristics in 12 populations of Saussurea przewalskii at the eastern Qinhai-Tibetan Plateau, China. The results showed that the size, reproductive organ biomass, vegetative organ biomass, capitulum number, and seed number of individual plant decreased with the increasing altitude, and the capitulum mass and hundred-grain mass increased continuously. S. przewalskii could ensure its reproduction by reducing plant body size to decrease resource consumption, and increasing the allocation of limit resources to flower biomass. In order to ensure sexual reproduction, the reproductive allocation of the plants increased with increasing the altitude. There was a trade-off between capitulum number and capitulum mass, and between seed number and hundred-grain mass, which allowed the plants to maximize their fitness under stressful conditions.