Individual reproductive strategy of Stipa breviflora under different grazing pressures

Analyzing the ecological strategies of reproductive individuals under grazing stress is a key factor in understanding the adaptation and maintenance mechanisms of populations in grassland ecosystems. In this study, a Stipa breviflora population with reproductive individuals of different ages and individual traits in the desert steppe of the Mongolian Plateau was systematically analyzed in response to heavy grazing, moderate grazing and non‐grazing treatments. The results showed that grazing reduced the density and biomass of the population and reproductive individuals but did not reduce the proportion of reproductive branch biomass. Grazing reduced the proportion of individuals in the young stage and increased the proportion in the adult stage. In addition, grazing reduced the width, length and weight of the foliage branches at each growth stage. The largest numbers of seeds in the heavy grazing, moderate grazing and non‐grazing treatments were in the adult stage, the pre‐aging stage and the aging stage, respectively. Grazing weakened the potential relationships between foliage branch traits and reproductive branch traits and between growth stage and reproductive branch traits, especially under heavy grazing. Our study suggested that under long‐term grazing stress, S. breviflora completed its life cycle by sacrificing some of the growth stage individuals, changing phenotypes and reducing the age of individuals with high‐yielding seeds to maintain resource allocation to reproductive branches in reproductive individuals.