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.

中文翻译：

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不同放牧压力下短花针茅的个体繁殖策略

分析放牧胁迫下的繁殖个体的生态策略是了解草原生态系统中种群适应和维持机制的关键因素。在这项研究中，短针茅针对重度放牧，中度放牧和非放牧处理，系统分析了蒙古高原沙漠草原具有不同年龄和不同性状的生殖个体的种群。结果表明，放牧降低了种群和生殖个体的密度和生物量，但并未降低生殖分支生物量的比例。放牧减少了年轻阶段个体的比例，而增加了成年阶段个体的比例。此外，放牧减少了每个生长期的枝条宽度，长度和重量。重度放牧，中度放牧和不放牧处理的种子数量最多，分别在成年期，预老化期和衰老期。放牧减弱了枝叶性状与生殖枝性状之间以及生长期与生殖枝性状之间的潜在关系，特别是在重度放牧条件下。我们的研究表明，在长期放牧的压力下，短链酵母通过牺牲一些成长期个体，改变表型和减少具有高产种子的个体的年龄来维持其生命周期，从而维持生殖个体中生殖分支的资源分配。