Moderate Seasonal Grazing During the Seed‐Set Stage Is Detrimental to Seed Rain and the Soil Seed Bank in an Alpine Meadow

Aims Seed rain and the soil seed bank are essential resources for the reproduction and regeneration of grassland vegetation. However, the effects of seasonal rotational grazing—the most common type of grassland management/utilization worldwide—on the regulatory mechanisms of the structure and composition of seed rain and soil seed banks and their relationship with aboveground vegetation are still unclear. Location We conducted a 3‐year (2020–2022) study of yak seasonal rotational grazing in an alpine meadow on the northeastern Qinghai‐Tibetan Plateau. Methods We investigated the characteristics of temporal (different years) and spatial (different seasonal pastures) variations in species richness and density of the aboveground vegetation, seed rain, and transient soil seed bank. The similarities between seed rain and soil seed bank and aboveground vegetation composition were also compared. Results We found that seasonal rotational grazing significantly impacted the renewal of the aboveground vegetation, seed rain, and the density of the soil seed bank of the alpine meadow. During the warm season (seed‐setting period, mid‐June to late July), livestock grazing reduced both the richness and density of seed rain species and interrupted its supplementation of the soil seed bank and thus was detrimental to seed reproduction and renewal of alpine‐meadow plants. Within the warm‐season paddocks, prolongation of the grazing utilization time gradually decreased the density of the upper‐layer (0–5 cm) transient seed bank, whereas the density of aboveground vegetation gradually increased. Moreover, grazing led to significant differentiation between the composition of aboveground vegetation and seed rain/soil seed bank, resulting in low similarity between those three categories. Conclusions Warm‐season grazing is a potential driving force for the shift in aboveground vegetation reproduction mode from sexual (i.e., seeds) to vegetative in alpine meadows. We recommend excluding grazing during the seed‐set stage, allowing grazing during the seed maturation period (mid‐August to late September), and implementing appropriate rotational grazing among seasonal paddocks as part of an effective management strategy for alpine meadows on the Qinghai‐Tibetan Plateau.