Long-term active restoration is often employed to restore degraded grasslands. The establishment of a viable soil seed bank is the key to successful restoration, as it enhances the resilience of vegetation. However, little is known of how the soil seed bank affects vegetation resilience following long-term active restoration of degraded grasslands. We determined seed abundance and species composition of the soil seed bank and soil properties and vegetation resilience of intact, degraded, and long-term (>10 years) actively restored grasslands on the Tibetan plateau (3900–4200 m a.s.l.). The plant-soil-seed bank quality index and structural equation modelling (SEM) were used to assess the effect of the soil seed bank on vegetation resilience. After long-term (>10 years) active restoration of degraded grasslands by sowing seeds of native plant species, the densities of transient and persistent seeds increased by 5%, but seed richness (number of species) decreased by 25% when compared with degraded grasslands. This occurred largely as a result of an increase in grass but decrease in forb seeds. Persistent seeds of grasses play an important role in the productivity of restored grasslands, while the density of persistent seeds serves as an indicator of the resilience of vegetation. A combination of the plant community and soil properties determined seed density. Here, we show for the first time that long-term active restoration enhances vegetation resilience of grasslands by altering the soil seed bank. A high seed density of sown Gramineae and a low seed density of forbs in the soil seed bank is a key to the successful active restoration of degraded grasslands.

长期主动恢复常被用于恢复退化的草地。建立一个可行的土壤种子库是成功恢复的关键，因为它增强了植被的恢复力。然而，人们对土壤种子库如何影响退化草地长期积极恢复后的植被恢复力知之甚少。我们确定了青藏高原（海拔 3900-4200 米）土壤种子库的种子丰度和物种组成，以及完整、退化和长期（>10 年）积极恢复的草地的土壤特性和植被恢复力。植物-土壤-种子库质量指数和结构方程模型 (SEM) 用于评估土壤种子库对植被恢复力的影响。经过长期（> 10年）通过播种本土植物种子积极恢复退化草地，与退化草地相比，短暂和持久种子密度增加5%，但种子丰富度（物种数）减少25%。这主要是由于草的增加而杂草种子的减少。草的持久性种子在恢复草地的生产力中起着重要作用，而持久性种子的密度可作为植被恢复力的指标。植物群落和土壤特性的组合决定了种子密度。在这里，我们首次表明长期主动恢复可以通过改变土壤种子库来增强草地的植被恢复力。