Past forest use often has a long-term negative impact on the recovery of the original plant composition of semi-natural grasslands, which are known as a legacy effect. This study investigates the impact of seed dispersal limitations on the restoration of grassland plant diversity on ski slopes with past forest use, highlighting the negative legacy effect on biodiversity recovery. Focusing on ski areas, our research contrasts the vegetation on ski slopes originally created on semi-natural grasslands such as pasture (pasture slopes) and constructed by clearing secondary forests or conifer plantations (forest slopes). We examined species richness and abundance, considering seed dispersal mechanisms, grassland management history and seed source proximity. We reveal that the proximity to species-rich grassland sources and sustained management for more than 50 years are pivotal for the restoration of native grassland vegetation. Particularly, wind-dispersed species show significant recovery on slopes with a history of extensive grassland management, suggesting that both the duration of management and the proximity to seed sources are critical for overcoming the legacy effects of past forest use. Our findings emphasize the importance of considering seed dispersal dynamics and management history in the restoration and conservation of grasslands and their biodiversity, particularly in landscapes experiencing past human intervention.