Abstract
Introduction: A major challenge in seed-based restoration is ensuring that seeds germinate and develop into persistent individuals. Few studies have addressed seed-based restoration in degraded grasslands of the Pampa Austral, Argentina. Objectives: This study evaluated field establishment of four native perennial forage grasses (Nassella longiglumis, N. neesiana, N. tenuis, and Piptochaetium napostaense) sown at different densities and compared them with one exotic commercial grass, Thinopyrum ponticum. Methods: Seeds were sown in furrows in 1 m × 2 m plots in March 2023. Three sowing densities (200, 350, and 500 germinable seeds/m2) were tested in a completely randomized design with five replicates for each treatment. The number of individuals per square meter and percentage of establishment were monitored during the first year, and furrow cover was measured in April and November 2024. Results: The highest numbers of germinated seedlings and establishment percentages were recorded shortly after sowing, followed by a decrease. After 1 year, N. longiglumis and N. neesiana exhibited the highest values of individuals per square meter, establishment percentage, and cover. While the number of individuals and cover percentage increased with increased sowing density, establishment percentage showed a slight decline at higher densities. Nassella longiglumis and N. neesiana outperformed the commercial species, indicating their potential suitability for restoration, including years with below-average spring rainfall. Conclusions: Native grasses can perform as well as, or even better than commercial species under local conditions. The study provides practical evidence that incorporating native species into restoration planning in the Pampa Austral is a viable strategy.