Abstract

In the early to mid-20th century, southern beech forests (Nothofagus pumilio) in northern Chilean Patagonia were burned and converted into grasslands for livestock, promoting the spread of non-native species. These exotics now coexist with native flora, but their long-term effects on biodiversity remain unclear. Grazing exclusion has been proposed as a strategy to reduce exotics and improve conditions for southern beech regeneration. The aim of this study was to evaluate the long-term effects of livestock abandonment on grassland diversity and tree regeneration. We assessed the herbaceous species and functional composition in forests and adjacent grasslands along 80 × 10 m transects, comparing treatments with and without cattle grazing. Surveys were conducted one, two, six and nine years after the exclusion of grazing. Changes over time and along the transect in floristic and functional composition were analyzed through Principal Components Analysis (PCA). Results showed that the exclusion increased the number and relative abundance of native species in both open grasslands and forest understories within one to six years. In contrast, exotics species increased under grazing pressure but declined steadily following exclusion, with stronger reductions observed in forests, indicating greater resilience of forest systems compared to grasslands. Although grazing limited tree seedling establishment, its cessation alone did not ensure forest regeneration. Seedlings remained scarce, likely due to soil degradation, light competition, and small herbivores. These findings provide insights for biodiversity conservation and restoration in temperate silvopastoral landscapes.