Exotic vs. native plant dominance over 20 years of old-field succession on set-aside farmland in Argentina

摘要: Abstract Exotic plants are major constituents of species pools in modern landscapes. Managing succession for restoration degraded ecosystems thus requires an understanding novel trajectories unfolding mixed, native/exotic plant assemblages. We examined trends native and exotic abundance over 20 years old-field on set-aside farmland the Inland Pampa, Argentina. Changes cover richness were annually monitored adjacent permanent plots established different years (1978–1989). Both occurred early, mid late successional stages, exhibiting similar life-form replacement patterns, from annual forbs, through to perennial grasses. declined with plot age. Yet, four grasses remained dominant (50–70% cover), initiated later showing increased cover. While onset succession, increasing 5 12 spp/plot, they only showed transient peaks below 30% Cluster analysis 113 plot-year samples identified alternative community states which connected by a complex network interweaving dynamic pathways. Depending plot, vegetation dynamics comprised directional temporal as well nondirectional pathways, arrested dominated Our results illustrate overwhelming role their potential hinder recovery communities former agricultural land. Community novel, mixtures could be managed deliver specific ecosystem services (e.g. forage production, carbon sequestration). However, meeting conservation goals may require active measures, including removals grass seeding.