When anthropogenic-related disturbances overwhelm demographic persistence mechanisms

1. Population decline is associated with increased vulnerability to extinction, but also with possible density-, frequency-, or distance-related ‘rarity advantages’ that increase recruitment success as individuals become isolated from their congeners. Distinguishing between these alternatives (risk versus recovery of rare populations via demographic processes) has become critical, given how anthropogenic disturbances are causing population declines globally. 2. Here, we demonstrate how distance-related rarity advantages are evident in spatially isolated recruits of a canopy-dominant but regionally rare species of oak that appears to be suffering recruitment collapse. As distance from parent trees increased, seedlings had significantly more leaves and experienced reduced insect browsing and intraspecific competition. Long-term field-based experimental treatments revealed these advantages to be associated with rapid rates of juvenile maturation and survival that are unobserved in natural ...