Abstract
Seedling emergence and survival were followed in undisturbed vegetation and in the center and edge of experimental gaps in two midsuccessional old-field communities. The gaps were designed to simulate the effects of burrowing mammals. Emergence of most species and of all species combined was significantly higher in gaps than in undisturbed vegetation. Survival also tended to be higher in gaps, but was variable among replicates and rarely was significantly different between gaps and undisturbed vegetation. Ability to emerge or survive in undisturbed vegetation relative to gaps was not strongly related to mean seed mass of the species.