The Janzen-Connell hypothesis (JC effect) has been proposed as a mechanism for explaining high tropical tree diversity via negative conspecific density dependence imposed by natural enemies. Seed masting describes the uneven investment in reproduction between years, and could be a mechanism for reducing seed predation by means of predator satiation. JC effects select for wider dispersal kernels, allowing species to escape enemies in space, while the predator-satiation model of seed masting assumes escape from predators in time. Although representing contrasting ecological dynamics, both models are predicated on similar assumptions: that tree recruitment is limited by seed mortality via natural enemies. We suggest that the individual fitness advantages of masting and JC dynamics would be better understood by considering both mechanisms together.