Dispersal

Abstract

Successful regeneration by a plant depends upon its seeds being dispersed to situations where they can germinate and establish seedlings. Places where such conditions are met have been called‘safe sites’ (Harper, 1977). Each species has its own characteristic requirements in this respect, so that a safe site for one species may be unsafe for another. The different patterns of dispersal found in plants are presumably the result of natural selection for features which increase the chances of the seeds being favourably placed. This does not necessarily involve maximizing the distance over which the seeds travel, as suitable safe sites might be more readily available in the vicinity of the parent plant than further away, as is often the case with desert plants (Ellner and Shmida 1981).