Attributes of propagules that aid dispersal

Abstract This chapter discusses traits that determine dispersal of propagules by different vectors. It pays special attention to dispersal by air, water, animals, and humans, since these vectors have received the greatest attention in scientific literature. It is clear from morphological and chemical traits that many species have evolved an enhanced ability to be dispersed by particular vectors. However, propagules may be moved by a number of vectors, both physical and biological. There is variation in these traits between species, between and within populations, and among propagules on the same plant. Mass, volume, and area determine the propensity of any propagule to be moved in air and water. Dispersal on the outside of animals is correlated with propagule shape, mass, and adhesive ability, while size relative to the mouth of the animal and chemical constituents determine which species will be ingested and how long they might be carried.