Can predation pressure explain the curious evolution of ballistic seed
dispersal?
Abstract
Ballistic seed dispersal (ballochory) involves the autonomous explosive
release of seeds from adult plants. The unconventional physical
mechanism of this strategy has understandably drawn scientific
attention. There has been a bias toward researching physiological and
physical aspects of ballistic plants, with the evolutionary ecology
being comparatively neglected. Although ballochory is represented in 23
plant families, it has never become common. This fact should invite
curiosity regarding the selective pressures that encourage its
evolution. As a stimulus to this, we collate existing evidence into an
initial hypothesis regarding ecological situations in which ballochory
would be selected in the context of costs that can explain its rarity.
We suggest that ballochory might be selected for in plants experiencing
high predation from specialised predators on and/or directly underneath
the parental canopy. Moving forward, we suggest experimental
manipulations to test this hypothesis and promote a research agenda in
the field of ballistic seed dispersal that illuminates its intriguing
evolution.