Frugivory and seed dispersal revisited: Codifying the plant-centred net benefit of animal-mediated interactions

Abstract

Many plants rely on fruit consuming animals (frugivores) to disperse their seed. Successful dispersal is influenced inter alia by quantity of seeds dispersed, dispersal distance, nature of seed deposition and post-depositional seed predation. The germination potential of the seed is commonly enhanced through physical or chemical scarification while the ingested fruit is processed in the gastrointestinal tract. Most discussions of animal-mediated seed dispersal are vector-centric and explore in depth the minutiae or the consumption by species or examine mutualistic networks. This paper provides a framework that conceptualises the effect of animal-mediated seed dispersal in terms of net benefits to the plant. These benefits, viewed in terms of a dispersed plant’s presence in the landscape, are codified as suisubstitution (new term), intensification, expansion, and colonisation. Only vectors with an ability to traverse and utilise multiple ecological landscapes provide true net colonisation benefits to a plant species. This is particularly essential in this later period of the Anthropocene where ecological landscapes have become increasingly fragmented and are being augmented or replaced by novel ecosystems.