Seed Dispersal in Anthropogenic Landscapes

摘要

Humans alter the dispersal of seeds through land-use conversion, which changes the mix of habitats through which seeds disperse, and might also alter frugivore abundance and behaviours, and through direct persecution, which further alters the abundances and behaviours of many frugivores. The conversion of formerly continuous natural vegetation cover to human uses often leaves island-like fragments of relatively natural vegetation surrounded by agricultural fields, pastures and towns. Seed dispersal within and among the remaining fragments of natural vegetation will vary with the behaviour and local abundance of seed dispersal agents (Dennis et al., 2005; Ghazoul, 2005). Seed dispersal within a fragment might not occur if the appropriate dispersal agents are absent from the fragment. Seed dispersal between fragments might not occur if the behaviours of the available seed dispersal agents preclude movements across the intervening fields, pastures and towns or, alternatively, might be commonplace if a seed dispersal agent ranges over a wide area and seeks out patches of similar natural vegetation cover.