Abstract In addition to causing loss of biodiversity, habitat fragmentation can alter species interactions. Relative to well‐studied effects of fragmentation on mutualistic interactions like pollination, effects on antagonistic interactions remain poorly understood. One such interaction, seed predation, may be particularly important because it can alter plant demographics and trigger cascading changes to both plant and seed predator communities. Previous studies have failed to find consistent effects of fragmentation on seed predation, possibly because seed predation occurs at two distinct stages relative to seed dispersal (pre‐ and post‐dispersal). Working within a large‐scale fragmentation experiment, we tested effects of three consequences of fragmentation—edge‐to‐area ratio, distance to edge, and connectivity (via habitat corridors)—for pre‐dispersal seed predation and post‐dispersal seed removal of eight plant species of conservation interest. We found that fragmentation effects, especially distance to edge, were more likely significant for post‐dispersal seed removal (assumed to positively correlate with seed predation) than for pre‐dispersal seed predation, although the significant patterns differed across species. Post‐dispersal seed predation declined sharply with seed mass, and this decline was greater at the patch edge. This led to larger seeded species having less predation nearest to the edge compared to patch interiors. This experiment highlights how fragmentation can alter seed predation by generating edge effects and how species traits can predict consequences across a community.
Smith et al. (Fri,) studied this question.