Re-caching behaviour of rodents improves seed dispersal effectiveness: Evidence from seedling establishment

Abstract

Long-distance seed dispersal is disproportionately important for recruitment, range expansion and gene flow in plant populations. The re-caching of seeds by rodents is considered a mechanism of long-distance seed dispersal. The effect of re-caching on dispersal distance is well studied. However, how re-caching by rodents affects seedling establishment remains unclear. To assess the role of re-caching by rodents on seedling establishment, we tracked a large number of seeds and investigated the seed dispersal and seedling establishment of two large-seeded tree species (Scleropyrum wallichianum and Garcinia xanthochymus) in a tropical forest. We found that rodents scatter hoarded 48.9–71.3% of the released seeds, and a total of 23.8–36.6% of the initial caches of both species experienced re-caching up to 2 or 3 times. Re-caching was correlated with farther dispersal and a higher probability of seedling establishment for both species. In addition, re-caching contributed to medium and long-distance seed dispersal, with 17.2% and 18.5% of seedlings located >50 m from parent trees for G. xanthochymus and S. wallichianum, respectively, and 3.4% of seedlings of G. xanthochymus located >100 m from parent trees. Our results suggested that re-caching by rodents can promote seed dispersal effectiveness and contribute to effective long-distance seed dispersal.