Seed fate of Castanopsis indica (Fagaceae) in a subtropical evergreen broadleaved forest

To make comparisons with ecological patterns in temperate forests, we tracked the fates of Castanopsis indica seeds from the parent tree through first-year seedling survival in a subtropical forest in Taiwan. We used 320 magnet-inserted seeds and a magnetic locator to examine the post-dispersal pattern and seed fates of Castanopsis indica in a 1 ha permanent plot. To identity potential seed predators, we set up four automatic infrared cameras and a video camera in the C. indica canopy and on the forest floor. Macaca cyclopis, Petaurista philippensis and Callosciurus erythraeus predated seed in the canopy and Niviventer coxingi was a major predator and disperser on the ground. Rodents dispersed seeds only a short distance (mean=6.8 m±4.9 SD). Most of the dispersed seeds were found within 20 m from the experimental stations where they were initially released, and the maximum dispersal distance was 21.6 m. The hoarding depth of all found seeds or seed fragments was ≦ 10 cm, and 54% of the dispersed seeds were found in the top one cm of the litter layer. Almost all of the dispersed seeds (52.8%) were finally eaten by animals, and only one tagged seed successfully established a seedling. These results provide for a clear understanding of the regeneration dynamics of the C. indica population at this study site. This study showed that the scatter-hoarding behavior of rodents in the subtropical forest is similar to those in temperate forests.