Effects of mast seeding and rodent abundance on seed predation and dispersal by rodents in Prunus armeniaca (Rosaceae)

Mast seeding is a very common phenomenon in plants that are dispersed by seed scatter-hoarding animals. This reproductive strategy has been explained as adaptation to satiate predators, and predator abundance affect the seed availability and the extent of satiation. We studied how mast seeding and rodent abundance co-influenced seed predation and dispersal by rodents in Prunus armeniaca (Rosaceae) in the Dongling mountain of Beijing, China. We tracked the individual seeds marked with coded tin tags. The effects of seed crop size and rodent density were examined in May, August and October of a mast year (2000) and a non-mast year (2001). The seed removal rate was slower in mast seeding year than that in non-mast seeding year. There were more scatter hoarding and less larder hoarding with farther seed dispersal distance in the mast seeding year than that in the non-mast seeding year. The seed removal rates were positively correlated to the rodent abundance when data of six seasons of 2 years were pooled. There was high proportion of buried seeds in spring for both years. These results indicate that mast seeding and/or low rodent density increases scatter hoarding and dispersal distance, and then benefit seeding regeneration under effect of predator satiation; photoperiod seems not be very important in determining scatter hoarding activities of rodent in spring in the study region.