Seasonal variations of wild apricot seed dispersal and hoarding by rodents in rehabilitated land

Rodents feed with and disperse plant seeds, which may thereby affect the seed spatio temporal distribution, germination, and seedling establishment, and eventually play an important role in the restoration of deforested area. Taking the State-owned Yugong Forest Farm in Jiyuan of Henan, China as study site, the tagged seeds of wild apricot (Prunus armeniaca) were artificially released in rehabilitated land in the spring, summer, and autumn 2008, aimed to investigate their dispersal and hoarding by rodents in different seasons. It was found that Apodemus peninsulae, Niviventer confucianus, and Apodemus agrarius were the main rodent species acting on the seed dispersal and hoarding. The dispersal rate of the seeds was significantly lower in spring than in summer, and also, lower in summer than in autumn. The amount of removed seeds was affected by the interaction of season and seed status, being significantly lesser in spring than in summer, and lesser in summer than in autumn. The mean transportation distance differed with seasons, which was longer in au tumn than in spring and summer. The cache size in majority caches was 1 seed, but in a few caches, each cache contained 2 or 3 seeds. The cache number was affected by the interaction of season and seed status, i.e., one seed cache was lesser in spring than in summer and autumn, while the caches containing 2 or 3 seeds were more in summer and autumn. Among the 1800 seeds released, there were five seeds hoarded in summer and autumn respectively established seedlings in the next year of the experiment.