关键词: 小型啮齿动物, 更新, 壳斗科, 象虫, 都江堰

Abstract: Rodents, as both seed predators and seed dispersers, influence natural regeneration of nut-bearing species. Rodents' ability to discriminate insect-infested seeds was often debated. By offering seed-eating rodents three acorn types (sound acorns, weevil-infested acorns with or without weevils) of four fagaceous species (Quercus variabilis, Q. serrata, Cyclobalanopsis glauca, and Castanopsis fargesii) with different ratios in an experimental forest farmof Dujiangyan City, Sichuan Province , China , during the autumn of the year 2001. This study was carried out to test the hypothesis whether seed-eating rodents have the ability to discriminate infested seeds. The disappearance of infested acorns was slower than that of sound acorns for all species of all ratios. Rodents significantly removed more sound acorns than infested acorns of all species (67%- 92%), even when the proportion of infested acorns increased. When the ratio of infested acorns increased, the consumed and rejected proportions of infested acorns decreased while the removal rate increased. Seed-eating rodents do not always reject infested acorns , which might be related to acorn availability and quantity aswell as to rodents' foraging strategies. The results demonstrate that seed-eating rodents discriminate infested acorns accurately , and differentially remove and cache most of sound acorns and consume infested acorns (including weevils). This may affect the fates of sound and infested acorns and then influence natural regeneration of these nut-bearing species.

Key words: Small rodents, Regeneration, Fagaceae, Weevils, Dujiangyan