中文摘要：

有性生殖（实生更新）和无性生殖（萌生更新）是植物繁殖的两种关键方式。自然界中,个别物种同时具备两种更新方式,米心水青冈（Fagus engleriana Seem.）就是典型的物种。已有研究表明萌生更新在米心水青冈种群生活史中普遍存在,可使其占据原有生态位（生态位占据假说）,但对米心水青冈实生更新的研究却未见报道。为了探索啮齿动物对米心水青冈实生更新的作用机制,笔者在神农架米心水青冈林中通过坚果摆放实验,研究啮齿动物对米心水青冈坚果传播机制的影响。结果显示,鼠类对坚果的原地捕食率高达81.22%;坚果被扩散率低,仅18.56%;坚果在原地平均留存时间为（5.25±5.95）d;坚果扩散距离为（2.63±1.60）m。研究发现,米心水青冈坚果被啮齿动物捕食率极高,贮藏率极低,且坚果被传播距离在同属植物中较小,不利于该物种更新繁殖。萌生更新在很大程度上弥补了米心水青冈实生更新繁殖方式的不足。本研究结果有助于对水青冈属植物繁殖策略的理解。

英文摘要：

Sexual reproduction（seedling regeneration） and asexual reproduction（sprouting regeneration） are two primary methods of plant propagation. Many plant species can exhibit both methods simultaneously,including Fagus engleriana Seem. Several studies have found that sprouting regeneration is pervasive in the life history of F. engleriana,and can facilitate the initial occupation of an ecological niche（ecological niche occupied hypothesis）; however,very little is known about the seedling regeneration of F. engleriana. To explore the role of rodents in the dispersal of F. engleriana nuts,we conducted a nut placement trial in F.engleriana beech forests in the Shennongjia area of China. Results showed that the nut predation rate by rodents was high,up to 81. 22%,but only 18. 56% of nuts were removed.Mean retention time and dispersal distances of the nuts were（5. 25 ± 5. 95） d and（2. 63 ±1. 60） m,respectively. Our results indicated that the nut predation and cache rates by rodentswere extremely high and slow,respectively. The dispersal distances of F. engleriana nuts were shorter than that of other Fagus species. These findings indicate that rodents do not efficiently facilitate F. engleriana nut dispersal. Thus, sprouting seedlings could be a vital way to enhance the regeneration of F. engleriana. This study enhances our understanding of the broad paradigm of plant propagation evolution,with particular regard to the reproductive strategies of the genus Fagus.