Lai Xin, Guo Cong, Xiao Zhishu
Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, College of Life Science, Sichuan University, Chengdu, China; State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
Integr Zool. 2014 Jun;9(3):246-54. doi: 10.1111/1749-4877.12046.
By tracking the fate of individual seeds from 6 frugivore-dispersed plants with contrasting seed traits in a fragmented subtropical forest in Southwest China, we explored how rodent seed predation and hoarding were influenced by seed traits such as seed size, seed coat hardness and seed profitability. Post-dispersal seed fates varied significantly among the 6 seed species and 3 patterns were witnessed: large-seeded species with a hard seed coat (i.e. Choerospoadias axillaries and Diospyros kaki var. silvestris) had more seeds removed, cached and then surviving at caches, and they also had fewer seeds predated but a higher proportion of seeds surviving at the source; medium-sized species with higher profitability and thinner seed coat (i.e. Phoebe zhennan and Padus braohypoda) were first harvested and had the lowest probability of seeds surviving either at the source or at caches due to higher predation before or after removal; and small-seeded species with lower profitability (i.e. Elaeocarpus japonicas and Cornus controversa) had the highest probability of seeds surviving at the source but the lowest probability of seeds surviving at caches due to lower predation at the source and lower hoarding at caches. Our study indicates that patterns of seed predation, dispersal and survival among frugivore-dispersed plants are highly determined by seed traits such as seed size, seed defense and seed profitability due to selective predation and hoarding by seed-eating rodents. Therefore, trait-mediated seed predation, dispersal and survival via seed-eating rodents can largely affect population and community dynamics of frugivore-dispersed plants in fragmented forests.
通过追踪中国西南部一片碎片化亚热带森林中6种由食果动物传播种子的植物的单个种子的去向，这些植物的种子具有不同特征，我们探究了啮齿动物的种子捕食和贮藏行为是如何受到种子大小、种皮硬度和种子收益性等种子特征影响的。种子传播后的命运在这6种种间差异显著，呈现出3种模式：种皮坚硬的大种子物种（即腋花泡花树和野生山柿）有更多种子被移除、贮藏，且贮藏后存活下来，同时它们被捕食的种子较少，但在种子源处存活的种子比例较高；收益性较高且种皮薄的中等大小种子物种（即滇楠和短柄稠李）最先被收获，由于在移除前后被捕食率较高，其种子在种子源处或贮藏点存活的概率最低；收益性较低的小种子物种（即日本杜英和灯台树）种子在种子源处存活的概率最高，但在贮藏点存活的概率最低，这是因为在种子源处被捕食较少，在贮藏点的贮藏量较低。我们的研究表明，由于食种子啮齿动物的选择性捕食和贮藏行为，食果动物传播种子的植物的种子捕食、传播和存活模式很大程度上由种子大小、种子防御和种子收益性等种子特征决定。因此，通过食种子啮齿动物介导的种子捕食、传播和存活特征能够在很大程度上影响碎片化森林中食果动物传播种子的植物的种群和群落动态。
