• Masting is a widespread reproductive strategy in plants that helps to reduce seed predation and increase pollination. However, masting can involve costs, notably negative density-dependent (NDD) seedling survival caused by concentrating reproduction in intermittent events. Masting benefits have received widespread attention, but the costs are understudied, which precludes understanding why some plant species have evolved intense masting, while others reproduce regularly.
• We followed seed production, seed predation (both 13 yr), and seedling recruitment and survival (11 yr) in Sorbus aucuparia. We tested whether NDD in seedling survival after mast years can reduce the benefits of pulsed reproduction that come through predator satiation.
• Seed predation rates were extreme in our population (mean = 75%), but were reduced by masting. The commonly accepted, but untested, assertion that pulsed recruitment is associated with strong NDD was unsupported. Consequently, the proportion of seedlings that survived their first year increased with fruit production. This provides a rare test of economies of scale beyond the seed stage.
• Our results provide estimation of the costs of mast seeding, and indicate that these may be lower than expected. Low masting costs, if common, may help explain why masting is such a widespread reproductive strategy throughout the plant kingdom.

中文翻译：

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肥大的成本和收益：Sorbus aucuparia 幼苗存活的负密度依赖性不会降低规模经济

• Masting 是一种在植物中广泛使用的繁殖策略，有助于减少种子捕食和增加授粉。然而，肥大可能涉及成本，特别是在间歇性事件中集中繁殖导致的负密度依赖 (NDD) 幼苗存活率。肥大的好处已受到广泛关注，但成本研究不足，这使人们无法理解为什么一些植物物种进化出强烈的肥大，而另一些则定期繁殖。
• 我们跟踪了Sorbus aucuparia的种子生产、种子捕食（均为 13 年）和幼苗补充和存活（11 年）。我们测试了 NDD 在肥大年后的幼苗存活中是否可以减少通过捕食者饱食带来的脉冲繁殖的好处。
• 在我们的种群中，种子捕食率非常高（平均值 = 75%），但通过放牧降低了。普遍接受但未经检验的关于脉冲招募与强 NDD 相关的断言没有得到支持。因此，第一年存活的幼苗比例随着果实产量的增加而增加。这为超越种子阶段的规模经济提供了难得的考验。
• 我们的结果提供了对桅杆播种成本的估计，并表明这些成本可能低于预期。低肥大成本，如果常见的话，可能有助于解释为什么肥大是整个植物界如此广泛的繁殖策略。