Responses of seedling growth and survival to post-germination cotyledon removal: an investigation among seven oak species

1. Rodents regularly rely on emerged epicotyls to locate and remove cotyledons still containing valuable nutrients. However, the extent to which acorn characteristics influence tolerance to post-germination predation has received little attention. 2. Here, we investigated the impact of cotyledon removal following epicotyl emergence on seedling performance and survival of seven oak (Quercus) species. We imitated cotyledon predation at different stages of seedling establishment and development in order to detect effects on seedling height, leaf number, and tissue/component mass. 3. Seedling growth and survival were negatively affected by cotyledon loss regardless of oak species. However, these negative effects decreased as the epicotyl length at which cotyledons were removed increased. We also found that there was a threshold epicotyl length above which seedling survival and performance were relatively unaffected in white oak species compared to red oak species. 4. Following cotyledon ...1. 啮齿类动物通常依赖已伸出的上胚轴（epicotyl）定位并移除仍含有珍贵营养物质的子叶（cotyledon）。然而，橡子（acorn）特性对植物萌发后捕食耐受性的影响程度，迄今仍鲜受关注。 2. 本研究针对7种栎属（Quercus）植物，探究了上胚轴伸出后子叶移除对幼苗生长表现与存活率的影响。我们在幼苗建成与发育的不同阶段模拟子叶捕食行为，以检测其对幼苗株高、叶片数量及组织/组分质量的效应。 3. 无论栎属物种类型如何，子叶缺失均会对幼苗生长与存活率产生负面影响。但这类负面影响会随移除子叶时的上胚轴长度增加而减弱。研究还发现，与红栎类物种相比，白栎类物种存在一个临界上胚轴长度，当子叶移除时的上胚轴长度超过该临界值时，幼苗存活率与生长表现基本不受影响。 4. 在子叶……之后