DISSERTATION RESEARCH: The Importance of Plant Ontogeny for Tri-trophic Interactions

食草动物的伤害是植物种群死亡的最大来源之一。因此，植物进化出了一系列广泛的防御措施来保护自己不被吃掉。然而，植物防御的生产是昂贵的。植物在整个植物发育（即个体发育）过程中如何将资源分配给各种基本功能（包括防御）受到限制。虽然最近的研究表明，植物个体发育可以影响许多与食草动物相关的性状的表达，如营养成分和物理和化学防御，但很少有人关注这种变化对消费物种的潜在间接影响。该项目的目的是评估植物性状的变化，如营养价值、大小、化学和物理防御，在寄主植物（车前草）的整个个体发育过程中，如何改变其与专业食草动物（七叶蝶，Junonia coenia）及其捕食者的相互作用。研究人员将进行三次温室和野外实验，研究蝴蝶选择在哪里产卵、毛毛虫的表现和毛毛虫在四个寄主植物发育阶段被捕食的风险。本研究将记录植物性状的时间变化对植物-草食-捕食动态的潜在生态和进化后果。这些知识对农业系统和保护生物学都很重要。能够预测不同寄主植物发育阶段的食草寄主选择、性能和捕食风险，将有助于改进作物病虫害管理策略，以及制定更好的入侵植物物种根除计划。在这项研究中，几名本科生将接受生态学研究方法的培训，研究人员将通过与科罗拉多大学教育项目建立的关系，向K-12学生和教师进行公共宣传。

Herbivore damage is one of the greatest sources of mortality in plant populations. As a consequence, plants have evolved a wide array of defenses to protect themselves from being eaten. However, the production of plant defenses is costly. Plants are constrained in how they can allocate their resources throughout plant development (i.e. ontogeny) to various essential functions, including defense. While recent studies have demonstrated that plant ontogeny can affect the expression of numerous traits relevant to herbivores, such as nutritional content and physical and chemical defenses, less attention has been given to investigating potential indirect effects of this variation on consumer species. The aim of this project is to assess how variation in plant traits, such as nutritional value, size, and chemical and physical defenses, throughout the ontogeny of a host-plant (Plantago lanceolata), can modify its interactions with a specialist herbivore (Buckeye butterfly, Junonia coenia) and predators of that herbivore. The investigators will conduct three greenhouse and field experiments examining where butterflies choose to lay their eggs, caterpillar performance and caterpillar predation risk at four host plant developmental stages. This research will document potential ecological and evolutionary consequences of temporal variation in plant traits on plant-herbivore-predator dynamics. This knowledge is important for both agricultural systems and conservation biology. Being able to predict herbivore host selection, performance, and predation risk on different host plant developmental stages will help to improve pest management strategies for crops, as well as to develop better eradication plans for invasive plant species. Several undergraduates will be trained in ecological research methods in this study, and the researchers will conduct public outreach to K-12 students and teachers through established relationships with University of Colorado educational programs.