CAREER: Experimental tests of competition and facilitation among migratory large herbivores from Yellowstone National Park

生态学中的一个大问题是：“谁吃什么？”生物学家需要这个问题的答案，才能知道食物网是如何构成的。这些知识使我们能够了解物种生活在哪里，它们如何行为，以及对系统的任何干扰是否会对自然为人类提供的宝贵服务产生不利影响。然而，尽管研究人员花了一个多世纪的时间来回答这个问题，但他们仍然难以确定所有的摄食联系，这些联系共同创造了世界各地生态系统的食物网。这个项目的重点是黄石国家公园的食物网，以了解野牛和其他大型哺乳动物食草动物的食物如何能够维持它们在整个生态系统中史诗般的年度迁徙。在与国家公园管理局的合作下，本科生和早期职业研究人员将跟踪五个标志性物种的迁徙，监测它们的觅食行为，并开发新型分子生物标记物，使生物学家能够在野外测量动物营养。这个职业项目整合了现实世界和课堂上的学习目标，将促进对多样化劳动力的培训，这些劳动力能够实施现代环境科学、医疗保健和流行病学中必不可少的快速诊断测试类型。研究团队将评估关于植物多样性和可用性的季节性变化如何改变五种共存的草食动物物种的饮食的相互竞争的假设：野牛、麋鹿、骡鹿、大角羊和叉角羚。结合实地观察和实验、粪便DNA元生物编码和创新的CRISPR技术用于动物营养分析，将揭示：(I)动物饲料的变化如何反馈影响植被的结构和组成；(Ii)不同的草食物种如何刺激它们自己喜欢的食用植物的生产，而不是其他草食动物喜欢的食用植物。结果将被用来对可推广的营养模型进行参数化，以确定食物网络中的竞争和促进操作。通过开发、测试和使用新的实验室方法，并结合野外生态学中一系列久经考验的实验策略，该团队旨在克服在许多研究和培训计划中精确描述营养相互作用的长期挑战。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

A big question in ecology is: “who eats what?” Biologists need answers to this question in order to know how food webs are structured. This knowledge is what enables us to understand where species live, how they behave, and whether any disturbances to the system are liable to have adverse effects on the valuable services that nature provides to people. Yet despite working to answer this question for more than a century, researchers still struggle to identify all of the feeding links that together create the food webs of ecosystems around the world. This project focuses on the food web of Yellowstone National Park in order to understand how the diets of bison and other large mammalian herbivores are able to sustain their epic annual migrations across the ecosystem. In a collaboration with the National Park Service, undergraduates and early career researchers will track the migrations of five iconic species, monitor their foraging behaviors, and develop new types of molecular biomarkers that will enable biologists to measure animal nutrition in the wild. This CAREER project integrates real-world and classroom-based learning objectives that will advance the training of a diverse workforce capable of implementing the types of rapid diagnostic tests that are essential in modern environmental science, healthcare, and epidemiology.The research team will evaluate competing hypotheses about how seasonal changes in plant diversity and availability alter the diets of five co-occurring herbivore species: bison, elk, mule deer, bighorn sheep, and pronghorn antelope. A combination of field observations and experiments, fecal DNA metabarcoding, and an innovative adaptation of CRISPR technology for the analysis of animal nutrition will reveal: (i) how variation in animal diets feeds back to influence the structure and composition of vegetation and (ii) how different herbivore species stimulate the production of their own preferred food plants compared to the food plants preferred by other herbivores. Results will be used to parameterize a generalizable nutritional model in order to identify competition and facilitation operating in the food web. By developing, testing, and employing novel laboratory methods in combination with a series of time-tested experimental strategies in field ecology, the team aims to overcome the long-standing challenge of precisely characterizing trophic interactions in many research and training programs.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.