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，以了解食物网是如何构成的。这种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大自然为人类提供的宝贵服务产生不利影响。然而，尽管世纪来一直在努力回答这个问题，研究人员仍然难以确定共同创造世界各地生态系统食物网的所有喂养环节。该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饮食是如何能够维持其史诗般的年度迁移整个生态系统。在与国家公园管理局的合作中，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，并开发新型的分子生物标志物，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学习目标，将促进培训能够实施现代环境科学，医疗保健和流行病学所必需的快速诊断测试类型的多元化劳动力。研究团队将评估植物多样性和可用性的季节性变化如何改变五种共存食草动物的饮食的相互竞争的假设：野牛、麋鹿、骡鹿、大角羊和叉角羚羊。结合实地观察和实验，粪便DNA元条形码，以及CRISPR技术在动物营养分析中的创新应用，将揭示：（i）动物饮食的变化如何反馈影响植被的结构和组成，以及（ii）与其他食草动物偏好的食用植物相比，不同的食草动物物种如何刺激自己偏好的食用植物的生产。结果将被用来参数化的一个概括的营养模型，以确定竞争和促进运作的食物网。通过开发、测试和采用新颖的实验室方法，并结合一系列经过时间考验的野外生态学实验策略，该团队旨在克服长期存在的挑战，即在许多研究和培训项目中精确描述营养相互作用。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

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.