EAGER: Comparison of Amino-Acid and Bulk-Tissue Stable Isotope Techniques for Analyzing Modern and Historical Food Webs

食物网结构反映了物种丰富度和功能多样性，是生态系统健康状况的重要指标。最近尝试使用化合物特异性稳定同位素而不是体组织技术来评估食物网，有望提高对食物网动态和营养相互作用的理解。这些依赖于氨基酸同位素分析的新方法需要经过实验验证，然后才能将这一有希望的进展应用于天然食物网。本研究以实验室多层次食物链实验为基础，比较了新型氨基酸技术和常规大组织方法的生态敏感性和成本效益。研究人员将在实验室中创建一个真实的四级食物链，允许消费者将猎物的同位素特征整合到他们的组织中。在实验结束时，将分析氨基酸和大块组织的稳定同位素，以确定氨基酸是否比大块组织的方法更准确地测量营养位置。这个项目更广泛的影响主要在于提出了一种评估天然食物网的新方法。如果成功，该方法最终可以应用于陆地和水生群落，并将推进食物网生态学的一般领域。它也可以应用于博物馆标本，使研究人员能够检查历史和当代的食物网。

Food web structure is an important indicator of ecosystem health because it reflects both species richness and functional diversity. Recent attempts to use compound-specific stable isotopes rather than bulk-tissue techniques to evaluate food webs promise to improve understanding of food web dynamics and trophic interactions. These new methods, which rely on amino acid isotope analyses, need to be validated experimentally before this promising advance can be applied to natural food webs. This study relies on a laboratory multi-level food chain experiment to compare the ecological sensitivity and the costs and benefits of new amino acid techniques and common bulk-tissue methods. The researchers will create a realistic, four-level food chain in the laboratory that allows consumers to integrate prey isotopic signatures into their tissues. At the end of the experiment, both amino acid and bulk tissue stable isotopes will be analyzed to determine whether amino acids provide a more accurate measure of trophic position than bulk tissue methods.The broader impacts of this project lie primarily in advancing a new method for evaluating natural food webs. If successful, the method could eventually be applied to terrestrial and aquatic communities, and would advance the general field of food web ecology. It also could be applied to museum specimens, allowing researchers to examine historical as well as contemporary food webs.