Novel geochemical methods for assessing trophic ecology in modern and ancient ecosystems

评估现代和古代生态系统营养生态的新地球化学方法

• 批准号: RGPIN-2021-02572
• 负责人: Chritz, Kendra
• 金额: $ 2.04万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=742084
• 关键词: Novel; geochemical; methods; assessing; trophic

Trophic (consumer-prey) dynamics are the essential building blocks of ecosystems. These interactions drive ecosystem functionality and biogeochemical cycles globally, and are sensitive to the impacts of climate change and human activity in the past and present. Geochemical (isotopic) proxies for diet and trophic interactions are critical tools for tracing these dynamics without direct observation and are essential for a range of fields from conservation to paleosciences. In simple trophic systems, traditional stable isotopes such as carbon (d13C) and nitrogen (d15N) are often sufficient to trace prey sources. However, in more complex systems, such as environments with diverse carnivores or those involving humans, trophic relationships remain partially or completely unresolved in isotopic studies. African terrestrial ecosystems are complex, hosting extraordinarily diverse mammalian communities. These ecosystems shaped the evolution of our species, yet now face risk of collapse as a result of increasing anthropogenic pressures. Yet, our understanding of trophic ecology in these complex ecosystems using current isotopic proxies yields ambiguous results, limiting our understanding of how these ecosystems have changed over time and when human impacts began. My 5-year research plan is to (1) to investigate changes in trophic position and diet source in mammals using recently developed trophic proxies of organic (d15NAA) and inorganic (d26Mg and d44Ca) biological tissues in African ecosystems, and (2) apply these approaches to investigations of human dietary change in the past in order to understand anthropogenic impact in prehistory. This project will lay the groundwork for understanding trophic connections in complex ecosystems (e.g., multi-tier trophic systems that include human impacts), illustrate shifting anthropogenic pressures from ancient to modern times, and create an analytical framework that can be used in complex terrestrial ecosystems globally. This project addresses a fundamental limitation of (paleo)ecological studies using new geochemical methods for understanding trophic links in systems where these links have been difficult to resolve with traditional methods. This project will also address fundamental questions of human diet and anthropogenic impacts in prehistory. This work will capitalize on the PI's >10 years of research experience and connections in eastern Africa, and will provide opportunities for students to conduct museum and lab-based research on these projects. We will also host a symposium on our work at the National Museums of Kenya in the project's final year to share our findings and create networking opportunities for young international scholars. This project will foster international collaborations, including academics from eastern Africa, as an ongoing effort to promote equity among the global community of scholars.

营养（消费者-猎物）动态是生态系统的基本组成部分。这些相互作用推动了全球生态系统功能和生物地球化学循环，并对过去和现在的气候变化和人类活动的影响敏感。饮食和营养相互作用的地球化学（同位素）代理是在无需直接观察的情况下追踪这些动态的关键工具，并且对于从保护到古科学的一系列领域至关重要。在简单的营养系统中，传统的稳定同位素如碳 (d13C) 和氮 (d15N) 通常足以追踪猎物来源。然而，在更复杂的系统中，例如具有多种食肉动物或涉及人类的环境，同位素研究中的营养关系仍然部分或完全未得到解决。非洲陆地生态系统非常复杂，拥有极其多样化的哺乳动物群落。这些生态系统塑造了我们物种的进化，但现在由于人为压力的增加而面临崩溃的风险。然而，我们使用当前同位素代理对这些复杂生态系统中营养生态的理解产生了模糊的结果，限制了我们对这些生态系统如何随时间变化以及人类影响何时开始的理解。 我的 5 年研究计划是 (1) 使用非洲生态系统中最近开发的有机 (d15NAA) 和无机 (d26Mg 和 d44Ca) 生物组织的营养替代物来研究哺乳动物营养位置和饮食来源的变化，以及 (2) 应用这些方法用于调查过去人类饮食的变化，以了解史前时期的人为影响。该项目将为理解复杂生态系统中的营养关系（例如，包括人类影响的多层营养系统）奠定基础，说明人类压力从古代到现代的变化，并创建可用于复杂陆地生态系统的分析框架全球。 该项目解决了（古）生态研究的基本局限性，使用新的地球化学方法来了解系统中的营养联系，而这些联系很难用传统方法解决。该项目还将解决史前人类饮食和人为影响的基本问题。这项工作将利用 PI 在东非超过 10 年的研究经验和联系，并将为学生提供对这些项目进行博物馆和实验室研究的机会。我们还将在该项目的最后一年在肯尼亚国家博物馆举办一次关于我们工作的研讨会，以分享我们的发现并为年轻的国际学者创造交流机会。该项目将促进包括东非学者在内的国际合作，作为促进全球学者界公平的持续努力。