Collaborative Research: How did Terrestrial Ecosystems Rebuild Following the Cretaceous/Paleogene Mass Extinction?

合作研究：白垩纪/古近纪大规模灭绝后陆地生态系统如何重建？

• 批准号: 2317668
• 负责人: Theodore Them
• 金额: $ 28.73万
• 依托单位: College of Charleston
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2028-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2317668&HistoricalAwards=false
• 关键词: Collaborative; Research; How; did; Terrestrial

During the Cretaceous/Paleogene (K/Pg) mass extinction (ca. 66 million years ago), ~75% of all species on Earth went extinct, notably including all non-avian dinosaurs. This event completely changed the trajectory of the evolutionary tree of life, leading ultimately to the formation of today’s mammal-dominated communities. The aftermath of the K/Pg mass extinction represents a natural laboratory in which ecosystem reorganization can be studied with high geologic resolution. Some studies have been undertaken to examine how marine ecosystems were rebuilt, but the response of terrestrial environments is poorly documented. This project will examine ecological and environmental changes that occurred on land across the K/Pg boundary in the Rocky Mountain region of the western United States. The research will involve extensive paleontological and geochemical analyses of existing fossil collections and introduce novel data that will reveal the variability in the timing and pattern of terrestrial ecosystem rebuilding after the mass extinction. This project will expand knowledge of a major turning point in the history of life on Earth that will help determine how the biodiversity of ecosystems recover at the continental scale and how modern terrestrial biota evolved. The results may also provide data for conservation biologists to predict the long-term consequences of current rapid changes in biodiversity and help inform conservation priorities to alleviate ecosystem disruptions. The project will use established programs in classrooms, museum exhibits, and outreach at the participating institutions to reach audiences of multiple ages and backgrounds.The K/Pg mass extinction completely changed the trajectory of the evolutionary tree of life and most research has focused on marine systems. Post-extinction patterns of ecosystem restructuring on land, fundamental to understanding the evolution of the modern taxa of mammals and plants, have received little attention because fossil collections, data, and high-resolution chronostratigraphic sections are relatively rare. This project will build on extensive fossil collections from three primary study areas in the Western Interior of North America, involve new fieldwork designed to augment collections and data from critical intervals, and develop diverse inorganic and organic geochemical records to characterize and identify biotic patterns, local environments, and factors involved in terrestrial ecosystem restructuring following the K/Pg extinction. To accomplish these goals, the research team will: collect and interpret megafloral, palynological, invertebrate, and vertebrate fossils and associated contextual data from three well-studied stratigraphic sections; use fossil leaf physiognomic traits and geochemical data from organic compounds to construct records of temperature, precipitation, and fire frequency; integrate ecological proxies of community structure and environmental conditions over time and space as they relate to the three study areas, to determine if there are any climatic conditions, geographic locations, or trophic interactions that enhance or impede ecosystem restructuring after the K/Pg extinction. In addition, geochemical proxies for volcanic activity will be examined to resolve the influence of the extensive basalt eruptions of the Deccan Traps on the biota within the study areas.This project is jointly funded by Frontier Research in Earth Sciences (FRES) and the Established Program to Stimulate Competitive Research (EPSCoR).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.

在白垩纪/古生元（K/PG）质量扩展期间（约6600万年前），地球上所有物种中约有75％灭绝了，特别是包括所有非avian恐龙。这一事件完全改变了生命的进化树的轨迹，最终导致了当今以哺乳动物为主的社区的形成。 K/PG质量扩展的后果代表了一个自然实验室，在该实验室中，生态系统重组可以通过高地质分辨率进行研究。已经进行了一些研究，以研究如何重建海洋生态系统，但陆地环境的反应很少。该项目将检查在美国西部落基山地区K/PG边界的土地上发生的生态和环境变化。这项研究将涉及现有化石收集的广泛古生物学和地球化学分析，并引入新的数据，以揭示质量扩展后陆地生态系统重建的时机和模式的可变性。该项目将扩大对地球生活历史上一个主要转折点的知识，这将有助于确定生态系统的生物多样性如何在连续规模上恢复，以及现代陆地生物群的发展方式。结果还可以为保护生物学家提供数据，以预测当前生物多样性快速变化的长期后果，并有助于为保护优先级提供信息，以减轻生态系统破坏。项目将在教室，博物馆展览和参与机构的宣传中使用已建立的计划，以吸引多个年龄和背景的受众。K/PG质量扩展完全改变了生命进化树的轨迹，大多数研究都集中在海洋系统上。生态系统在陆地上恢复的爆发后灭绝模式，这是了解现代哺乳动物和植物的现代分类群的基础，因为化石收集，数据和高分辨率的年度地层学部分相对罕见，因此很少受到关注。该项目将以北美西部内部三个主要研究区域的广泛化石收集为基础，涉及新的实地调查，旨在从关键间隔中增加收集和数据，并开发潜水员无机和有机的地球化学记录，以表征和识别生物模式，本地环境，以及在K/PGESTERSINS恢复陆地生态系统中涉及的生物生物模式，局部环境以及涉及的因素。为了实现这些目标，研究小组将：收集和解释来自三个经过深入研究的地层阶层的大型，孢子，无脊椎动物和脊椎动物化石以及相关的上下文数据；使用来自有机化合物的化石叶子型型和地球化学数据来构建温度，降水和火频率的记录；与三个研究领域相关的社区结构和环境条件的综合生态代理，以确定在K/PG扩展后是否存在任何慢性条件，地理位置或营养相互作用，可以增强或阻碍生态系统恢复。此外，将检查地球化学代理，以解决研究领域内的Deccan陷阱对Biota的广泛玄武岩爆发的影响。该项目由地球科学领域的边境研究（FRES）共同资助（FRES）（FRES）和既定计划，并通过启发竞争性研究（EPSCOR）进行了反映的代表。智力优点和更广泛的影响审查标准。