Collaborative Research: Assessing millennial-scale community dynamics using highly-resolved mammal and vegetation food webs

合作研究：利用高分辨率的哺乳动物和植物食物网评估千禧年规模的群落动态

• 批准号: 1623840
• 负责人: Jacquelyn Gill
• 金额: $ 29.65万
• 依托单位: University of Maine
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-15 至 2019-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1623840&HistoricalAwards=false
• 关键词: Collaborative; Research; Assessing; millennial; scale

The extinction of Earth's largest animals is radically changing the feeding relationships among other species ("food webs") which may place them at greater risk of extinction in the future. This project will examine Rancho La Brea tar pits for the complete fossil record (large carnivores to plants) and build ice age food webs prior to the major changes at the end of the last ice age 12,000 years ago (human arrival, the loss of large mammals, and climate change). Understanding the relationships among ice age animals and plants will help biologists predict which species were at most risk of extinction and apply these model predictions to present-day biodiversity. This project is also an excellent opportunity to support science education and diversity, by directly involving middle school students in California and Maine in the identification of fossils used in this research. Project findings will also be shared in new La Brea Tar Pits & Museum exhibits, which draw 350,000 visitors each year. For this project, sediments from multiple asphalt seeps will be sampled for the small animals, insects and plants of the La Brea Tar Pits (California, USA). Fossils will be identified, radiocarbon dated, and then integrated into multi-trophic paleo food webs over the 40,000 years before the widespread environmental upheaval at the end of Pleistocene. Previously only the upper trophic levels (particularly carnivores) were investigated in detail; added information will test food web properties for predicting the sensitivity of species to global change. The project?s novel Bayesian framework, employed to reconstruct biomass flow, will be useful to both paleo and modern food web studies by facilitating integration of multiple proxies to characterize uncertainty in trophic interactions.

地球上最大动物的灭绝正在从根本上改变其他物种之间的进食关系（“食物网”），这可能使它们在未来面临更大的灭绝风险。该项目将检查兰乔拉布雷亚焦油坑的完整化石记录（大型食肉动物到植物），并在 12,000 年前最后一个冰河时代结束时的重大变化（人类到来、大量生物的丧失）之前建立冰河时代的食物网。哺乳动物和气候变化）。了解冰河时代动植物之间的关系将有助于生物学家预测哪些物种最有灭绝的风险，并将这些模型预测应用于当今的生物多样性。该项目也是支持科学教育和多样性的绝佳机会，直接让加利福尼亚州和缅因州的中学生参与本研究中使用的化石鉴定。项目成果还将在新的拉布雷亚焦油坑和博物馆展览中分享，每年吸引 350,000 名游客。在该项目中，将从多个沥青渗漏的沉积物中采集拉布雷亚焦油坑（美国加利福尼亚州）的小动物、昆虫和植物样本。化石将被鉴定、放射性碳测年，然后被整合到更新世末期广泛的环境剧变之前 4 万年的多营养古食物网中。以前仅对上层营养级（特别是食肉动物）进行了详细研究；补充信息将测试食物网特性，以预测物种对全球变化的敏感性。该项目新颖的贝叶斯框架用于重建生物量流，通过促进多个代理的整合来表征营养相互作用的不确定性，将有助于古和现代食物网研究。