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: 1623885
• 负责人: Luis Chiappe
• 金额: $ 39.7万
• 依托单位: Los Angeles County Museum of Natural History Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-15 至 2021-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1623885&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(“食物网”)之间的觅食关系，这可能会使它们在未来面临更大的灭绝风险。该项目将研究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12000年前最后一个冰河时代结束时的重大变化(人类到来、大型哺乳动物的丧失和气候变化)之前建立冰河时代的食物网。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面临最大的灭绝风险，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到这项研究中使用的化石的鉴定中。项目发现还将在La Brea焦油坑和博物馆的新展品中分享，这些展品每年吸引35万名参观者。在这个项目中，来自多个沥青渗漏的沉积物将被取样用于La Brea焦油坑(美国加利福尼亚州)的小动物、昆虫和植物。化石将被识别，放射性碳年代测定，然后在更新世末大范围的环境剧变之前的4万年里整合到多营养的古食物网中。以前，只对上层营养水平(特别是食肉动物)进行了详细调查；增加的信息将测试食物网特性，以预测物种对全球变化的敏感性。S项目-新型贝叶斯框架，用于重建生物量流动，通过促进多个替代物的集成来表征营养相互作用中的不确定性，将对古和现代食物网研究都有用。