Plant-Insect Diversity, Paleobiology, and Paleobiogeography From Early Eocene Neotropical Forests

始新世早期的高温是发生在约5600万年至5200万年前的快速和极端变暖的间歇期。超高温记录了过去6600万年来全球最高温度，它们的化石记录提供了温室世界中生命的快照。大多数关于这些变暖期间生命的研究都集中在热带和极地之间的地理区域。人们对始新世早期的古热带森林知之甚少。在该项目中，正在对哥伦比亚北部早始新世植物化石记录进行密集采样。这些收集将提供一个独特的、以前没有描述过的中美洲和南美洲植物的记录，根据这些记录，可以根据过去的环境变化来评估它们的进化和功能。有了这样的记录，我们对热带雨林的极限和对变暖的长期反应的理解将会进步。该项目将培养本科生在最先进的实验室技术方面的科学培训。调查人员将通过培训公立学校教师，继续提高哥伦比亚当地和农村社区的古生物意识。该项目将使用哥伦比亚北部的古植物学和沉积记录来测试新热带森林对始新世早期变暖事件的生物响应。研究区域包括三个以前未描述的植物化石地点，这些地点跨越古新世-始新世边界，补充了先前在哥伦比亚描述的晚古新世植物群。考虑到植物化石记录提供了一个观察热带雨林对气温升高的长期响应的自然实验，该项目集中于4个问题：1)早期始新世过热是否导致南美洲北部热带生物群的多样化或崩溃？2)植物蒸发冷却在快速升温期间发生变化吗？3)始新世早期森林组成和植物-昆虫相互作用如何变化？4)南美洲北部早期始新世森林在生物地理组成上与同一地区现存森林相似吗？通过让本科生研究这些研究问题，这个项目将促进发现和理解，同时促进教学、培训和学习。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The early Eocene hyperthermals were intervals of rapid and extreme warming that occurred ~56-52 million years ago. The hyperthermals recorded the highest global temperatures in the last 66 million years, and their fossil record provides a snapshot of life in a greenhouse world. Most studies of life during these warming intervals have focused on geographical regions between the tropics and poles. Very little is known about ancient tropical forests during the early Eocene. In this project, the early Eocene plant fossil record of northern Colombia are being intensively sampled. These collections will provide a unique and previously undescribed record of Central and South American plants from which their evolution and function can be evaluated in relation to past environmental change. With such records, our understanding of the limits and long-term responses of tropical rainforests to warming will advance. This project will foster the scientific training of undergraduate students in state-of-the-art lab techniques. The investigators will continue to increase paleontological awareness in local and rural communities in Colombia through training of public school teachers. This project will use the paleobotanical and sedimentary record from northern Colombia to test for biotic responses of Neotropical forests to early Eocene warming events. The research area includes three previously undescribed plant fossil localities that span the Paleocene-Eocene boundary and complement previously described Late Paleocene floras in Colombia. Considering that the plant fossil record provides a natural experiment in which to observe the long-term response of tropical rainforests to temperature increases, this project is focussing on 4 questions: 1) Did the early Eocene hyperthermals lead to a diversification or a collapse of tropical biomes in northern South America? 2) Did plant evaporative cooling change during these rapid increases in temperature? 3) How did forest composition and plant-insect interactions change during the early Eocene? 4) Were the early Eocene forests in northern South America similar in biogeographic composition to extant forests in the same region? By involving undergraduates in examining these research questions, this project will advance discovery and understanding while promoting teaching, training, and learning.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.