RUI: The Timing and Evolution of Devonian Fire Systems and Their Implications for Atmospheric Oxygen Concentration

GSTDTAP

项目编号	1828359
	RUI: The Timing and Evolution of Devonian Fire Systems and Their Implications for Atmospheric Oxygen Concentration
	Ian Glasspool
主持机构	Colby College
项目开始年	2018
	2018-09-01
项目结束日期	2021-08-31
资助机构	US-NSF
项目类别	Standard Grant
项目经费	231571(USD)
国家	美国
语种	英语
英文摘要	Charcoal can be preserved in the rock record, and so it is an excellent indicator of wildfire activity in deep-time. The earliest known charcoal evidence of wildfires dates from about 420 million years ago when there were no trees and plants were extremely small and moss-like. These plants required very wet environments for growth and reproduction. The small size of plants and their dependence on moist conditions means that they should be a poor source of fuel for wildfires. However, there are a significant number of sites from this time 420-400 million years ago that preserve charcoal and thus evidence of ancient wildfires. There are very few charcoals preserved over the following 30 million years, which is surprising since vegetation around the world became larger and more independent of water and so a better source of fuel for fire. This proposal aims to investigate rocks from North America deposited during the time interval from 420-359 million years ago (the Devonian Period) when evidence of wildfires is lacking. This study will assess whether this anomaly in fire abundance really exists and what factors may have controlled it, including whether oxygen in the atmosphere may have been too low to have supported fires. Undergraduate interns will be engaged in the project and trained in fieldwork and laboratory techniques related to the study of fossil charcoal. At a time when the global impact of fires on many communities is growing, this project will provide these undergraduates an opportunity to share topical and exciting results on fires in deep time with both the scientific community and, through online content, the broader general public. Preliminary evidence indicates that global fire occurrences during the Early to Mid-Devonian were not affected primarily by fuel but rather, flammability was governed by atmospheric oxygen concentration (pO2). This master variable of the Earth system is considered to have profoundly impacted metazoan evolution, but its quantification in deep time is uncertain. This proposal aims to test the hypothesis that pO2 was the primary driver of fire occurrence at this time by seeking and isolating charcoal from a range of North American Devonian-age sedimentary settings and assessing it in terms of sedimentary setting, taxonomy and petrographic characteristics. Comprehensively determining early fire regime evolution will afford new insights into the evolution of fire feedback into biogeochemical cycles and will permit models of pO2 during the Devonian to be critically examined. These data will collectively provide base level insights into environmental change during this key interval in the terrestrialization of Earth. Undergraduate interns will be engaged in the project and trained in fieldwork and laboratory techniques related to the study of fossil charcoal. These undergraduates will continue their projects during the academic year as capstones and disseminate their results through presentations at conferences and through collaboration in scientific publications. 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.
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/73257
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Ian Glasspool.RUI: The Timing and Evolution of Devonian Fire Systems and Their Implications for Atmospheric Oxygen Concentration.2018.