EAGER: Development of a High-Resolution, Multi-Century Paleo-Fire Reconstruction from Tropical Australian Stalagmites

EAGER：利用澳大利亚热带石笋进行高分辨率、多世纪古火重建

• 批准号: 1812476
• 负责人: Rhawn Denniston
• 金额: $ 5.16万
• 依托单位: Cornell College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-02-01 至 2020-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1812476&HistoricalAwards=false
• 关键词: EAGER; Development; Resolution; Multi; Century

Fire plays a critical role in ecology, especially in the dry tropics such as the savannas of northwestern Australia. The pace and extent of the burning of vegetation and litter (biomass) in a region reflects both human activities and the amount and timing of rain and lightning. Attempts to understand historic rates of biomass burning are hampered by few continuous records, records of fire at annual resolution, and records that span multiple centuries. This project explores a new method of recording the occurrence of historic fires by measuring traces of organic chemicals produced by fires that are captured within cave stalagmites. The project focuses on stalagmites in a well-studied cave in northwest Australian to develop a multi-century-long record of fire activity. In addition, these stalagmites provide a detailed record for constructing a 3000-year history of summer monsoon rainfall. By combining the records contained in the stalagmites, researchers will provide the first millennial record of the role of human activity and monsoonal rains in shaping the landscape and ecology of the dry tropics. This new methodology is a potentially transformative approach to characterize fire occurrence, and would be of general value in understanding the historic role of fire in other regions of the planet. Such information is extremely useful to land managers. This project will also provide research training for students at a primarily undergraduate US institution.Polycyclic aromatic hydrocarbons (PAHs), including fluoranthene, pyrene, benzo(a)pyrene and indeno(1,2,3-c,d)pyrene, are produced by burning of biomass and are characterized by high persistence in the environment. PAHs have been recovered from lake sediments spanning several millennia and prior studies have used them to reconstruct fire histories of the surrounding watershed. The investigators have developed a novel method for the extraction of PAHs from stalagmites and preliminary PAH analyses using high resolution 230Th-234U dating methods of the stalagmite carbonate were consistent with satellite maps of burn scars in revealing that 2004 was the only year to experience a burn over the cave. PAHs in these stalagmites may thus represent an important new high-resolution record of prehistoric fire activity in tropical karst regions such as Western Australia and can complement the monsoon rainfall reconstructions extracted from the same samples. This EAGER award will extend the analysis of fire-related organic compounds in these stalagmites through the 17th century to capture changes in burn activity associated with (1) changes in land use associated with European settlement in the 1880s, and(2 changes in monsoon activity associated with the transition from the Little Ice Age to the Modern Era.

大火在生态学中起着至关重要的作用，尤其是在澳大利亚西北部稀树草原等干燥热带地区。一个地区植被和垃圾（生物量）燃烧的步伐和程度反映了人类活动以及雨水和闪电的数量和时间。几个世纪以来，几个世纪以来，几个世纪的记录，年度的火记录和记录，试图了解生物量燃烧的历史速率的尝试受到阻碍。该项目探讨了一种通过测量由洞穴石灰岩内捕获的火灾产生的有机化学物质的痕迹来记录历史火灾的新方法。该项目着重于澳大利亚西北部一个经过良好研究的洞穴中的Stalagmites，以发展跨越的火灾活动记录。此外，这些石匠还提供了建造夏季季风降雨3000年历史的详细记录。通过结合Stalagmites中包含的记录，研究人员将为人类活动和季风降雨在塑造干燥热带地区的景观和生态学中的作用提供第一个千禧年记录。这种新方法是一种表征火灾发生的潜在变革方法，并且在理解地球其他地区的火的历史作用方面将具有一般价值。这些信息对土地管理者非常有用。该项目还将为主要是本科美国机构的学生提供研究培训。生产氟氨基烃（PAHS），包括氟氨基，pyrene，benzo（a）pyrene（A）Pyrene和Indeno（1,2,3-C，D）Pyrene，Pyrene，Pyrene，通过燃烧生物量，其特征是环境中的持久性。 PAH已从数千年的湖泊沉积物中回收，先前的研究用它们来重建周围流域的火史历史。研究人员已经开发了一种新的方法，可以使用高分辨率230th-234U的碳酸盐酸盐碳酸盐症的高分辨率230th-234U约会方法从石stal虫中提取PAH和PAH分析，这与燃烧疤痕的卫星图是一致的在山洞上。因此，这些石质石质的PAH可能代表了热带喀斯特地区（例如西澳大利亚州）的史前火活性的重要新高分辨率记录，并可以补充从同一样品中提取的季风降雨重建。该急切的奖励将扩大对这些水生岩中火灾相关的有机化合物的分析到17世纪，以捕获与（1）与（1）1880年代与欧洲定居相关的土地使用变化相关的燃烧活动的变化，并且（季风活动的2个变化与从小冰河时代到现代时代的过渡有关。