Collaborative Research: A Continuous 60,000 Year Sediment Record Documenting Abrupt to Precession-Scale Climate Change and Ecosystem Response at Fish Lake UT, Upper CO River Basin

合作研究： 60,000 年的连续沉积物记录记录了科罗拉多州上游流域鱼湖 UT 的突然进动规模的气候变化和生态系统响应

• 批准号: 2102997
• 负责人: Jesse Morris
• 金额: $ 30.04万
• 依托单位: University of Utah
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2102997&HistoricalAwards=false
• 关键词: Collaborative; Research; Continuous; 60; 000

Over the last several decades increased drought severity and wildfire intensity around the globe has drawn attention to a need for an improved understanding of how climate change over a human lifetime impacts people, ecosystems, and water resources. Rapid population growth in the arid western US combined with pervasive drought, temperature stress on forests, insect outbreaks, and unprecedented wildfires has negatively impacted people and the economy and focused attention on the need to improve our understanding of the controls and long-term consequences of increased climate stress on these valuable and unique ecosystems. This interdisciplinary project will place the 21st century drought and extreme fire seasons in western North America into a longer-term context as a means to identify likely future scenarios for climate change and ecosystem response. This research will use a long and continuous sediment lake record collected from a headwater lake in the upper Colorado River Basin to investigate past variations in precipitation and temperature, and the impacts these changes had on vegetation, wildfire, forest disturbance, and glaciation with special attention paid to periods of rapid climate change that has happened in the past over timescales relevant to people. This is possible because of the high accumulation rate of Fish Lake sediments of about 18.5 meters over the last 60,000 years producing a 60 foot high section of mud containing things like pollen, charcoal, bug parts, fish bones, and other fossils for researchers to study in addition to the sediment itself and the molecular fossils it preserves. The proposed work includes X-ray Fluorescence (XRF) and CT core scanning to identify abrupt sediment boundaries and characterize the sediment profiles at the highest possible resolution. Changes in precipitation and evaporation will be investigated by water isotope tracers, including leaf wax delta-2H (long and short chain) and chironomid delta-18O. Molecular fossils such as branched glycerol dialkyl glycerol tetraethers (brGDGTs) will be used as way to estimate past summer temperatures through time. Landscape and aquatic ecosystem responses will be studies by using pollen, charcoal, polycyclic aromatic hydrocarbons (PAHs), biogenic silica, and organic carbon, nitrogen and stable isotopes. Watershed erosion and glacial activity of the Fish Lake Plateau will be investigated in new detail with scanning XRF, grainsize, organic matter, biogenic silica, and bulk density. Successful dating of an 11-m long core recovered in 2014 has been demonstrated by radiometric methods, including 210Pb and AMS 14C of terrestrial macrofossils and charcoal, by tephrochronology, and by paleomagnetic measurements.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.

在过去的几十年中，全球的干旱严重程度和野火强度提高了人们的注意，人们需要提高人们对人类一生中气候变化如何影响人们，生态系统和水资源的需求。美国干旱西部的人口迅速增长，加上普遍的干旱，对森林的温度压力，昆虫暴发和前所未有的野火对人们和经济产生了负面影响，并将注意力集中在人们对控制措施的理解和长期对这些有价值和独特的生态系统增加的理解和长期后果的需求上。这个跨学科的项目将使北美西部的21世纪干旱和极端的火灾季节进入长期环境，以此作为确定气候变化和生态系统反应的未来情况的一种手段。这项研究将使用从科罗拉多州河流河流河流的脑海中收集的长而连续的沉积物湖泊记录，以调查过去的降水和温度的差异，这些变化对植被，野火，森林干扰以及对过去与人们相关的时代与人们相关的快速气候变化时的影响产生了影响。这是可能的，因为在过去的60，000年中，鱼湖沉积物的高积累速率高约18.5米，产生了60英尺高的泥浆，其中含有花粉，木炭，虫子零件，鱼骨和其他化石，供研究人员进行研究，以便研究沉积物本身以及分子化石。拟议的工作包括X射线荧光（XRF）和CT核心扫描，以识别突然的沉积物边界并以最高可能的分辨率表征沉积物曲线。水同位素示踪剂将研究降水量和蒸发的变化，包括叶蜡三角洲-2H（长链和短链）和Ghironomid Delta-18o。分子化石，例如分支的甘油二二甲基甘油四颗粒（BRGDGT），将以随着时间的推移估算过去夏季温度的方式。景观和水生生态系统的反应将是使用花粉，木炭，多环芳烃（PAHS），生物二氧化硅和有机碳，氮和稳定的同位素进行研究。鱼湖高原的分水岭侵蚀和冰川活性将通过扫描XRF，晶粒，有机物，生物二氧化硅和散装密度进行新的细节研究。通过辐射方法，包括210pb和AMS 14C的陆地宏观化石和木炭，通过Tephrognetic测量值以及古磁测量值的射线计证明了2014年回收11米长的核心的成功约会。该奖项反映了NSF的法定任务，并反映了通过评估的构成群体的构成群体，并反映了构成群体的范围。