Doctoral Dissertation Research: A Paleolimnological Investigation of Climate and Nitrogen Impacts on Primary Producers in Greenland Lakes and Community Water Supplies

博士论文研究：气候和氮对格陵兰湖泊和社区供水初级生产者影响的古湖泊学调查

• 批准号: 2330271
• 负责人: Yarrow Axford
• 金额: $ 5.38万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-04-01 至 2026-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2330271&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Paleolimnological; Investigation

This doctoral dissertation research improvement project will use ancient lake sediment records to reconstruct 5,000-year histories of ecosystem changes in Arctic lakes that are of particular relevance to Northern communities. Though many remote Arctic villages rely on lakes for critical ecosystem services like drinking water reserves and agricultural irrigation, these small water supplies are insufficiently monitored and their susceptibility to changing climate and land use have been minimally investigated. This study will examine what factors, including temperature and nutrient inputs, have most influenced the biological productivity and diversity of photosynthetic organisms in Arctic lakes over multi-decadal and multi-millennial timescales. A second goal of this study is to provide formal training to the doctoral student in building international collaborations between U.S. scientists and Arctic Indigenous communities. The doctoral student will foster relationships between the United States and Greenland as a foundation for a career in collaborative research that incorporates local and Indigenous knowledge for the benefit of Northern communities. In response to warming in Arctic regions that outpaces global trends by four-fold, Arctic landscapes are “greening” and ecosystems, including those within lakes, are becoming more productive. This work examines the roles of temperature shifts and changing nitrogen cycling in driving changes in algal and cyanobacterial communities in lakes. This project employs a novel methodology to assess productivity through quantifying numerous sedimentary pigments. Pigments have many strengths as proxies, including their organism class or taxonomic specificity and their ability to reflect organisms that do not produce hard macrofossils, which are particular assets for work that aims to understand trends in cyanobacterial communities. Quantifying sedimentary pigments of different organisms can both provide insight on what drives bulk primary productivity and characterize how individual groups of primary producers might respond. This research will advance the use of this underutilized methodology, which is potentially applicable in many regions where changing lacustrine algal or cyanobacterial communities and/or eutrophication are a societal concern.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.

这项博士论文研究改进项目将利用古代湖泊沉积物记录来重建北极湖泊 5000 年的生态系统变化历史，这与北方社区特别相关，尽管许多偏远的北极村庄依赖湖泊提供关键的生态系统服务，如饮用水储备和水源。农业灌溉中，这些小型供水系统没有得到充分监测，并且对气候和土地利用变化的敏感性也进行了最低限度的调查。本研究将探讨哪些因素（包括温度和养分投入）对光合生物的生物生产力和多样性影响最大。这项研究的第二个目标是为博士生提供在美国科学家和北极土著社区之间建立国际合作的正式培训。格陵兰岛是融合当地和土著知识以造福北方社区的合作研究事业的基础 为了应对北极地区变暖速度超过全球趋势四倍的情况，北极景观和生态系统正在“绿化”，包括。这项工作研究了温度变化和氮循环变化在驱动湖泊中藻类和蓝藻群落变化中的作用。该项目采用了一种新颖的方法，通过量化许多沉积色素来评估生产力。作为代理的优势，包括其生物体类别或分类学特异性以及它们对生物体的能力反映不产生坚硬的宏观化石，这是旨在了解蓝藻趋势的工作的特殊资产量化不同生物体的沉积色素既可以深入了解初级生产力的驱动因素，也可以描述初级生产者的各个群体可能如何反应，这项研究将推动这种未充分利用的方法的使用，该方法可能适用于许多湖泊变化的地区。藻类或蓝藻群落和/或富营养化是一个社会问题。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。