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.

该博士学位论文研究改进项目将使用古湖沉积物记录来重建与北部社区特别相关的北极湖泊生态系统变化历史。尽管许多偏远的北极村都依靠湖泊来用于饮用水储量和农业灌溉等关键生态系统服务，但这些小型水的供应量不足，并且对气候变化和土地使用的敏感性很小。这项研究将研究哪些因素，包括温度和养分输入，最大程度地影响了北极湖中光合组织的生物生产力和多样性，而多年元和多千年时间表。这项研究的第二个目标是向博士生提供正规培训，以在美国科学家和北极土著社区之间建立国际合作。博士生将促进美国与格陵兰之间的关系，以此作为合作研究职业的基础，该研究纳入了北部社区利益的本地和土著知识。为了回应北极地区的变暖，北极趋势超过了四倍，北极景观是“绿色”，包括湖泊内部的生态系统变得越来越有生产力。这项工作研究了温度转移的作用以及氮循环在驱动湖泊和蓝细菌群落变化中的变化。该项目采用一种新颖的方法来评估生产力，通过量化众多沉积物色素。颜料具有许多优势作为代理，包括其有机体类别或分类特异性及其反映不产生硬化石的生物的能力，这是旨在了解氰基群社区趋势的特殊资产。量化不同生物体的沉积物色素都可以提供有关驱动大量主要生产力的原因，并表征单个主要生产者群体的反应方式。这项研究将推动这种利用不足的方法的使用，该方法可能适用于许多地区，在许多地区，湖间藻类或蓝细菌或蓝细菌社区和/或富营养化是社会上的关注。这项奖项反映了NSF的法定任务，并且通过评估该基金会的智力优点和广泛的影响，认为NSF的法定任务被认为是珍贵的支持。