Isotopic and non-isotopic tracers for biogeochemical cycles of nutrients in pristine and impacted watersheds

用于原始流域和受影响流域营养物生物地球化学循环的同位素和非同位素示踪剂

• 批准号: RGPIN-2019-05629
• 负责人: Schiff, Sherry
• 金额: $ 3.72万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=750861
• 关键词: Isotopic; non; isotopic; tracers; biogeochemical

Nutrients drive aquatic freshwater ecosystems in terms of their food webs, productivity and suitability as sources of drinking water for humans. Biogeochemical cycling of nutrients involves both major nutrients (carbon, nitrogen, phosphorus, oxygen) and minor nutrients, especially those that change form depending on oxygen conditions (iron, sulfur, trace metals). These interlinked cycles are complex and it can be difficult to tease apart critical processes and controls on their rates. Prediction of changes in nutrient cycling due to human activities (agriculture, mining, forestry) and climatic changes (precipitation, temperature and storms) requires this knowledge. Tracers provide insight that is not obtainable from other methods. In our longstanding, internationally successful research program, we have acquired specialized expertise in the use of naturally occurring isotopes of elements and other tracers. Our long term goal is to develop and apply tracers to provide insight into key biogeochemical processes in northern, forested and human impacted watersheds.      This NSERC Discovery Grant proposal builds on a number of recent discoveries in our research program. Four interrelated projects have been selected, all with the common theme of strategic use of tracers for addressing freshwater issues of concern to Canadian society. All projects have graduate student research at their core and involve development of new techniques and approaches, capitalizing on advances in analytical technology and novel information available from DNA of organisms that cycle nutrients. These projects are: 1. Changing the paradigms for CH4, a potent greenhouse gas: implications for CH4 emissions to the atmosphere, effect of changing nutrients, recently discovered novel organisms and isotopic tracing of food webs; 2. Interlinked cycles of iron and organic matter in lakes: new techniques for iron isotopes and dissolved organic matter (DOM) for formation of harmful algal blooms and partitioning of carbon between sediments (carbon sequestration) and release to the atmosphere as a greenhouse gas; 3. High DOM environments in subarctic Canada: implications for drinking water supplies for northern communities including the efficacy of disinfection processes and production of disinfection by-products, and a Canadian contribution to the NASA program on carbon emissions; and 4. Changing nutrient cycles in nutrient poor High Arctic Canadian watersheds. The last two projects include sustained field activities by students in the subarctic (64-67°N) and high Arctic (82°N) and are the subject of a Northern Research Supplement application. Through our extensive national and international collaborations with a variety of stakeholders from government, indigenous communities and non-profits who require science-based information for decisions, our students are uniquely poised to contribute their expertise to Canadian society.

营养物质在水生淡水生态系统的食物网、生产力和作为人类饮用水来源的适用性方面推动着水生淡水生态系统。营养物质的生物地球化学循环既包括主要营养物质（碳、氮、磷、氧），也包括次要营养物质，特别是那些根据氧气条件改变形态的营养物质（铁、硫、微量金属）。这些相互关联的循环是复杂的，很难梳理出关键的过程和对其速率的控制。由于人类活动（农业、矿业、林业）和气候变化（降水、温度和风暴）导致的养分循环变化的预测需要这些知识。跟踪器提供了其他方法无法获得的洞察力。在我们长期的、国际上成功的研究项目中，我们已经获得了使用自然存在的元素同位素和其他示踪剂的专业知识。我们的长期目标是开发和应用示踪剂，以深入了解北部、森林和人类影响的流域的关键生物地球化学过程。这项NSERC发现拨款提案建立在我们研究计划中最近的一些发现的基础上。选定了四个相互关联的项目，所有项目的共同主题都是战略性地利用示踪剂来处理加拿大社会关心的淡水问题。所有项目都以研究生研究为核心，涉及新技术和新方法的开发，利用分析技术的进步和从循环营养物质的生物体DNA中获得的新信息。这些项目是：1；CH4（一种强效温室气体）模式的改变：对大气中CH4排放的影响，营养物质变化的影响，最近发现的新生物和食物网的同位素追踪；2. 湖泊中铁和有机物的相互联系循环：铁同位素和溶解有机物（DOM）的新技术，用于形成有害藻华和沉积物之间的碳分配（碳固存）并作为温室气体释放到大气中；3. 加拿大亚北极地区高DOM环境：对北部社区饮用水供应的影响，包括消毒过程的效力和消毒副产品的生产，以及加拿大对美国宇航局碳排放方案的贡献；和4。营养物贫乏的加拿大高北极流域中不断变化的养分循环。最后两个项目包括学生在亚北极（64-67°N）和高北极（82°N）的持续实地活动，是北方研究补充申请的主题。通过我们与来自政府、土著社区和非营利组织的各种利益相关者的广泛的国内和国际合作，他们需要基于科学的信息来决策，我们的学生有独特的准备为加拿大社会贡献他们的专业知识。