Collaborative Research: Testing for nutrient limitation in alpine snow algae ecosystems

合作研究：测试高山雪藻生态系统的养分限制

• 批准号: 2113784
• 负责人: Trinity Hamilton
• 金额: $ 63.25万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2113784&HistoricalAwards=false
• 关键词: Collaborative; Research; Testing; nutrient; limitation

Climate change is driving massive changes in the amount of frozen water present on Earth (the cryosphere). An increasingly well-recognized factor that interacts with climate change to amplify the melting of ice and snow is the proliferation of algae that bloom on the snow surface (snow algae). Current understanding of the factors that control the abundance of snow algae, and thus their impact on snow and ice melt, is incomplete, especially in alpine environments where glaciers and snowfields are critical components of the water supply and are particularly susceptible to climate change. This project will examine an important but understudied driver of snow algae abundance – the variable input of key nutrient elements (nitrogen and phosphorus) via atmospheric deposition (in snow, rain, and dust). This project leverages and develops the capacities of an interdisciplinary team involving faculty, a postdoctorate, a graduate student, and undergraduates in a project of broad societal relevance given the crucial role of mountain snow in water supplies globally. Collectively, these studies will be among the first to explicitly test for nutrient limitation of alpine snow algae, significantly enhancing current understanding of how nutrient supplies drive large-scale ecosystem dynamics in the cryosphere. In particular, this information is critical for understanding and forecasting the role of snow algae in driving cryosphere loss, a process that ultimately has major impacts on sea level rise and freshwater supply. Project personnel will develop and deliver a unique “Cryosphere Ecology” undergraduate field class that will integrate key topics and concepts in ecosystem ecology, microbiology, and snow science. Public outreach will include contacts with water resource stakeholders and managers as well as communication to broader audiences via existing public outreach channels.This research will examine the impacts of nitrogen and phosphorus inputs on snow algae in six study regions in the western USA across a gradient of atmospheric nutrient deposition. The project has three focal questions: 1) How are snow algae biomass, productivity, and carbon:nitrogen:phosphorus ratios related to patterns of nutrient (nitrogen, phosphorus) deposition and availability in mountains of the western USA? 2) How do these snow algae ecosystems respond to experimental nutrient enrichment? 3) How does proliferation of nutrient-driven snow algae affect albedo properties of snow and thus accelerate snow melt? To answer these questions, this project will assess how snow algae proliferate in snow formed from meltwater from the six study regions (using the unique capacity of the Subzero Research Laboratory at Montana State University) and test how nitrogen and phosphorus enrichment affect snow algae growth and its impact on albedo and melting under both field and laboratory conditions. Answering these questions will produce novel fundamental knowledge of the role of nutrient limitation in snow algae ecosystems and the connection between nutrient inputs and biological albedo reduction, facilitating better forecasting of snowmelt-driven water supplies in mountain regions and providing a basis for mitigating processes that drive inputs and transport of atmospheric pollutants. The project will also support development of an interdisciplinary course in cryosphere ecology, encompassing snow science, biogeochemistry, microbiology, and phycology.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.

气候变化正在导致地球（冰冻圈）上存在的冰冻水量发生巨大变化。人们越来越认识到，与气候变化相互作用、加速冰雪融化的因素是雪表面藻类的繁殖。 （雪藻）目前对控制雪藻丰度的因素以及它们对冰雪融化的影响的了解还不完整，特别是在冰川和雪原是供水的关键组成部分的高山环境中。该项目将研究雪藻丰度的一个重要但尚未得到充分研究的驱动因素——通过大气沉降（在雪、雨和灰尘中）的关键营养元素（氮和磷）的可变输入。鉴于山地积雪在全球供水中的关键作用，这些研究将成为首批明确的研究之一，并在具有广泛社会意义的项目中培养跨学科团队教师、博士后、研究生和本科生的能力。高山雪藻的营养限制测试，显着增强了目前对营养供应如何驱动冰冻圈大规模生态系统动态的理解，特别是，这些信息对于理解和预测雪藻在驱动冰冻圈消失过程中的作用至关重要。最终对海平面上升和淡水供应产生重大影响的项目人员将开发并提供独特的“冰冻圈生态学”本科生实地课程，该课程将整合生态系统生态学、微生物学和雪科学的关键主题和概念，包括接触。和水资源利益相关者和管理者，以及通过现有的公共宣传渠道与更广泛的受众进行沟通。本研究将研究美国西部六个研究区域的氮和磷输入对大气养分沉降梯度的影响。有三个焦点问题：1）雪藻生物量、生产力和碳：氮：磷比率与美国西部山区养分（氮、磷）沉积和可用性的模式有何关系？雪藻生态系统对实验性营养富集有何反应？ 3）营养驱动的雪藻的增殖如何影响雪的反照率特性，从而加速雪的融化？为了回答这些问题，该项目将评估雪藻如何在融水形成的雪中增殖？六个研究区域（利用蒙大拿州立大学零度以下研究实验室的独特能力）并在现场和实验室测试氮和磷富集如何影响雪藻生长及其对反照率和融化的影响回答这些问题将产生关于雪藻生态系统中养分限制的作用以及养分输入与生物反照率降低之间的联系的新的基础知识，有助于更好地预测山区融雪驱动的水供应，并为缓解过程提供基础。该项目还将支持冰冻圈生态学跨学科课程的开发，包括雪科学、生物地球化学、微生物学和藻类学。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，NSF 的法定使命被认为值得支持。