Acquisition of Instrumentation to Enhance Faculty-Student Biogeoscience Research: Linking Aquatic and Terrestrial Ecosystems Through Element Analysis

该合同将为生物地球科学研究采购以下仪器：燃烧元素分析仪，现有流动注射分析仪的自动采样器/稀释器升级，以及水净化系统。这些仪器将直接支持圣奥拉夫的各种生态系统研究，同时在正式课程和独立研究中扩大生物地球科学和生态学本科生的研究培训机会。该研究的主要目标是通过元素分析将水生和陆地生态系统联系起来。获得燃烧元素分析仪将允许分析沉积物有机质的C/N比率，有助于区分陆地和水生来源。元素分析仪与升级后的自动采样器/稀释器相结合，将允许在明尼苏达州和马尼托巴省继续工作，并将这项工作扩大到包括在蒙古西部收集的沉积物。第二组项目将集中于整合加州北部河流生态系统中食物网结构、营养螺旋和生态化学计量的理论。生态学家长期以来对生物群落对碳、氮、磷通量的影响感兴趣。生态化学计量理论为研究食物网中的营养通量以及食物网结构对多种营养物质运输和保留的影响提供了一个框架。本研究需要能够测量多种材料的C、N、P浓度，包括水样和藻类、植物、动物组织。这些新仪器将大大提高收集必要数据的能力，以探索和更好地了解这些过程。这些工具将被学院的本科生广泛使用，该学院在提供研究型课程和通过一个活跃的有50多名学生的暑期研究项目促进学生与教师的研究合作方面有着悠久的历史。两位pi都与本科生和全国其他机构的研究人员进行了广泛的合作。该研究具有广泛的社会应用价值，涉及放牧方式变化和气候变化对河流、湖泊和陆地生态系统生物地球化学和群落生态学的影响等重要问题。

This award is for the acquisition of the following instrumentation for biogeoscience research: a combustion element analyzer, an automated sampler/dilutor upgrade for an existing flow injection analyzer, and a water purification system. These instruments will directly support a variety of ecosystem studies at St. Olaf and at the same time expand opportunities for research training of undergraduates in the biogeosciences and ecology in formal courses and independent research. The broad goal of the research is to link aquatic and terrestrial ecosystems through element analysis. Acquisition of the combustion element analyzer will allow for analysis of C/N ratios of sediment organic matter, helping to distinguish terrestrial vs. aquatic sources. The element analyzer in combination with the upgraded automated sampler/dilutor will allow for continued work in Minnesota and Manitoba and expansion of this work to include sediments collected in western Mongolia. A second set of projects will focus on integrating the theory on food web structure, nutrient spiraling and ecological stoichiometry in stream ecosystems of northern California. Ecologists have long been interested in the influence of communities of organisms on fluxes of C, N, and P. Ecological stoichiometry theory provides a framework for the study of nutrient fluxes through food webs and the influence of food web structure on transport and retention of multiple nutrients. This research requires the ability to measure C, N, and P concentrations of multiple materials, including water samples and tissues of algae, plants and animals. The new instruments will significantly increase capacity to collect data necessary to explore and better understand these processes. These instruments will be used extensively by undergrads at the college, which has a long history of offering research-based classes and of fostering student-faculty research collaborations through an active summer research program with over 50 students. Both PIs have collaborated extensively with undergraduates and with researchers at other institutions across the country. The research is broadly applicable to society and is relevant to important questions such as the effects of changes in grazing practices and climate change on biogeochemistry and community ecology of stream, lake, and terrestrial ecosystems.