EAR-PF: Linking lakes to the landscape: mechanisms that control terrestrial subsidies to pelagic food webs

EAR-PF：将湖泊与景观联系起来：控制对远洋食物网的陆地补贴的机制

• 批准号: 1249769
• 负责人: Steven Sadro
• 金额: $ 17万
• 依托单位: Sadro Steven
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-11-01 至 2015-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1249769&HistoricalAwards=false
• 关键词: EAR; PF; Linking; lakes; landscape

Dr. Steven Sadro has been awarded an NSF Earth Sciences Postdoctoral Fellowship to implement a research and education program at the University of California, Riverside. He will use comparative and experimental approaches to investigate the extent to which variability in the concentration and composition of terrigenous inputs to lakes affects the transfer of terrestrial carbon into pelagic food webs. Terrestrial ecosystems export a considerable amount of organic matter into lakes, but the degree to which such material supports pelagic food webs is debated, and the environmental controls of such subsidies are poorly understood. In this study, the natural abundance of carbon (13C and ∆14C), nitrogen (15N), and hydrogen (2H) isotopes will be used to determine terrestrial contributions to aquatic food webs. Seasonal and spatial driven variation in the quantity and quality of terrestrial inputs will be used along with experimental manipulations to illustrate mechanisms of control on carbon transfers to pelagic organisms. These studies will be carried out in high-elevation lakes, which have consistent spatiotemporal patterns in dissolved organic matter composition driven by elevation and snowmelt dynamics, making them ideal natural laboratories for ecosystem studies of carbon flow. Lakes are natural repositories of terrestrial organic matter. The extent to which this material is decomposed, stored, or biologically cycled within lakes has important implications for energy flow, food web structure, and ultimately, the amount of carbon that is exported or released back into the atmosphere as carbon dioxide. However, evidence that terrestrial carbon is incorporated into aquatic food webs remains controversial. By characterizing the mechanisms that control the flow of terrestrial carbon in aquatic food webs, this research will illustrate linkages between organisms and help refine food web models for aquatic systems. Furthermore, high-elevation ecosystems are sensitive to the effects of climate warming; understanding carbon cycling in these systems, in particular, is a critical first step in predicting how ongoing changes in soil, vegetation, and hydrological dynamics will affect aquatic ecosystems. Dr. Sadro will directly incorporate undergraduates in both field and laboratory aspects of this research. He will assist in developing and leading a university field aquatic ecosystem science course taught at the Sierra Nevada Aquatic Research Laboratory facilities, a UC Reserve located in the eastern Sierra. Dr. Sadro will also contribute to the development of a watershed education curriculum serving under-represented secondary school students within the western Sierra Nevada Woodlake Union High School near Visalia, California.

史蒂文·萨德罗博士获得了美国国家科学基金会地球科学博士后奖学金，以在加州大学河滨分校实施研究和教育项目。他将使用比较和实验方法来研究湖泊陆源输入浓度和成分的变化在多大程度上影响陆地碳向中上层食物网的转移。陆地生态系统向湖泊输出大量有机物质，但这些物质对中上层食物网的支持程度存在争议，而且对此类补贴的环境控制知之甚少。在这项研究中，碳（13C 和 14C）、氮（15N）和氢（2H）同位素的自然丰度将用于确定陆地对水生食物网的贡献。陆地输入数量和质量的季节和空间驱动变化将与实验操作一起使用，以说明控制碳转移到远洋生物的机制。这些研究将在高海拔湖泊中进行，这些湖泊在海拔和融雪动态驱动下，溶解有机物成分具有一致的时空模式，使它们成为碳流生态系统研究的理想自然实验室。湖泊是陆地有机质的天然宝库。这种物质在湖泊中分解、储存或生物循环的程度对能量流、食物网结构以及最终以二氧化碳的形式输出或释放回大气中的碳量具有重要影响。然而，陆地碳纳入水生食物网的证据仍然存在争议。通过表征控制水生食物网中陆地碳流动的机制，这项研究将阐明生物体之间的联系，并帮助完善水生系统的食物网模型。此外，高海拔生态系统对气候变暖的影响很敏感；尤其是了解这些系统中的碳循环，是预测土壤、植被和水文动态的持续变化将如何影响水生生态系统的关键的第一步。萨德罗博士将直接让本科生参与这项研究的现场和实验室方面。他将协助开发和领导大学现场水生生态系统科学课程，该课程在内华达山脉水生研究实验室设施（位于东部山脉的加州大学保护区）教授。萨德罗博士还将致力于开发分水岭教育课程，为加利福尼亚州维塞利亚附近的内华达山脉西部伍德莱克联合高中的代表性不足的中学生提供服务。