Collaborative Resarch: Terrestrial Support of Lake Food Webs: A Multi-Isotope Approach

合作研究：湖泊食物网的陆地支持：多同位素方法

• 批准号: 0917858
• 负责人: Stephen Carpenter
• 金额: $ 51.94万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0917858&HistoricalAwards=false
• 关键词: Collaborative; Resarch; Terrestrial; Support; Lake

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The support of animals in ecosystems ultimately comes from two sources: primary production within an ecosystem (e.g. newly grown plant material) or primary production imported from other ecosystems (e.g. inputs of terrestrial material to an aquatic system). In lakes, it is well known that external inputs are large compared to internal primary production, but how these materials support lake food webs is less well documented. Deuterium is a stable isotope of hydrogen and deuterium content of terrestrial and aquatic primary producers is significantly different. Carbon and nitrogen stable isotope ratios, while less well contrasted, are also helpful, when coupled with deuterium, in discriminating sources of consumer support. Thus, integrated analysis of hydrogen, carbon and nitrogen stable isotopes can distinguish the use of internal versus external primary production by lake animals and microbes. In this proposal the PIs will use measurements of the stable isotopes carbon, nitrogen, and hydrogen along with a new modeling approach to test hypotheses about variation in terrestrial subsidies of aquatic consumers and how these vary among different types of lakes. The multi-isotope approach will also be applied to a whole lake nutrient fertilization experiment to test differences in the support of benthic versus pelagic consumers by external organic matter. This research will directly measure variation in the support of consumers by external materials and contribute to understanding the drivers of variation among ecosystems in these processes. Several undergraduates and 2 graduate students will receive training through this research in ecosystem ecology, limnology, modeling, and stable isotope methodology. Results from this research will contribute directly to courses taught by the PIs. The stable isotope model to be utilized in this study is a tool that will be of interest to other researchers. The model which runs on open access software will be made available through our website along with documentation, tutorials, and test data. In addition, the PIs propose to sponsor a half-day workshop at a national meeting on modeling methods in isotopic studies. Providing a multi-isotope model approach to the larger research community will be a significant component of the Broader Impacts of this project.

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。生态系统中动物的支持最终来自两个来源：生态系统内的初级生产（例如新生长的植物材料）或从其他生态系统进口的初级生产（例如陆地材料输入水生系统）。 在湖泊中，众所周知，与内部初级生产相比，外部投入很大，但这些物质如何支持湖泊食物网的记录较少。 氘是氢的稳定同位素，陆生和水生初级生产者的氘含量有显著差异。 碳和氮的稳定同位素比率，虽然没有很好的对比，也是有帮助的，当与氘，在区分消费者支持的来源。 因此，氢、碳和氮稳定同位素的综合分析可以区分湖泊动物和微生物对内部初级生产和外部初级生产的使用。 在这项提案中，PI将使用稳定同位素碳，氮和氢的测量沿着一种新的建模方法来测试水生消费者陆地补贴变化的假设，以及这些假设在不同类型的湖泊中如何变化。 多同位素方法还将应用于全湖养分施肥实验，以测试外部有机物对底栖消费者和浮游消费者的支持差异。 这项研究将直接测量外部材料对消费者支持的变化，并有助于了解这些过程中生态系统之间变化的驱动因素。 几名本科生和2名研究生将通过这项研究在生态系统生态学，湖沼学，建模和稳定同位素方法学方面接受培训。 这项研究的结果将直接有助于PI教授的课程。本研究中使用的稳定同位素模型是其他研究人员感兴趣的工具。 运行在开放获取软件上的模型将通过我们的网站沿着文档、教程和测试数据提供。 此外，研究所提议在一次关于同位素研究建模方法的全国会议上主办一次为期半天的讲习班。 向更大的研究界提供多同位素模型方法将是该项目更广泛影响的重要组成部分。