Coupling Consumer-Resource Interactions and Nutrient Spiraling in a Stream Network

本研究的主要目的是了解河流网络位置如何影响营养循环、河流代谢和消费者-资源相互作用之间的反馈。总的问题是，生物相互作用和生物化学组成在何时何地是河流网络中营养通量的重要决定因素，对下游生态群落的影响是什么？最近关于消费者驱动的养分循环的理论表明，河流消费者（如昆虫）元素含量的变化部分是由资源可用性驱动的，部分是由特定生活史特征的出现驱动的，这些特征是为了响应不断变化的环境条件，沿着物理变量的梯度变化。消费者和资源之间化学不平衡的变化对养分流动的影响是溪流研究中令人兴奋的前沿。研究人员将在几个网络位置和藻类演替过程中检查溪流代谢、消费者-资源相互作用和生物地球化学循环之间的反馈。他们将利用这些测量来评估藻类和死亡有机物质的变化以及消费者-资源相互作用对多种营养物质通量的全系统影响，通过探索它们对营养物质吸收和再生的特定影响。该项目及其科学合作伙伴关系将为文科学生提供探索生态系统科学的新的独特机会，并获得大型研究小组的哲学和实验室设施。

The main objective of this study is to understand how stream network position influences feedbacks between nutrient cycles, stream metabolism, and consumer-resource interactions. The overall question is where and when are biotic interactions and biological chemical makeup important determinants of nutrient flux in river networks, and what are the consequences for downstream ecological communities? Recent theory addressing consumer-driven nutrient recycling suggests that shifts in elemental content of stream consumers, such as insects, are driven in part by resource availability and in part by the emergence of specific life history traits in response to changing environmental conditions along gradients of physical variables. The effects of resulting shifts in chemical imbalances between consumers and resources on nutrient fluxes is an exciting frontier in the study of streams. The investigators will examine feedbacks between stream metabolism, consumer-resource interactions and biogeochemical cycling at several network positions and during algal succession. They will use these measurements to estimate whole-system effects of changes in algal and dead organic matter and consumer-resource interactions on fluxes of multiple nutrients by exploring their specific effects on nutrient uptake and regeneration. This project and its science partnerships will provide liberal arts students with new and unique opportunities to explore ecosystem science and access to philosophies and lab facilities of large research groups.