CAREER: Control Points on nutrient cycling in hypereutrophic lakes

由于湖泊的面积很小，它们是景观中捕获、转化、排放和储存碳的重要地方。人类在流域内的活动正在导致许多湖泊和水库营养过度丰富。这就是所谓的富营养化。过度浓缩会导致生态系统中的各种问题，包括改变碳循环。虽然在了解控制湖泊和水库中碳循环的过程方面取得了实质性进展，但人们对这些过程如何在营养浓度极高的水体中运行知之甚少，这种情况正变得越来越普遍。这项研究旨在确定极端营养负荷下湖泊和水库碳循环的关键控制因素。这将有助于预测这些生态系统将如何应对未来的环境压力。除碳循环外，湖泊和水库还提供受到富营养化威胁的重要生态系统服务。管理淡水资源以保护生态系统服务对社会福祉至关重要。然而，有关淡水资源的决策需要在地方一级工作的受过教育的水管家。该项目将为当地水管理人员提供水生生态系统管理方面的广泛培训，使其社区能够就湖泊和流域管理作出知情的、以数据为导向的决策。为了确定碳循环的重要驱动力何时何地在营养极度丰富的湖泊中运行，将在高营养湖泊部署高频传感器，以捕捉全年的碳循环动态。其中一个重点研究湖位于爱荷华州立大学校园内。直播数据和监控活动将纳入校园内的教育机会。另外20个湖泊年的高频数据将通过湖泊管理教育和当地水管家志愿者培训计划收集。所有基于传感器的测量将与频率较低的天气采样相结合，以量化进入湖泊和循环的碳池和养殖池。这些时间序列将用于量化控制碳循环动力学的有氧、厌氧和物理运输过程，并确定碳循环速率的环境驱动因素。这些信息与130个湖泊的长期水质监测数据相结合，将被用来估计区域范围内的水生碳循环率。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Lakes are important places in the landscape for capturing, transforming, emitting, and storing carbon given their small surface area. Human activities in watersheds are causing many lakes and reservoirs to become over-enriched in nutrients. This is called hypereutrophication. Over-enrichment can cause a variety of problems in ecosystems, including changes in carbon cycling. While substantial progress has been made in understanding the processes that control carbon cycling in lakes and reservoirs, relatively little is known about how those processes operate in water bodies with extremely high nutrient concentrations, a condition which is becoming increasingly common. This research is aimed at identifying the key controls on carbon cycling in lakes and reservoirs under extreme nutrient loading. This will help predict how these ecosystems will respond to future environmental stresses. In addition to carbon cycling, lakes and reservoirs also provide important ecosystem services that are threatened by eutrophication. Managing freshwater resources to protect ecosystem services is vital for societal well-being. Yet, decisions about freshwater resources require educated water stewards working at the local level. This project will provide extensive training in aquatic ecosystem management to local water stewards, empowering their communities to make informed, data-driven decisions about lake and watershed management. In order to identify when and where the important drivers of carbon cycling are operating in lakes under extreme nutrient enrichment, high frequency sensors will be deployed in high-nutrient lakes to capture carbon cycling dynamics throughout the entire year. One of the focal study lakes is located on the Iowa State University campus. The live-streaming data and monitoring activities will be incorporated into educational opportunities across campus. An additional 20 lake-years of high frequency data will be collected through a lake management education and volunteer training program for local water stewards. All of the sensor-based measurements will be paired with less frequent synoptic sampling to quantify the pools of carbon and nutrients entering and cycling in the lakes. These time series will be used to quantify the aerobic, anaerobic, and physical transport processes controlling carbon cycling dynamics and to determine the environmental drivers of carbon cycling rates. This information, combined with long term water quality monitoring data from 130 lakes embedded in a nutrient-rich landscape, will be used to estimate aquatic carbon cycling rates at a regional scale.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.