Collaborative Proposal: MSA: Controls on coupled nitrogen and carbon cycles of watersheds across eco-regions

标题：合作提案：MSA：跨生态区流域氮碳耦合循环的控制氮是维持生命的重要营养物质。过量会导致一些问题，比如难看的藻华或鱼类无法生存的沿海死区。氮的命运与植物和土壤中碳的命运密切相关。然而，氮和碳之间的联系仍然知之甚少。特别是，从热带到北极，人们对碳和氮在不同景观中的相互作用知之甚少。这个项目将有助于更好地了解是什么控制着氮通过溪流离开流域。它将利用国家生态观测网在全国不同环境中收集的数据。这项研究很重要，因为人们通过空气污染、肥料和化粪池系统向土地添加了更多的氮。它还将有助于了解随着大气中二氧化碳的增加，环境可以吸收多少碳。该项目将产生与其他研究人员共享的新数据集。该项目团队将与学校和当地社区合作，解释陆地上发生的事情如何影响水质。研究结果将被转化为对决策者有用的东西。不同的学生群体将学习如何使用环境传感器技术。NEON收集的陆地和水生生态系统的一致输入和输出测量将用于解决首要问题：“流域碳(C)和氮(N)循环在生物群落之间耦合的紧密程度，以及这种耦合如何受到物理环境条件（气候和水文）、植被特征和过去干扰遗留的影响？”我们将测试与流域碳氮比、降水、风暴、温度和扰动作用相关的假设，使用1)正在进行的NEON传感器、人工收集和遥感测量来估计流域N输入、N输出和净生态系统C交换（NEE）， 2)陆地生态系统模型（PnET）将NEE扩展到整个流域，以及3)根据每个域的潜在解释数据分析流域净N和C通量。将使用22个NEON流域，这些流域由可涉水的溪流和NEE测量值附近定义，结合了广泛的流域特征。流域预算估计将包括对碳和氮通量和汇的不确定性的估计。科学发现将通过LTER校园项目和科学政策交流等团体转化为教育和政策相关信息。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Title: Collaborative Proposal: MSA: Controls on coupled nitrogen and carbon cycles of watersheds across eco-regionsNitrogen is a critical nutrient that supports life. Too much can cause problems such as unsightly algal blooms or coastal dead zones where fish cannot live. The fate of nitrogen is closely tied to the fate of carbon in plants and soil. However, the connection between nitrogen and carbon remains poorly understood. In particular, little is known about carbon and nitrogen interactions across different landscapes, from the tropics to the arctic. This project will help better understand what controls nitrogen leaving watersheds through streams. It will take advantage of data collected by the National Ecological Observatory Network across the nation's diverse environments. This research is important as people add more nitrogen to the land through air pollution, fertilizers, and septic systems. It will also help understand how much carbon the environment can absorb as carbon dioxide increases in the atmosphere. The project will result in new data sets that will be shared with other researchers. The project team will work with schools and local communities to explain how what happens on land affects water quality. Findings will be translated to be useful for policy makers. A diverse group of students will learn how to use environmental sensor technology. Consistent input and output measurements for terrestrial and aquatic ecosystems collected by NEON will be used to address the overarching question: "How tightly are watershed carbon (C) and nitrogen (N) cycles coupled across biomes and how is this coupling influenced by physical environmental conditions (climate and hydrology), vegetation characteristics, and legacies from past disturbance?" Hypotheses will be tested related to the role of watershed carbon to nitrogen ratios, precipitation, storminess, temperature, and disturbance using 1) ongoing NEON sensor, manually-collected, and remote sensing measurements to estimate watershed N inputs, N outputs and net ecosystem C exchange (NEE), 2) a terrestrial ecosystem model (PnET) to scale NEE to the entire watershed draining to streams, and 3) analysis of watershed net N and C fluxes against potential explanatory data for each domain. Twenty-two NEON watersheds defined by wadeable streams and proximity of NEE measurements will be used, incorporating a wide range of watershed characteristics. Watershed budget estimates will include estimates of uncertainty in both C and N fluxes and sinks. Scientific findings will be translated into education and policy relevant information with groups such as LTER Schoolyard program and the Science Policy Exchange.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.