Collaborative Research: The Role of Regenerated Nitrogen for Rocky Shore Productivity

合作研究：再生氮对岩岸生产力的作用

• 批准号: 0928015
• 负责人: David Post
• 金额: $ 14.47万
• 依托单位: Yale University
• 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=0928015&HistoricalAwards=false
• 关键词: Collaborative; Research; Role; Regenerated; Nitrogen

A fundamental and persistent question in a multitude of ecosystems is the extent to which new versus regenerated nutrients support ecosystem productivity. In coastal marine systems, nitrate derived from upwelling (= new nitrogen) and ammonium regeneration in coastal waters and sediments (= regenerated nitrogen) are major nitrogen sources that fuel coastal ocean productivity. Because inorganic nitrogen availability clearly regulates production in a large number of areas, understanding nitrogen supply is essential. In open coast regions away from river mouths, nitrate inputs are determined by large-scale physical processes promoting upwelling of deep, nutrient-rich water including wind direction and intensity. In contrast, regenerated nitrogen (mainly ammonium) is generally the result of local animal and microbial processes. Along marine rocky shores, where upwelling is typically used as a proxy for productivity, we know very little about the dynamics of regenerated nutrients and their potential contribution to productivity at larger scales; only upwelling is typically used as a proxy for productivity. Associations of the abundant California mussel, Mytilus californianus, with water nutrients, algal productivity, stable isotope signatures, and microbial genetics indicate potentially strong regeneration of nitrogen by these animals and suggest an important secondary role of nitrifying microbes affiliated with these animals. In this project, the investigators will quantify the relative contribution of regenerated nitrogen on rocky shores through censuses and experiments across a gradient of mussel abundance. They will use stable nitrogen and oxygen isotopes of ammonium, nitrite, and nitrate to disentangle the contribution of different biological processes versus upwelling to the nitrogen supply and uptake of rocky shore regions. This includes both natural abundance and tracer addition studies. Broader Impacts. Regenerated nitrogen supply, as opposed to new nitrogen via upwelling, is a local process dependent upon an intact animal community. However, mussels and other nearshore animals may be particularly vulnerable to a changing thermal environment, toxic algal blooms, and ocean acidification. Given the dramatic changes to the coastal nitrogen cycle in recent years, and potential changes to currents, upwelling, ocean chemistry, and El Niño frequencies portended by global changes to our climate, we to know the relative effect of local versus larger scale oceanic events on the nitrogen cycle. The proposed work links biological interactions in situ with its implications for coastal productivity. In addition to expected publications in high quality journals, educational activities will continue to focus on graduate and undergraduate education and mentoring. The proposal will fund two graduate students and two undergraduates per year. The PI's will work closely with government (Olympic Marine National Sanctuary) and tribal (Makah Tribe) representatives to communicate this research. We will also work with Makah Museum Board of Trustees and the Makah Higher Education Committee to identify Makah students as research assistants. All three PI's teach broadly across their respective campuses, instructing almost every type of undergraduate major.

在许多生态系统中，一个基本和持久的问题是新的和再生营养支持生态系统生产力的程度。在沿海海洋系统中，沿海水域和沉积物中的上升流（=新的氮）和铵再生衍生的硝酸盐是促进沿海海洋生产率的主要氮源。由于无机氮的可用性清楚地调节了许多领域的产量，因此了解氮供应至关重要。在远离河口的开放海岸地区，硝酸盐输入是由大规模的物理过程确定的，促进了深，营养丰富的水的上升，包括风向和强度。相反，再生的氮（主要是铵）通常是局部动物和微生物过程的结果。沿着海洋岩石海岸（Prossivitivity）通常被用作生产力的代理，我们对再生营养素的动态及其对生产力的潜在贡献较大，我们对较大尺度的生产力的贡献知之甚少。通常仅将上升作为生产力的代理。丰富的加利福尼亚贻贝，加利福尼亚州的杂种，藻类养分，藻类生产力，稳定同位素特征和微生物遗传学的关联表明，这些动物可能会对氮对氮的强劲再生，并提出了与这些动物相关的硝化微生物的重要次要作用。在该项目中，研究人员将通过人口普查和实验跨肌肉丰度梯度来量化再生氮对岩石海岸的相对贡献。他们将使用铵，亚硝酸盐和硝酸盐的稳定氮和氧同位素来解散不同生物学过程的贡献，而不是上升对氮供应和岩石岸边的吸收。这既包括自然丰度和示踪剂添加研究。更广泛的影响。再生的氮供应与通过上升流相反，与新的氮相反，是一个依赖于完整动物群落的当地过程。但是，贻贝和其他近岸动物可能特别容易受到不断变化的热环境，有毒的藻类血液和海洋酸化的影响。鉴于近年来沿海氮周期发生了巨大变化，以及电流，上升，海洋化学和厄尔尼诺尼诺频率的潜在变化因全球气候变化而赋予的厄尔尼诺尼诺频率，我们知道局部与较大规模的海洋事件对氮气周期的相对效果。拟议的工作将生物学相互作用与对沿海生产的影响联系起来。除了在高质量期刊上的预期出版物外，教育活动还将继续关注研究生和本科教育和心理。该提案将为两名研究生和两名本科生提供资金。 PI将与代表这项研究的政府（奥林匹克海洋国家保护区）和部落（Makah Tribe）紧密合作。我们还将与Makah博物馆董事会和Makah高等教育委员会合作，以确定Makah学生为研究助理。这三个PI在各自的校园中都广泛地教学，指导几乎所有类型的本科专业。