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.

在众多繁殖养分中的基本和持久性，在沿海海洋系统中支持生态系统的生态系统，硝酸盐源自上升（=新的氮）和沿海水的铵盐再生的硝酸盐。 。沿着海洋的岩石沿岸的微生物过程通常用作替代品的生产率，我们对再生的动力学及其对较大尺度的生产力的潜在贡献。 ，加利福尼亚州的Mytilus，藻类起泡性，稳定的同位素特征和微生物遗传学，这些动物的质量强大，并提出了重要的次要次要的，在该项目中，与动物相对贡献。在贻贝的梯度中，它们将氮和氧气的氧气量为落基岩的氮气供应，而氮则添加了氮。动物可能特别容易受到变化的热环境的影响，有毒藻类在近一年的沿海氮酸化中开花。在高质量期刊中，对沿海地区的影响，教育活动将继续进行，该提议将资助两个研究生和两个地下研究。与Makah博物馆董事会和Makah高等教育委员会一起，将Makah的学生确定为Teach's Teach's Teach's Teach Broady在各自的校园中。