Collaborative Research: Quantifying the Effects of Iron and Light on the Growth of Diatoms from the Ross Sea, Antarctica

合作研究：量化铁和光对南极洲罗斯海硅藻生长的影响

• 批准号: 0739447
• 负责人: Giacomo DiTullio
• 金额: --
• 依托单位: College of Charleston
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-06-01 至 2011-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0739447&HistoricalAwards=false
• 关键词: Collaborative; Research; Quantifying; Effects; Iron

Proposal:0739685 PI Name:Sedwick, PeterProposal Title: Collaborative Research: Quantifying the Effects of Iron and Light onthe Growth of Diatoms from the Ross Sea, AntarcticaInstitution: Bermuda Institute of Ocean Sciences (BIOS), Inc.Abstract Date: 04/08/08Intellectual merit: In much of the Southern Ocean, iron and irradiance are thought toexert major controls on the timing and location of blooms of the two major phytoplanktongroups, Phaeocystis antarctica and diatoms. Recent numerical modeling studies havesimulated the broad-scale features of algal biomass and species composition in thesouthern Ross Sea, by prescribing a higher iron requirement for the growth of diatomsrelative to P antarctica and by allowing higher growth rates by P. antarctica under lowirradiance. However, there are large uncertainties associated with the parameterizationsused in these models, particularly with regard to phytoplankton iron parameters, whichare typically assigned static values. Results of recent laboratory experiments withcolonial P. antarctica suggest that the iron requirement of this species can be relativelyhigh, and appears to vary strongly as a function of irradiance. In this project, theinvestigators will use laboratory experiments to quantify the iron requirements of diatomspecies that are representative of open-water, ice-edge and sea-ice environments of thesouthern Ross Sea, including Thalassiosira gracilis, Pseudo-nitzschia subcurvata,Fragilariopsis cylindrus and Navicula glaciei. The experimental data will be used to testa number of hypotheses concerning the effects of iron availability, irradiance and UV-Bexposure on growth rates, production of dimethylsulfoniopropionate and dimethylsulfide,cellular pigment composition, and the relative uptake of macronutrients. In addition, theinvestigators will conduct preliminary "algal competition experiments", in which thegrowth of mixed assemblages containing both diatoms and colonial Phaeocystisantarctica will be examined, as a function of iron and irradiance, with and without UV-Bexposure.Broader impacts: The research will provide quantitative information that is required toconstruct robust, mechanistically-accurate numerical models of Southern Oceanecosystems and biogeochemistry. This project also will make educational contributionsat several levels, through the direct involvement of graduate and undergraduatestudents in laboratory research, and through planned outreach activities aimed at K-12students and the general public, including lecture presentations in Bermuda and SouthCarolina, and the development of web materials in consultation with a group of K-12science teachers.

提案：0739685 PI姓名：Sedwick，Peter提案标题：合作研究：量化铁和光对罗斯海硅藻生长的影响，舌舌机构：百慕大海洋科学研究所（BIOS），公司摘要日期：04/08/08知识价值：在南大洋的大部分地区，铁和辐照度被认为对两个主要植物群落的开花时间和位置起着主要的控制作用，南极棕囊藻和硅藻。最近的数值模拟研究已经模拟了东南罗斯海的藻类生物量和物种组成的大尺度特征，通过规定相对于P. anaitica的藻类生长需要更高的铁，并允许P. anaitica在低辐照下具有更高的生长速率。然而，有很大的不确定性与这些模型中使用的parameterizationsused，特别是关于浮游植物铁参数，这是典型的静态值。最近的实验室实验结果与殖民P. anastritica表明，该物种的铁的需求可以相对较高，并出现强烈的变化作为一个功能的辐照度。在本项目中，研究人员将利用实验室实验来量化罗斯海开放水域、冰缘和海冰环境中代表性的物种的铁需求，包括纤细海链藻、拟菱形藻、柱状脆杆藻和冰川舟形藻。实验数据将被用来测试一些假设的影响，铁的可用性，辐照度和UV-B暴露的增长率，生产的二甲基磺基丙酸和二甲基硫，细胞色素的组成，和相对吸收的常量营养素。此外，研究人员还将进行初步的“藻类竞争实验”，在实验中，将检查含有硅藻和群体棕囊藻的混合组合的生长，作为铁和辐照度的函数，有和没有UV-B暴露。更广泛的影响：这项研究将提供定量信息，这是建立南大洋生态系统和海洋地球化学的强大的，机械精确的数值模型所需的。该项目还将通过研究生和本科生直接参与实验室研究，并通过针对K-12学生和公众的计划外展活动，包括在百慕大和南卡罗来纳州的讲座，以及与K-12科学教师协商编写网络材料，在多个层面上做出教育贡献。