Collaborative Research: Ecosystem Structure, Biogeochemical Fluxes and Vulnerability to Climate Change Perturbations

合作研究：生态系统结构、生物地球化学通量和气候变化扰动的脆弱性

• 批准号: 0097251
• 负责人: Michael Roman
• 金额: $ 13.82万
• 依托单位: University of Maryland Center for Environmental Sciences
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-01 至 2005-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0097251&HistoricalAwards=false
• 关键词: Collaborative; Research; Ecosystem; Structure; Biogeochemical

This project is part of the U.S. JGOFS Synthesis and Modeling Project (SMP) aimed at the SMP objective of understanding Mechanistic Controls of Local Carbon Balances, specifically the role of food web structure in controlling particle flux, particle export, nutrient regeneration and DOC production in oceanic systems. The collaborators will use data generated from the JGOFS process studies to consolidate field measurements into formal, quantitative descriptions of size and function-based food web groups and the material flows between them. They will use inverse techniques to infer unknown (unmeasured) material flows in the food webs. Finally they will use the trophic networks derived to test the stability of the plankton-biogeochemical ecosystem following potential perturbations to simulate changes due to ocean warming or increased stratification. Scientific reviews strongly support the assertion that understanding how the biological pump operates requires detailed knowledge of the relationships between food web structure, productivity, new production and biological fluxes. The amount of material leaving the surface layer is usually dependent on how it is partitioned among the plankton community. In an idealized plankton community, most of the primary production that passes through bacterioplankton and microzooplankton is likely to be recycled in the surface layer. In contrast, a significant portion of the primary production that passes through the mesozooplankton may become part of the sinking flux of organic matter via fecal pellet production and active transport below the euphotic zone due to vertical migration. Although many of the relevant processes were measured in JGOFS, the resulting data have never been rigorously condensed in a series of depictions of foodwebs consistent with all the data. This food web synthesis, a collaborative effort between Hugh Ducklow, George Jackson and Mike Roman, aims to further an ecosystem-based synthesis of JGOFS results. The goal is the construction or 'recovery' of a series of solutions to foodweb networks consistent with observations from the four major US JGOFS Process Studies in the North Atlantic (NABE); the Equatorial Pacific (EQPAC); the Arabian Sea and the Southern Ocean Process Study (AESOPS -- Ross). The project is based on the assumption that improved understanding of ecosystem structure and function depends critically on knowledge of the component rate processes, or inter-compartmental exchanges. There now exists a body of formal techniques and theory for analyzing the holistic properties of such flux networks. The research plan consists of four elements: 1. Consolidate field measurements into descriptions of size and function-based food web groups and the measured flows between them. 2. Use inverse techniques to infer unknown (unmeasured) material flows in the food web. 3. Use biomass and rate information to examine stability properties and how they differ, and how characteristic flow structures generate basin scale contrasts in particle export, nutrient regeneration, and DOC production in oceanic systems. 4. From the derived stability properties, infer the vulnerability of different foodweb structures (different ocean provinces) to ocean warming and changing stratification.

该项目是美国JGOFS合成和建模项目（SMP）的一部分，旨在了解局部碳平衡的机械控制，特别是食物网结构在控制海洋系统中的颗粒通量，颗粒输出，营养再生和DOC生产中的作用。合作者将利用JGOFS过程研究产生的数据，将实地测量结果整合为对基于大小和功能的食物网群体以及它们之间的物质流的正式、定量描述。他们将使用逆向技术来推断食物网中未知（未测量）的物质流。最后，他们将使用衍生的营养网络来测试潜在扰动后的南极洲地球化学生态系统的稳定性，以模拟由于海洋变暖或分层增加而引起的变化。科学评论强烈支持这样一种说法，即要了解生物泵的运作方式，就需要详细了解食物网结构、生产力、新产品和生物通量之间的关系。离开表层的物质的数量通常取决于它在浮游生物群落中的分配方式。在理想的浮游生物群落中，通过浮游细菌和微型浮游动物的大部分初级生产力可能在表层再循环。相比之下，初级生产的一个显着的部分，通过浮游动物可能成为下沉通量的有机物通过粪粒生产和主动运输下透光层由于垂直迁移。虽然许多相关的过程都是在JGOFS中测量的，但由此产生的数据从未被严格浓缩在一系列与所有数据一致的食物网分析中。 这份食物网综合报告是休·达克洛、乔治、杰克逊和迈克·罗曼共同努力的结果，旨在进一步对JGOFS结果进行基于生态系统的综合。其目标是建立或“恢复”一系列与美国联合全球海洋观测系统四个主要进程的观测结果相一致的食物网网络解决方案：北大西洋进程研究;赤道太平洋进程研究;阿拉伯海和南大洋进程研究。该项目是基于这样的假设，即提高对生态系统结构和功能的认识，关键取决于对组分速率过程或室间交换的了解。现在有一个正式的技术和理论分析的整体性质，这样的通量网络的身体。研究计划包括四个要素：1。将实地测量结果整合到对基于大小和功能的食物网组以及它们之间的测量流量的描述中。2.使用逆向技术来推断食物网中未知（未测量）的物质流。3.使用生物量和速率信息来研究稳定性特性及其差异，以及特征流结构如何在海洋系统中产生颗粒输出，营养物再生和DOC生产的流域尺度对比。4.从衍生的稳定性属性，推断不同的食物网结构（不同的海洋省份）的脆弱性，海洋变暖和不断变化的分层。