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

该项目是美国JGOFS综合与建模项目（SMP）的一部分，旨在了解局部碳平衡的机制控制，特别是食物网结构在控制海洋系统中颗粒通量、颗粒输出、养分再生和DOC产生中的作用。合作者将使用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组及其之间的物质流动的正式、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）的物质流动。最后，他们将使用衍生的营养网络来测试浮游生物-生物地球化学生态系统在潜在扰动后的稳定性，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的主张，即理解生物泵如何运作需要对食物网结构、生产力、新产量和生物通量之间的关系有详细的了解。离开表层的物质的数量通常取决于它在浮游生物群落中是如何分配的。在一个理想的浮游生物群落中，大部分通过浮游细菌和微型浮游动物的初级产品很可能在表层再循环。相比之下，通过中浮游动物的相当一部分初级生产可能成为有机物下沉通量的一部分，通过粪便颗粒生产和垂直迁移在光带以下的主动运输。虽然在JGOFS中测量了许多相关过程，但所得数据从未严格浓缩为与所有数据一致的一系列食物网描述。由Hugh Ducklow、George Jackson和Mike Roman合作完成的食物网综合，旨在进一步以生态系统为基础综合JGOFS结果。目标是构建或“恢复”与美国四大JGOFS北大西洋过程研究（NABE）观察结果一致的一系列食物网解决方案；赤道太平洋；阿拉伯海和南大洋过程研究（AESOPS - Ross）。该项目基于这样的假设：对生态系统结构和功能的进一步了解主要取决于对组分速率过程或区间交换的了解。现在已经有了一套形式化的技术和理论来分析这种通量网络的整体特性。研究计划包括四个要素：1。将现场测量结果整合到基于大小和功能的食物网组的描述中，以及它们之间的测量流。2. 使用反向技术来推断食物网中未知（未测量）的物质流动。3. 利用生物量和速率信息来检查稳定性特性及其差异，以及海洋系统中颗粒输出、养分再生和DOC生成的特征流结构如何产生盆地尺度的差异。4. 根据得到的稳定性特性，推断不同食物网结构（不同海洋省份）对海洋变暖和分层变化的脆弱性。

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.