Collaborative Research: Global biodiversity and functioning of eelgrass ecosystems

概述：本研究将产生第二代全球合作研究项目，即Zostera实验网络（ZEN），以量化环境强迫，生物多样性和食物网扰动对大叶藻（Zostera marina）床的结构和功能的相互作用影响，大叶藻（Zostera marina）床是全球重要但受到威胁的沿海生态系统的基础。合作伙伴将在14个国家的40个地点对生产者和消费者的生物量和多样性进行平行、标准化的实地抽样，并测量放牧和捕食率，以绘制全球生物多样性、各营养级生物量分布和大叶藻栖息地生态系统过程地图。合作伙伴将在核心站点的一部分进行析因实验，以表征营养负荷、捕食者损失和生物栖息地结构（大叶藻密度）在调节大叶藻生产者生长和营养过程中的相互作用。最后，在机制实验结果的指导下，全球野外数据将通过结构方程模型来检验关于气候变暖、营养负荷和生物多样性下降对大叶藻生态系统影响的具体假设。结构方程模型是一种独特的强大方法，可以解剖复杂的因果关系相互作用网络。拟议的研究将以前所未有的细节描述环境强迫、生物多样性和食物网过程如何相互作用，以调解全球范围内沿海生态系统的功能。有四个总体目标：1。量化大叶藻遗传多样性、生长和提供动物栖息地之间的联系2。量化大叶藻生境结构对消费-猎物相互作用、二次生产和营养转移的影响确定食草动物多样性对藻类控制的影响机制开发一个全球放牧和捕食强度地图，以评估大叶藻床自下而上和自上而下强迫的相对重要性。智力优势：该项目对全球生物多样性、生态系统状态变量和过程速率的综合表征在任何海洋系统中都是独一无二的。它以第一代ZEN的有希望的结果为基础，首次允许在全球范围内对自然系统中生物多样性和生态系统功能之间的联系进行严格分析。作为分析的一部分，拟议的研究将对海草生态系统中自下而上和自上而下强迫的相对重要性这一有争议的问题进行最全面的分析，这是一个对管理和保护至关重要的问题。更广泛的影响：海草及其提供的许多生态系统服务在全球范围内正在减少。该项目关于更高营养水平和食物网相互作用的数据将为世界各地主要关注海草和水质的许多监测项目提供有价值的和逾期的补充，并最终可用于参数化和测试受威胁的海草生态系统模型，其分辨率比以前可能的更高。Zostera实验网络（ZEN）的成功是由第二代合作伙伴（ZEN 2）的延续和招募几乎相同数量的新合作伙伴加入这一全球合作证明的。这项研究将巩固和扩大这一网络，使参与地点的数量增加一倍以上，与欧盟和日本的平行努力合作，并在弗吉尼亚海岸LTER地点整合世界上最大和最成功的海草恢复项目。ZEN 2还将为至少15名本科生实习生，几名研究生和一名博士后学者提供强化培训和国际研究经验，推进全球海洋生态学比较实验研究的创新模式，并产生一个全面的数据库和分析框架，这将对全球保护和管理受威胁的海草系统的努力具有宝贵的价值。

Overview: This research will produce the second generation of a global collaborative research project, the Zostera Experimental Network (ZEN) to quantify the interacting influences of environmental forcing, biodiversity, and food-web perturbations on structure and functioning of eelgrass (Zostera marina) beds, the foundation of important but threatened coastal ecosystems worldwide. Partners at 40 sites in 14 countries will conduct parallel, standardized field sampling of producer and consumer biomass and diversity, and measure grazing and predation rates, to produce a global map of biodiversity, biomass distribution among trophic levels, and ecosystem processes in eelgrass habitats. Partners at a subset of core sites will conduct factorial experiments to characterize the interaction of nutrient loading, predator loss, and biogenic habitat structure (eelgrass density) in mediating producer growth and trophic processes in eelgrass. Finally, guided by the results from mechanistic experiments, the global field data will be used to test specific hypotheses about impacts of climate warming, nutrient loading, and declining biodiversity on eelgrass ecosystems via structural equation modeling, a uniquely powerful approach to dissecting complex interacting networks of causality. The proposed research will characterize in unprecedented detail how environmental forcing, biodiversity, and food-web processes interact to mediate functioning of a coastal ecosystem on a global scale. There are four general objectives: 1. Quantify linkages between eelgrass genetic diversity, growth, and provision of animal habitat 2. Quantify the influence of eelgrass habitat structure on consumer-prey interactions, secondary production, and trophic transfer 3. Identify mechanisms for the influence of grazer diversity on algal control 4. Develop a global map of grazing and predation intensity to assess the relative importance of bottom-up and top-down forcing in eelgrass beds Intellectual Merit: This program's integrated characterization of biodiversity, ecosystem state variables, and process rates across the globe is arguably unique in any marine system. It builds on promising results from the first generation of ZEN to allow for the first time a rigorous analysis of links between biodiversity and ecosystem functioning in a natural system on a global scale. As part of this analysis, the proposed research will provide the most comprehensive analysis yet of the controversial question of the relative importance of bottom-up and top-down forcing in seagrass ecosystems, an issue of fundamental importance to management and conservation. Broader Impacts: Seagrasses and the many ecosystem services they provide are declining worldwide. This project's data on higher trophic levels and food-web interactions will provide a valuable and overdue complement to the many monitoring programs around the world that focus primarily on seagrasses and water quality, and will ultimately be made available to parameterize and test models of threatened seagrass ecosystems at a higher level of resolution ecological reality than previously possible. The success of the Zostera Experimental Network (ZEN) is evidenced by the continuation of all but one partner in the second generation (ZEN 2), and recruitment of nearly the same number of new partners to this global collaboration. This research will solidify and expand this network by more than doubling the number of participating sites, collaborating with parallel European Union and Japanese efforts, and integrating the world's largest and most successful seagrass restoration project at the Virginia Coast LTER site. ZEN 2 will also provide intensive training and international research experiences for at least 15 undergraduate interns, several graduate students, and a Postdoctoral Scholar, advance an innovative model of comparative-experimental research in global marine ecology, and produce a comprehensive database and analytical framework that will be invaluable to global efforts at conservation and management of threatened seagrass systems.