Grazer Diversity, Foodweb Architecture, and Ecosystem Function in Eelgrass Beds

该项目将采用一个综合方案的围隔和现场实验，以确定影响的放牧动物多样性的营养过程（植物生产力和功能群组成，次级生产，营养转移）在床的大叶藻（Zostera niarina），一个重要的生态工程在整个北方沿海地区。植被河口系统是特别适合于解决之间的联系，因为有充分的证据表明，在这些系统中的植物组合和捕食者生产的影响，和他们相对较快的反应，以操纵食草动物多样性和生态系统过程。研究人员以前的研究表明，小型无脊椎食草动物在维持这种和其他植被底栖生态系统的正常结构和功能方面可以发挥关键作用。然而，人们对食草动物在多层次海草食物网中的重要性仍然知之甚少。因此，本研究有三个目的：1）探讨放牧和资源限制对荻草群落结构和功能的相对重要性，以及食草动物多样性在其中的调节作用：2）以荻草群落为模型系统，探讨食草动物多样性对营养级级联转换的影响; 3）通过比较不同年份和不同季节的生产和营养过程的差异，检验生物多样性与生态系统稳定性之间的假设联系。

This project will employ an integrated program of mesocosm and field experiments to determine the influence of grazer diversity on trophic processes (plant productivity and functional group composition, secondary production, and trophic transfer) in beds of eelgrass (Zostera niarina), an important ecological engineer in coastal regions throughout the northern hemisphere. Vegetated estuarine systems are particularly suited to addressing links between grazer diversity and ecosystem processes because of the well documented impacts of grazers on both plant assemblages and predator production in these systems, and their relatively rapid responses to manipulation. The investigator's previous research demonstrated that small invertebrate grazers can be pivotal in maintaining normal structure and function in this and other vegetated benthic ecosystems. Yet the importance of grazers in the context of the multi-level seagrass food webs remains poorly understood. Accordingly, the study three goals: 1) to test the relative importance of grazing and resource limitation to structure and function of eelgrass communities, and the role of grazer diversity in mediating them; 2) to test the impact of grazer diversity on penetrance of the trophic cascade, using the eelgrass community as a model system; and 3) to test the hypothesized link between biodiversity and ecosystem stability by comparing variance in production and trophic processes across years and seasons as a function of grazer diversity.