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

鳗草床的食草多样性、食物网结构和生态系统功能

• 批准号: 0099226
• 负责人: J. Emmett Duffy
• 金额: $ 35.2万
• 依托单位: College of William & Mary Virginia Institute of Marine Science
• 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: 2001-03-01 至 2004-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0099226&HistoricalAwards=false
• 关键词: Grazer; Diversity; Foodweb; Architecture; Ecosystem

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.

本项目将采用生态系统和野外试验相结合的综合方案，确定食草动物多样性对大叶藻（Zostera niarina）床的营养过程（植物生产力和功能群组成、二次生产和营养转移）的影响。大叶藻是北半球沿海地区重要的生态工程。有植被的河口系统特别适合于解决食草动物多样性与生态系统过程之间的联系，因为有充分记录的食草动物对这些系统中的植物组合和捕食者生产的影响，以及它们对操纵的相对快速的反应。研究者之前的研究表明，小型无脊椎食草动物在维持这个和其他植被底栖生态系统的正常结构和功能方面起着关键作用。然而，在多层次海草食物网的背景下，食草动物的重要性仍然知之甚少。因此，本研究的三个目标是：1)考察放牧和资源限制对大叶藻群落结构和功能的相对重要性，以及放牧者多样性在大叶藻群落结构和功能中的调节作用；2)以大叶藻群落为模型系统，考察放牧动物多样性对营养级联外显率的影响；3)通过比较不同年份和季节的生产和营养过程的变化作为食草动物多样性的函数来检验生物多样性与生态系统稳定性之间的假设联系。