Grazing and Dynamics of Grazer Populations in a Temperate Fjord

温带峡湾的放牧和食草动物种群动态

• 批准号: 9202657
• 负责人: Bruce Frost
• 金额: $ 8.5万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-05-01 至 1994-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9202657&HistoricalAwards=false
• 关键词: Grazing; Dynamics; Grazer; Populations; Temperate

In Dabob Bay (Washington), a temperate fjord, the annual cycles of phytoplankton standing stock and production rate exhibit spectacular increases (phytoplankton blooms) in spring and autumn, indicating lack of control by grazer populations. Yet virtually all organic matter produced by the phytoplankton during blooms is ultimately consumed by grazers. Moreover, a major fraction of the grazing (about 67% on an annual basis) appears to be due to macrozooplankton suspension-feeders, with microzooplankton being secondary grazers. A conceptual model of grazing in Dabob Bay was developed, hypothesizing the identities of the macro- and microzooplankton grazers and postulating mechanisms for the approximate annual balance between phytoplankton growth and grazing. A field test of the conceptual model was developed and carried out on three extended research cruises to Dabob Bay in 1990-91. This project will complete the analysis of samples and data, and produce a synthesis. By direct measuerements this study will provide quanitative assessment of mechanisms and rates of processes governing the dynamics of phytoplankton production and its fate in a highly productive coastal pelagic ecosystem.

在Dabob湾（华盛顿），一个温带峡湾，浮游植物的年循环储量和产量在春季和秋季表现出惊人的增长（浮游植物大量繁殖），表明食草动物种群缺乏控制。然而，几乎所有浮游植物在繁殖期间产生的有机物质最终都被食草动物消耗掉了。此外，放牧的主要部分（每年约67%）似乎是由于大型浮游动物的悬浮食性，而小型浮游动物是次级食性。建立了Dabob湾放牧的概念模型，假设了大型和小型浮游动物食草者的身份，并假设了浮游植物生长与放牧之间近似年度平衡的机制。1990-91年期间，对概念模型进行了实地试验，并在达博布湾进行了三次延长的研究巡航。这个项目将完成样品和数据的分析，并产生一个综合。通过直接测量，本研究将对一个高产的沿海远洋生态系统中浮游植物生产动态及其命运的控制过程的机制和速率进行定量评估。