Cascading Trophic Interactions in Lake Ecosystems: Effects on Bacteria and Their Consumers

湖泊生态系统中的级联营养相互作用：对细菌及其消费者的影响

• 批准号: 8805893
• 负责人: Michael Pace
• 金额: $ 19.49万
• 依托单位: New York Botanical Garden
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-08-01 至 1991-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8805893&HistoricalAwards=false
• 关键词: Cascading; Trophic; Interactions; Lake; Ecosystems

Heterotrophic microorganisms process a substantial portion of the primary production of aquatic ecosystems. This research will examine how food web interactions control microbial productivity. Whole lake experiments are being conducted at the University of Notre Dame Environmental Research Center that manipulate fish populations that in turn modify the planktonic food web. This project will study the response of the heterotrophic microbial community. The effect of planned manipulations will be to decrease zooplankton biomass and increase phytoplankton biomass and productivity. It is hypothesized that bacteria, protozoa, bacterial production, and grazing on bacteria will all increase in response to these manipulations. The enhanced microbial activity in the manipulated lakes will also lead to higher rates of total water column respiration. Measurements of the biomass, productivity, grazing by heterotrophic microbes as well as community respiration will be made to test these hypotheses at the ecosystem scale. The direct and indirect effects of the food web on heterotrophic microbes will be further examined in enclosure experiments and modeling studies. Results from this study will likely be of major significance in terms of the basic understanding of the biotic dynamics of lakes and may be applicable to new strategies for lake management.

异养微生物处理水生生态系统主要生产的很大一部分。 这项研究将研究食品网络相互作用如何控制微生物生产力。 整个湖泊的实验是在巴黎圣母院环境研究中心进行的，该研究中心操纵鱼类种群，反过来修改了浮游食品网。 该项目将研究异养微生物群落的反应。 计划的操作的效果将是减少浮游动物生物量并提高浮游植物生物量和生产力。 假设细菌，原生动物，细菌产生和对细菌放牧的响应都会增加。 操纵湖泊中的微生物活性增强也将导致总水柱呼吸的率更高。 将进行生物量，生产力，异养微生物放牧以及社区呼吸的测量，以在生态系统量表上检验这些假设。 食物网对杂营微生物的直接和间接影响将在外壳实验和建模研究中进一步研究。 这项研究的结果在对湖泊生物动力学的基本了解方面可能具有重要意义，并且可能适用于湖泊管理的新策略。