Variation in the Strength of Cascading Trophic Interactions Across a Riverscape

河流景观中级联营养相互作用强度的变化

• 批准号: 0516035
• 负责人: Barbara Peckarsky
• 金额: $ 35万
• 依托单位: Rocky Mountain Biological Laboratory
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0516035&HistoricalAwards=false
• 关键词: Variation; Strength; Cascading; Trophic; Interactions

Natural flow regimes of rivers are undergoing considerable modification due to global change and human use of water. This research will contribute to understanding how natural variation in flow influences the function of river ecosystems. The grazing of algae by insect larvae is a fundamentally important interaction in rivers that is affected by the flow regime. In some streams large amounts of algae result from 'trophic cascades' whereby predators like trout suppress grazing leading to increases in algae. In other streams insect grazers are able to keep algae in check. Extreme events like floods and droughts can influence grazer-algal interactions by affecting the abundance and type of grazers, numbers of trout, algal growth rates, and availability of nutrients. The effects of variation in flow regimes on grazer-algal interactions will be measured across a river-landscape to unravel the controls on the strength of trophic cascades. This work focuses on species interactions fundamental to many ecosystems; thus it will contribute to producing broadly applicable ecological generalities. Furthermore, the project builds on 30 years of research on streams in the East River valley near the Rocky Mountain Biological Laboratory in Western Colorado. The fate of water resources is hotly debated in Western Colorado, like many other areas around the world. By advancing understanding of the effects of natural variation in flow regimes on river inhabitants, the research will provide knowledge valuable for the management of rivers with human-induced changes to river flow.

由于全球变化和人类用水，河流的自然流态正在经历相当大的改变。 这项研究将有助于了解流量的自然变化如何影响河流生态系统的功能。昆虫幼虫对藻类的放牧是河流中受水流影响的一种极其重要的相互作用。在一些溪流中，大量藻类是由“营养级联”产生的，鳟鱼等捕食者抑制放牧，导致藻类数量增加。在其他溪流中，食草昆虫能够控制藻类。洪水和干旱等极端事件会影响食草动物的丰度和类型、鳟鱼的数量、藻类生长速度和营养物质的可用性，从而影响食草动物与藻类的相互作用。 将在整个河流景观中测量水流变化对食草动物-藻类相互作用的影响，以揭示对营养级联强度的控制。这项工作的重点是对许多生态系统至关重要的物种相互作用；因此，它将有助于产生广泛适用的生态一般性。此外，该项目建立在对科罗拉多州西部落基山生物实验室附近东河谷溪流 30 年的研究基础上。 与世界上许多其他地区一样，水资源的命运在科罗拉多州西部引起了激烈的争论。 通过加深对水流自然变化对河流居民影响的理解，该研究将为人为引起的河流流量变化的河流管理提供有价值的知识。