RAPID: Effects of Drying Disturbance on Energy Flux Across the Aquatic-Terrestrial Boundary: Dam Malfunction Influences Aquatic Insect Emergence Quantity and Phenology

在孵化期间从河流中冒出来的水生昆虫为许多捕食者提供了主要的能量和营养来源。水生昆虫所含的碳、氮等营养物质是陆地生态系统的重要食物补贴。然而，由于水资源的变化、污染和温度变暖，昆虫对全球范围内的减少很敏感。尽管出现了这些广泛的下降，但人们对水生昆虫的出现如何影响邻近的陆地生态系统知之甚少，因为在监测项目中，对成年水生昆虫生命阶段的研究还很不足，成年水生昆虫的生命阶段允许能量和营养物质从水生环境转移到陆地消费者。该项目研究了严重干燥干扰在调节新兴水生昆虫孵化中的作用，特别是鲑鱼，这是石蝇目中对全球变化敏感的大型水生昆虫。研究人员正在评估大坝溃坝导致的水流量急剧减少对鲑鱼密度、生物量和出现时间的影响。一名博士后学者和几名本科生研究助理正在接受培训，一项关于干旱主题的公众调查将完成，这项研究将在蒙大拿州西南部的一个当地节日上展示。公众宣传将强调水与陆地之间的紧密联系，以及新兴水生昆虫作为鱼类、鸟类和哺乳动物的营养和能量来源的重要性。该项目将通过提供关于脉冲干燥干扰对水生昆虫成虫期影响的新信息，为我们理解人为变化下水陆联系的转变作用和弹性做出革命性贡献。该研究项目调查了蒙大拿州西南部麦迪逊河上的大坝故障，导致短暂但广泛的干旱事件，与前几年相比，如何改变水生昆虫的出现。这项研究的重点生物是巨型鲑鱼，它是落基山脉西部河流中具有重要生态和文化意义的水生昆虫。该项目将通过实地观察、实验室水槽实验（操纵干旱条件以评估鲑鱼的生存和运动）和模拟不同的干燥程度来量化干旱对从水生生境向陆地生境输出营养物质的影响，从而量化鲑鱼的密度和出现时间。这个项目是第一个评估全球变化如何通过改变水生昆虫孵化和切断水生和陆地生态系统之间的联系来改变营养循环的项目之一。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Aquatic insects emerging from rivers during the hatch provide a major source of energy and nutrients to many predators. The nutrients, such as carbon and nitrogen, that are contained in aquatic insects are an important food subsidy to terrestrial ecosystems. However, insects are sensitive to and declining globally because of altered water availability, pollution, and temperature warming. Despite these widespread declines, little is known about how emergence may affect neighboring terrestrial ecosystems because the critical adult aquatic insect life-stage that allows energy and nutrients to be transferred from the aquatic environment to terrestrial consumers is sorely understudied in monitoring programs. This project investigates the role of a severe drying disturbance in regulating emerging aquatic insect hatches, in particular that of the salmonfly, which is a species of large aquatic insect in the stonefly order that is sensitive to global change. The researchers are evaluating how drastically reduced water flow from a dam gate failure influences salmonfly density, biomass, and emergence timing. A postdoctoral scholar and several undergraduate research assistants are being trained, a public survey on the topic of drought will be completed, and the research will be presented at a local festival in southwestern Montana. Public outreach will highlight the tight connections between water and land and the importance of emerging aquatic insects as a source of nutrients and energy to fish, birds, and mammals.This project will make transformative contributions to our understanding of the shifting role and resiliency of aquatic-terrestrial linkages under anthropogenic change by contributing novel information about the influence of a pulse drying disturbance on the adult life-stage of aquatic insects. The research project investigates how a dam malfunction on the Madison River in southwestern Montana that resulted in a short but extensive drying event could change aquatic insect emergence compared to prior years. The focal organism for the research is the giant salmonfly, which is an ecologically and culturally important aquatic insect in rivers in the Rocky Mountain West. The project will quantify salmonfly density and timing during emergence using field observations, laboratory flume experiments that manipulate drought conditions to assess salmonfly survival and movement, and simulations of different drying extents to quantify the influence of drought on export of nutrients from aquatic to terrestrial habitats. This project is one of the first to evaluate how global change alters nutrient cycles by changing aquatic insect hatches and severing ties between aquatic and terrestrial ecosystems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.