Collaborative Research: Wildlife subsidies interact with discharge to influence ecosystem function of a large African river

动物迁徙是自然界最引人注目的奇观之一，并能导致生态过程的重大工程。例如，迁徙的动物有可能在生态系统中移动大量的碳、氮和其他重要的营养物质。东非的马拉河支持着世界上现存最大的陆上迁徙：150万头角马和4000多只河马。本项目将采用小规模和全流实验、河流采样和理论模型来测试角马和河马向马拉河输入的营养物质如何与河流排放相互作用，从而影响初级生产、营养循环和整个生态系统代谢等生态系统过程。马拉河是少数未受管制的河流之一，受到大量野生动物种群的严重影响，为研究提供了独特的机会。研究结果将提高对大型野生动物发挥重要作用的生态系统的理解，并为与野生动物消失或被人类和驯养动物取代的系统进行比较提供基线。这项研究将涉及与野生动物和水质有关的区域问题。马拉河对塞伦盖蒂马拉生态系统至关重要，并为近100万农村贫困人口提供水。水质下降与伤寒和霍乱的爆发以及维多利亚湖的富营养化有关。此外，角马迁徙和大规模溺水事件也是马赛马拉国家公园管理人员关注的问题。研究还将涉及人类对河流的投入，这可能会告诉决策者如何更有效地处理污水才能使该地区受益。该项目将培养来自美国的本科生、研究生和一名博士后，以及来自东非各地的研究生。与国家地理学会和世界自然基金会（WWF）的合作将通过印刷品、视频和网络倡议传播研究成果。世界自然基金会的合作伙伴关系将使用玛拉的实时监测数据，现场摄像机陷阱的照片和博客更新，向利益相关者，资源管理者和公众传播调查结果。

Animal migrations are some of the most remarkable spectacles of nature and can result in significant engineering of ecological processes. For example, migrating animals have the potential to move large amounts of carbon, nitrogen, and other important nutrients among ecosystems. The Mara River in East Africa supports the largest remaining overland migration in the world: 1.5 million wildebeest and over 4,000 hippopotami. This project will use small-scale and whole-stream experiments, river sampling and theoretical models to test how nutrient inputs into the Mara River by wildebeest and hippopotami interact with river discharge to influence ecosystem processes such as primary production, nutrient cycling, and whole-ecosystem metabolism. The Mara River is one of the few remaining unregulated rivers heavily influenced by large wildlife populations, and provides a unique opportunity for research. Findings will improve understanding of ecosystems where large wildlife play an important role, and provide a baseline for comparison with systems where wildlife have disappeared or been replaced by humans and domesticated animals.This research will have relevance to regional concerns relating to both wildlife and water quality. The Mara River is critical to the Serengeti Mara ecosystem and provides water for nearly one million rural poor. Declining water quality has been linked to outbreaks of typhoid and cholera, and eutrophication of Lake Victoria. In addition, wildebeest migration and mass drowning events are of local concern to managers in the Maasai Mara National Park. Research will also address human inputs into the river, which may inform decision makers about how more effective sewage treatment could benefit the region. The project will train undergraduate students, graduate students, and a postdoc from the USA, and graduate students from around East Africa. Partnerships with the National Geographic Society and World Wildlife Fund (WWF) will distribute research results through print, video and web-based initiatives. The WWF partnership will use real-time monitoring data from the Mara, photos from live camera traps, and blog updates to disseminate findings to stakeholders, resource managers, and the public.