LTREB Renewal: High-amplitude midge fluctuations and the ecosystem dynamics of Lake Myvatn, Iceland

蝗虫、旅鼠、昆虫等生物的戏剧性“爆发”吸引了公众对自然界的关注，部分原因是科学家们还没有完全理解这些人口激增的原因。这项研究将调查冰岛Mackovatn湖的摇蚊，以及为什么它们的丰度在持续4-7年的不规则周期中波动超过4个数量级。从湖里出来的成蚊死在海岸上。在高蠓年，沉积在周围石南荒原的蠓的重量相当于10头座头鲸，为捕食者和食腐动物提供食物，为植物提供营养，并为当地农业提供基础。通过综合几个人口周期的实地样本和实验结果，该项目有望对有关人口爆发的原因和后果的基本科学问题提出新的见解。该项目将吸引研究生和本科生，他们每年夏天都将在Mengvatn工作，为他们提供极端生物学以及教育多样性，因为他们在跨学科科学家小组的指导下在湖泊和海岸线上工作。公众将通过一个正在进行的“蚊子的Smidge”博客了解更多关于蚊子爆发的信息。随着时间的推移，生态系统显示出巨大的变化，可以揭示稳定或破坏自然动态的生态力量。该项目涉及水生和陆地系统的长期数据收集和有针对性的实验，以测试特定的假设。水生数据收集将建立和扩大可追溯到1970年代的现有数据库。该项目增加了对许多其他变量的每周监测，包括蠓幼虫密度、底栖生物初级生产量和水层营养物。陆地数据的收集工作继续进行，监测了2008年确定的沿湖沿着的蚊群和节肢动物群落。一套有针对性的实验将解决一系列广泛的研究问题，如（一）作为生态系统工程师，改变底栖条件，有利于大型底栖枝角类动物的小型底栖物种，（二）的互利互惠的影响，蠓幼虫对藻类的生长，和（三）的重要性，蠓成人的开花的食肉植物。这些实验项目由研究生领导，作为博士论文的一部分，并由本科实习生作为独立项目。这种水生和陆生实验与定期取样相结合的方式将检验关于湖泊和海岸线生态系统如何联系在一起的假设。该研究将研究湖泊生态系统的不稳定是否会导致周围陆地生态系统的不稳定。

Dramatic 'outbreaks' of organisms - locusts, lemmings, insects - draw public attention to the natural world, in part because scientists do not completely understand the causes for these population surges. This study will investigate midges in Lake Mývatn, Iceland, and why their abundance fluctuates over 4 orders of magnitude in irregular cycles lasting 4-7 years. Adult midges that emerge from the lake die on shore. During high-midge years, the weight of midges that are deposited in the surrounding heathland is equivalent to 10 humpback whales, providing food for predators and scavengers, nutrients for plants, and the basis for local agriculture. By synthesizing results from field samples and experiments over several population cycles, this project promises new insights into fundamental scientific questions about the causes and consequences of population outbreaks. The project will engage graduate and undergraduate students who will work at Mývatn each summer, providing them exposure to extreme biology as well as to educational diversity, as they work in both the lake and on the shoreline under the tutelage of an interdisciplinary group of scientists. The public will learn more about midge outbreaks through an ongoing 'Smidge of Midge' blog.Ecosystems that show huge changes through time can reveal the ecological forces that stabilize or destabilize natural dynamics. This project involves both long-term data collection in aquatic and terrestrial systems and targeted experiments to test specific hypotheses. The aquatic data collection will build and expand on an existing database that dates back to the 1970s. The project has added weekly monitoring of many additional variables, including midge larvae density, benthic primary production, and pelagic nutrients. The collection of terrestrial data has continued with the monitoring of midge infall and arthropod communities along transects around the lake that were established in 2008. A suite of targeted experiments will address a wide range of research questions such as (i) the role that midges play as ecosystem engineers, changing benthic conditions to favor large-bodied epibenthic cladocerans over small-bodied infaunal species, (ii) the mutualistic effect that midge larvae have on algal growth, and (iii) the importance of midge adults for the flowering of carnivorous plants. These experimental projects are led by graduate students as part of their PhD theses, and by undergraduate interns as independent projects. This combination of aquatic and terrestrial experiments together with regular sampling will test hypotheses about how the lake and shoreline ecosystems are linked together. The research will examine whether the instability of the lake ecosystem could drive instability of the surrounding ecosystem on land.