Lakes in the Anthropocene: Studying lake ecosystem changes across broad spatial and temporal scales

生态学家和环境科学家面临的最大挑战之一是缺乏可靠的长期观察。然而，研究生态转变和阈值，特别是在人类影响的人类世期间，往往需要长期的观点（通常是提前确定直接观测记录的年代）。幸运的是，经过战略选择的湖泊和泥炭沉积物通常会保存过去变化的可靠记录，可以为许多重要问题提供答案。本建议使用已建立的、新发展的和正在发展的古环境方法来研究全球环境变化的不同方面。主题1通过针对海鸟生物载体的项目，将古湖泊学与保护生物学领域融合在一起，并利用古湖泊学记录来追踪鸟类种群的过去变化及其生态影响（例如，将营养物质和污染物集中到食物网中）。保护生物学家很少知道灭绝和受威胁物种的历史种群规模，或者历史种群波动如何对应于人类影响、气候变化和其他环境压力。我们将与加拿大一些领先的鸟类学家密切合作，重点研究具有国家和国际重要性的种群和物种，研究鸟类在一组战略选择的地点随时间（十年到千年尺度）的变化轨迹，这将使我们能够在更广泛的长期环境和气候背景下评估这些变化。提出的问题包括：鸟类群落在数百年到数千年的时间和空间中是如何动态的？当它们的陆地或海洋栖息地发生环境变化时，海鸟会在景观中移动吗？在长期尺度上影响这些变化的因素是什么？主题2将我们在北极的古湖泊学工作扩展到“北部五大湖”的研究。尽管在了解较小的北极湖泊和池塘的生态转变和阈值变化方面取得了相当大的进展，但在大奴湖和大熊湖等北部大型湖泊的类似研究却落后于此。我们将为这些未被充分研究的北方五大湖解决基本问题，包括：这些湖泊的基线状态是什么？最近的气候变暖和其他人为压力因素是如何影响这些湖泊的？这些变化与较小湖泊报告的变化相比如何？总的来说，这些项目将为培养下一代生态学家和环境科学家提供绝佳的机会，解决与保护生物学和水生生态学相关的基础和应用问题，同时为决策者和其他对使用循证管理策略感兴趣的利益相关者提供关键信息。

One of the greatest challenges faced by ecologists and environmental scientists is the lack of reliable long-term observations. Yet, long-term perspectives (often pre-dating direct observational records) are often required for the study of ecological transitions and thresholds, and particularly during the human-impacted Anthropocene period. Fortunately, strategically selected lake and peat deposits often archive a robust record of past changes that can provide answers to many important questions. This proposal uses established, newly developed, and developing paleoenvironmental approaches to investigate different aspects of global environmental change. Theme 1 melds paleolimnology with the field of conservation biology through projects directed at seabird biovectors, and the use of paleolimnological records to track past changes in avian populations as well as their ecological repercussions (e.g. focussing of nutrients and contaminants into foodwebs). Conservation biologists rarely know the historical population sizes of extinct and threatened species, or how historical population fluctuations correspond to human influence versus climate change, and other environmental stressors. Working in close collaboration with some of Canada's leading ornithologists and focusing on colonies and species of national and international importance, we will study trajectories over time (on decadal to millennial scales) of avian inputs to a strategically selected suite of sites, which will allow us to assess these changes within the broader long-term environmental and climatic context. Questions posed include: How dynamic are bird colonies in space and time on the order of hundreds to thousands of years? Do seabirds move about the landscape as environmental changes occur in their terrestrial or marine habitat? What are the factors influencing these changes on long-time scales? Theme 2 expands our paleolimnological work in the Arctic to studies of the “Northern Great Lakes”. Although considerable progress has been made in understanding ecological transitions and threshold shifts in smaller Arctic lakes and ponds, similar research has lagged in large northern lakes such as Great Slave Lake and Great Bear Lake. We will address fundamental questions for these understudied Northern Great Lakes including: What are the baseline states of these lakes? How has recent warming and other anthropogenic stressors affected these lakes and how do these changes compare to changes reported in smaller lakes? Collectively, these projects will provide outstanding opportunities for the training of our next generation of ecologists and environmental scientists, addressing both fundamental and applied questions linked to conservation biology and aquatic ecology, while providing key information for policymakers and other stakeholders interested in using evidence-based management strategies.