Limnology and Biogeochemistry of Arctic Delta Lakes

北极三角洲湖泊的湖泊学和生物地球化学

• 批准号: RGPIN-2020-05478
• 负责人: Lesack, Lance
• 金额: $ 2.04万
• 依托单位: Simon Fraser University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=740613
• 关键词: Limnology; Biogeochemistry; Arctic; Delta; Lakes

Lakes associated with large river floodplains are among the most hydrologically complex, biologically productive, and biodiverse freshwater habitats in the world. They also face a wide range of threats and remain poorly understood because such systems represent vast areas of aquatic habitat world-wide, and global change is modifying the complex water level regimes that created these systems. The circumpolar Arctic coast is rich in such habitat, and is a region where climate is changing rapidly. The Mackenzie Delta is the second largest river floodplain in this region, and is one of the world's prominent aquatic ecosystems and a key ecosystem of the Canadian north because it functions as a biological hotspot relative to the surrounding arctic landscape. This delta is also on the leading edge of Arctic coastal changes because it is located in an area of subsidence that has enhanced relative sea level rise. It thus represents an exceptional model ecosystem to advance our fundamental understanding of aquatic habitat on large river floodplains. My long-term goal is to develop a general ecosystem paradigm for lakes on large river floodplains, not before possible, by teasing apart the varied mechanisms that create the combination of productivity, complexity, and diversity characteristic of these systems. This will advance our basic understanding of ecosystem complexity, and facilitate modeling of whether such systems respond resiliently or in surprising ways to multiple stresses of global change.       Over the next 5 years, I will focus on advancing our understanding of how changing coastal Arctic water levels will affect: (1) the ability of methane cycling microbial communities to either release carbon in these waters to the atmosphere as greenhouse gases or convert the carbon to forms consumed by fish and other organisms; and (2) the ability of Arctic delta habitat to function as a biogeochemical hotspot that affects delivery of riverine nutrients to the ocean. Our work represents an exceptional opportunity for training highly qualified people in Arctic fieldwork and in fundamental research of broad interest in aquatic and Arctic sciences.

与大型河漫滩相关的湖泊是世界上水文最复杂、生物生产力最高、生物多样性最丰富的淡水栖息地之一。它们还面临着各种各样的威胁，人们对它们的了解仍然很少，因为这些系统代表着世界范围内广阔的水生栖息地，而全球变化正在改变创造这些系统的复杂水位制度。极地周围的北极海岸有很多这样的栖息地，也是一个气候变化迅速的地区。麦肯齐三角洲是该地区第二大河流泛滥平原，是世界上著名的水生生态系统之一，也是加拿大北部的重要生态系统，因为相对于周围的北极景观，它是一个生物热点。这个三角洲也处于北极沿海变化的前沿，因为它位于一个下沉区域，这加剧了相对海平面的上升。因此，它代表了一个特殊的生态系统模型，促进了我们对大型河流洪泛区水生栖息地的基本理解。我的长期目标是通过梳理创造这些系统的生产力、复杂性和多样性特征组合的各种机制，为大型河流洪泛平原上的湖泊开发一个通用的生态系统范例，而不是在可能之前。这将促进我们对生态系统复杂性的基本理解，并有助于建立这样的系统对全球变化的多重压力是否有弹性或以令人惊讶的方式作出反应的模型。在接下来的5年里，我将重点推进我们对北极沿海水位变化将如何影响的理解：(1)甲烷循环微生物群落将这些水域中的碳作为温室气体释放到大气中或将碳转化为鱼类和其他生物消耗的形式的能力；(2)北极三角洲栖息地作为生物地球化学热点的能力，影响河流营养物质向海洋的输送。我们的工作代表了一个特殊的机会，培训高素质的人才在北极实地考察和基础研究的广泛兴趣在水生和北极科学。