Collaborative Research: An Exploration of the Direct and Indirect Effects of Climatic Warming on Arctic Lake Ecosystems

北极生态系统正在以地球上观测到的最快速度变暖。特别是，北极湖泊正在经历更频繁的温暖和更深的地表水年份。然而，检测和量化生态系统效应和对这些气候变化的特定生物反应的能力主要局限于非机械模拟情景和在不受控制的环境中的观测研究。这些湖泊为北极地区的土著社区提供了维持生计的收获，了解可持续收获水平在持续变暖的情况下如何变化是很重要的。该项目将操纵选定的北极湖泊的温度状况，观察湖泊生态系统的随之变化，并建立模型。该项目将通过为两所院校的研究生培训提供支持，促进STEM劳动力的发展。它还将吸引本科生参与研究。通过与美国鱼类和野生动物管理局的合作，主要研究人员将通过Kaktovik科学营向Iñupiat高中生和通过Goonzhii北极村科学营向Iñupiat K-12学生提供外展服务。他们将通过与美国鱼类和野生动物管理局和阿拉斯加渔猎部的合作，以及与当地社区（如阿拉斯加北坡自治市）的互动系列研讨会，为自然资源的管理做出贡献。该项目将完成一项多年的全湖变暖控制，以量化未来气候变化对北极湖泊生态系统的影响。此外，区域气候和湖泊模型将与生物响应相结合，以更好地了解湖泊对不断变化的大气条件的敏感性。该项目旨在回答：湖泊温度升高和生长季节延长将如何改变(1)湖泊冰覆盖和年热状态；(2)第一和第二生产者的丰度、活跃度和多样性；(3)鱼类活力、产量和动态；(4)不同生长季节的结转程度和累积效应。实验结果将与长期的存档数据相结合，为关联的建模系统（耦合湖泊气候模型和综合物理、气候、生物和生物能量模型）提供信息，以回答：湖泊温度升高和生长季节延长将如何改变：(1)区域尺度上的湖泊热状态，(2)北极湖泊类型的鱼类种群。该研究将量化湖泊热过程和湖-气反馈，提供更精确的湖泊水平和垂直温度结构预测，并在大空间尺度和不同气候情景下记录和预测湖泊生物和生态系统对湖泊热条件变化的响应。

Arctic ecosystems are warming at some of the fastest rates observed on earth. In particular, Arctic lakes are experiencing more frequent years of warmer and deeper surface water. However, the ability to detect and quantify ecosystem effects and specific biological responses to these climatic changes has been primarily limited to non-mechanistic modeled scenarios and observational studies in uncontrolled environments. These lakes provide subsistence harvest for native communities in the Arctic and it is important to understand how the level of sustainable harvests might change under scenarios of continued warming. This project will manipulate the temperature regime of selected Arctic lakes, observe the consequent changes of the lake ecosystem, and model these. This project will contribute to STEM workforce development through provision of support for the training of graduate students at two institutions. It will also entrain undergraduate students into the research. Through a collaboration with the US Fish and Wildlife Service, the principal investigators will provide outreach to Iñupiat high school students via the Kaktovik Science Camp and to Iñupiat K-12 students via the Arctic Village Science Camp Goonzhii. They will contribute to the management of natural resources by presentations through established collaborations with the US Fish and Wildlife Service and the Alaska Department of Fish and Game, as well as through an interactive seminar series with local communities, e.g. the North Slope Borough of Alaska.This project will complete a multi-year, whole-lake warming manipulation, to quantify the effects of future climate change on lake ecosystems in the Arctic. In addition, regional climate and lake models will be coupled with biotic responses to better understand the sensitivity of lakes to changing atmospheric conditions. The project is designed to answer: How will warmer lake temperatures and extended growing season alter (1) lake ice coverage and annual thermal regime; (2) abundance, activity, and diversity of primary and secondary producers; (3) fish vital rates, production, and dynamics; and (4) degree of carry-over across growing seasons and cumulative effects. Experimental results will be combined with long-term, archived data to inform a linked modeling system (coupled lake-climate model and integrated physical, climate, biological, and bioenergetic modeling) to answer: How will warmer lake temperatures and an extended growing season alter: (1) lake thermal regimes at regional scales, and (2) fish populations across lake types of the Arctic. This research will quantify lake thermal processes and lake-atmosphere feedbacks, provide more precise projections of lake horizontal and vertical temperature structures, and document and project lake biota and ecosystem responses to changes in lake thermal condition over large spatial scales and under different climate scenarios.