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察到的最快速度变暖。特别是，北极湖正在经历更频繁的几年更温暖和更深的表层水。然而，检测和量化生态系统影响和对这些气候变化的具体生物反应的能力主要限于非机械性的模拟情景和在不受控制的环境中进行的观测研究。这些湖泊为北极土著社区提供了自给自足的收成，重要的是要了解在持续变暖的情况下，可持续收成的水平可能会如何变化。该项目将操纵选定的北极湖泊的温度状况，观察湖泊生态系统随之而来的变化，并对其进行模拟。该项目将通过为两个机构的研究生培训提供支助，促进科学、技术和经济管理部门的劳动力发展。它还将吸引本科生参与这项研究。通过与美国鱼类和野生动物服务局的合作，主要调查人员将通过Kaktovik科学营向Iñupiat高中生提供外联服务，并通过北极村科学营Goonzhii向Iñupiat K-12年级的学生提供外联服务。他们将通过与美国鱼类和野生动物服务机构和阿拉斯加鱼类和猎物部门建立合作，以及通过与当地社区(如阿拉斯加北坡行政区)的互动研讨会系列，通过演讲为自然资源的管理做出贡献。该项目将完成一个多年的、全湖变暖的操纵，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反应相结合，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：变暖的湖泊温度和延长的生长季将如何改变(1)湖泊冰覆盖和年度热状况；(2)初级和次级生产者的丰度、活动性和多样性；(3)鱼类的生命速率、产量和动态；以及(4)生长季的结转程度和累积影响。实验结果将与长期的存档数据相结合，以提供一个链接的建模系统(湖泊-气候耦合模型和集成的物理、气候、生物和生物能量模型)来回答：(1)湖泊温度变暖和生长季延长将如何改变：(1)区域尺度的湖泊热状况；(2)北极湖泊类型的鱼类种群。这项研究将量化湖泊热过程和湖泊大气反馈，提供更精确的湖泊水平和垂直温度结构预测，并记录和预测湖泊生物群和生态系统在大空间尺度和不同气候情景下对湖泊热状况变化的响应。

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.