MSB: Dissertation Research: Methanotroph dynamics in response to lake mixing

湖泊和湿地被认为对全球碳循环做出了重大贡献，并可能在甲烷气体的生产中发挥特别重要的作用。然而，控制湖泊甲烷排放速率的生物和物理机制却知之甚少。该项目将研究消耗湖泊中甲烷的细菌(甲烷养殖菌)的多样性，并研究它们如何对季节性温度变化和破坏性事件引起的湖泊混合变化做出反应。否则，甲烷氧化菌在湖泊中消耗的甲烷将被释放到大气中。由于甲烷在湖底附近大量生成和积累，湖泊水柱的混合应该会扰乱甲烷氧化菌的活动，并加速甲烷的排放。该项目将采用一种新颖的全湖混合操作来研究甲烷氧化菌对湍流混合的反应，并将这种反应与大多数湖泊中季节性发生的更渐进的混合进行比较。甲烷是一种强有力的温室气体，通过增加地球大气层对太阳能的吸收，导致全球变暖。通过研究湖泊混合如何影响甲烷微生物组合和甲烷排放，该项目解决了将湖泊生态系统与全球气候变暖联系起来的重要反馈。该项目支持一名博士生的论文研究，也有助于让K-12教师参与到湖泊生态和气候变化的更大范围的推广工作中。

Lakes and wetlands are believed to contribute substantially to global carbon cycling, and may play an especially important role in production of methane gas. However, the biological and physical mechanisms that control rates of methane emission from lakes are poorly understood. This project will study the diversity of bacteria that consume methane in lakes (methanotrophs) and examine how they respond to changes in lake mixing caused by seasonal changes in temperature and by disruptive events. Methane consumed by methanotrophs in lakes would otherwise be released into the atmosphere. Since methane is created and accumulates largely near the bottom of lakes, mixing of the lake water column should disrupt the activities of methanotrophs and accelerate methane emission. This project will employ a novel, whole lake mixing manipulation to study how methanotrophs respond to turbulent mixing, and compare that response to the more gradual mixing that occurs seasonal in most lakes. Methane is a potent greenhouse gas that contributes to global warming by increasing absorption of solar energy in Earth's atmosphere. By studying how lake mixing impacts the methanotroph assemblage and methane emission, this project addresses an important feedback linking lake ecosystems and global climate warming. This project supports the thesis research of a doctoral student, and also contributes to a larger outreach effort that engages K-12 teachers in lake ecology and climate change.