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产生中发挥特别重要的作用。然而，控制湖泊甲烷排放率的生物和物理机制尚不清楚。该项目将研究湖泊中消耗甲烷的细菌（甲烷氧化菌）的多样性，并研究它们如何应对由季节温度变化和破坏性事件引起的湖泊混合变化。否则，湖泊中甲烷氧化菌消耗的甲烷将被释放到大气中。由于甲烷主要是在湖底附近产生和积累的，因此湖泊水柱的混合应该会破坏甲烷氧化菌的活动，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，通过增加地球大气对太阳能的吸收而导致全球变暖。通过研究湖泊混合对甲烷营养菌组合和甲烷排放的影响，本项目解决了湖泊生态系统与全球气候变暖之间的重要反馈。该项目为一名博士生的论文研究提供支持，也为一项更大的外联工作做出了贡献，该工作吸引了K-12教师参与湖泊生态和气候变化。

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.