Collaborative Research: Biogeochemistry of Dissolved Organic Matter in Pony Lake, Ross Island

溶解有机物（DOM）是水生系统中重要的化学成分，因为它是微生物的重要碳源，吸收阳光中的有害辐射，能够复合金属，并能参与重要的生物地球化学反应。本研究将研究位于罗斯岛罗伊兹角的一个小型南极沿海池塘——小马湖（Pony Lake）中DOM的生物地球化学循环。由于该地点没有高等植物存在，因此湖中所有的DOM都来自微生物。因此，Pony Lake是研究物理、化学和微生物过程对DOM池组成和特征影响的理想场所。最后，Pony Lake也是收集国际腐殖质协会（IHSS）黄腐酸标准的理想场所。与其他IHSS标准不同，本标准不包含来自高等陆地植物的DOM组件。为了更好地了解物理影响的作用，该项目将研究夏季湖泊从冰覆盖到无冰状态时DOM池的变化，以及DOM与观察到的湖中优势微生物群落更替的关系。科学家还将监测在冰向开放水域过渡期间可能发生的微生物丰度、多样性和生产力的变化。该研究将为微生物多样性与DOM生物地球化学之间的关系提供必要的信息。中学生将通过互联网积极参与这个项目，而科学家则在现场和实验室。

Dissolved organic matter (DOM) is a significant chemical component in aquatic systems because it acts as an important carbon source for microorganisms, absorbs harmful radiation in sunlight, is able to complex metals, and can participate in important biogeochemical reactions. This study will investigate the biogeochemical cycling of DOM in a small coastal Antarctic pond, Pony Lake, located on Cape Royds, Ross Island. Because there are no higher plants present at this site all of the DOM in this lake is derived from microorganisms. Thus, Pony Lake is an ideal site to study the effect of physical, chemical, and microbial processes on the composition and character of the DOM pool. Finally, Pony Lake is also an ideal site to collect an International Humic Substances Society (IHSS) fulvic acid standard. Unlike other IHSS standards, this standard will not contain DOM components derived from higher land plants. To better understand the role of physical influences, the project will study the changes in the DOM pool as the lake evolves from ice-covered to ice-free conditions during the summer, as well as the relationship of DOM to the observed turnover of dominant microbial communities in the lake. Scientists will also monitor changes in microbial abundance, diversity, and productivity that may occur during the ice to open-water transition period. This research will provide much needed information regarding the relationship between microbial diversity and DOM biogeochemistry. Middle school science students will be active participants in this project through the Internet, while scientists are in the field, and in the lab.