Collaborative Research on Biogeochemistry of Antarctic Dry Valley Lakes: Seasonality and Feedback Processes in Amictic Lakes Dominated by Internal Cycling

温带湖泊生态系统既受季节变化的外部作用力影响，也受内部生物地球化学循环的影响；然而，水文混合和稀释可能掩盖了某些生物地球化学过程的重要性。相比之下，南极洲干谷的湖泊受季节性的影响极其简单，由永久的冰盖稳定，每年从冰川融水流中获得的化学成分，包括有机物质和营养物质的输入相对较少。因此，这些湖泊非常适合研究有机物质的内部生产和降解过程。本研究将重点关注南部冬季（持续黑暗）和南部夏季（持续白昼）发生的化学和生物变化，以及这些湖泊主要区域发生的过程之间的相互作用或反馈机制。这项研究将通过测量关键的自养和异养过程以及相关的化学参数、量化湖泊水文和在冬季部署采样设备来完成。这些湖泊生态系统的知识将增强我们对其他湖泊内部生物地球化学循环的理解。

Lake ecosystems in temperate zones are influenced both by seasonally-varying external forces and by internal biogeochemical cycling; however, hydrologic mixing and dilution may obscure the importance of some biogeochemical processes. In contrast, lakes in the Dry Valleys of Antarctica are influenced by a seasonality that is simple in the extreme, are stabilized by a permanent ice cover, and receive proportionately minor annual inputs of chemical constituents, including organic material and nutrients, from glacial meltwater streams. Therefore, these lakes are uniquely suited for the study of processes involved in the internal production and degradation of organic material. This study will focus on the chemical and biological changes occurring during the austral winter (constant darkness) and the austral summer (constant daylight) and on the interaction or feedback mechanisms between processes occurring in major zone of these lakes. The study will be accomplished by measuring key autotrophic and heterotrophic processes and related chemical parameters, by quantifying lake hydrology and by deploying sampling devices to operate during the winter. Knowledge of these lake ecosystems will enhance our understanding of internal biogeochemical cycling in other lakes.