Research on Antarctic Coastal Ecosystem Rates (RACER): Microbial Dynamics and Carbon Flux

南大洋维持着一个温和的，但不完整的， 尽管环境条件恶劣，但生产力（低） 温度、长时间的持续黑暗、深层垂直混合 （表沃茨）。 南极沿海生态系统的初级生产 其特点是密集的春季开花，这是由一个 同时增加水柱稳定性和可用性， 太阳辐射 花期持续时间一般少于2-3天 几个月，在此期间，沿海南极生态系统收到 约占其年有机碳产量的70-90%。 净 固定碳的这种时间脉冲的作用是增加生物活性， 从细菌到须鲸，所有营养层次的生产力。 然而，碳转移的精确途径，以及 其中涉及的机制尚未被仔细研究。 在 特别是微异养生物在南极食物网中的作用， 需要阐明浮游植物生产直接结果。 作为 RACER（南极海岸生态系统速率研究） 计划，该项目将评估几个基于生态预测 根据中心的工作假设，这些假设涉及的物理特性， 水柱到生物生产力的时间脉冲。 研究工作将试图确定机制，途径和 光合自养和异养种群间的耦合率 并评价水层生境和底栖生境之间的相互关系。 在这次考察中获得的数据将增加一个整体 了解初级和次级生产率，并将 最终将被用于制定碳和能源的通用模型 南极海岸生态系统的流动。

The southern ocean maintains a moderate, but patchy, biological productivity in spite of harsh environmental conditions (low temperature, extended periods of constant darkness, deep vertical mixing of surface waters). Primary production in coastal Antarctic ecosystems is characterized by an intensive spring bloom which is initiated by a simultaneous increase in water column stability and availability of solar radiation. The duration of the bloom is generally less than 2-3 months, during which time the coastal Antarctic ecosystem receives approximately 70-90% of its annual organic carbon production. The net effect of this temporal pulse of fixed carbon is to increase biological productivity at all trophic levels, from bacteria to baleen whales. However, the precise pathways of carbon transfer, and the rates and mechanisms involved therein have not been carefully investigated. In particular, the role of microheterotrophs in Antarctic foodwebs and the immediate fate of phytoplankton production need to be elucidated. As part of the RACER (Research on Antarctic Coastal Ecosystem Rates) program, this project will evaluate several ecological predictions based upon central working hypotheses which relate physical characteristics of the water column to the temporal pulse of biological productivity. Research efforts will attempt to define the mechanisms, pathways and rates of coupling between photoautotrophic and heterotrophic populations and to evaluate the coupling between the pelagic and benthic habitats. The data obtained during this expedition will add to an overall understanding of the rates of primary and secondary production, and will ultimately be used to formulate a general model of carbon and energy flow in Antarctic coastal ecosystems.