Long-term Ecological Research (LTER) on the Antarctic Marine Ecosystem: Microbiology and Carbon Flux

浮冰的年度进退可能是南极海洋群落结构和功能时空变化的主要物理决定因素。每年积冰范围的年际循环和/或趋势也可能对食物网的各个层面产生重大影响，从年度初级总产量到海鸟的繁殖成功。历史记录表明，冬季积冰的最大范围为6至8年。在这十年中，1980年和1981年的冬天更冷，1986年和1987年又是如此。为了了解浮冰与生态系统动力学之间的相互作用，特别是冰盖年际变化对典型种群的影响，在南极半岛帕尔默站附近建立了一个长期生态研究(LTER)站点。LTER项目将对该地区以冰为主的生态系统进行全面测量，重点是初级生产、磷虾种群以及群体和海鸟。将把主要重点放在开发生态系统模型上，这些模型将为与全球环境变化有关的问题提供预测能力。这项提议将在现有LTER项目的基础上，增加对碳和相关生物元素的生物地球化学循环的详细研究。LTER的微生物学和碳通量部分将提供一套与碳循环相关的核心参数的测量，并将测试几个与碳通量有关的假设，包括细菌生产力和营养再生。

The annual advance and retreat of pack ice may be the major physical determinant of spatial/temporal changes in the structure and function of antarctic marine communities. Interannual cycles and/or trends in the annual extent of pack ice may also have significant effects on all levels of the food web, from total annual primary production to breeding success in seabirds. Historical records indicate a 6 to 8 year cycle in the maximum extent of pack ice in the winter. During this decade winters were colder in 1980 and 1981, and again in 1986 and 1987. In order to understand the interactions between pack ice and ecosystem dynamics, especially the influences of the well- documented interannual variability in ice cover on representative populations, a long-term ecological research (LTER) site has been established in the Antarctic Peninsula region near Palmer Station. The LTER project, will conduct comprehensive measurements of ice-dominated ecosystems in this region with a focus on primary production, krill populations and swarms and seabirds. A primary emphasis will be placed on the development of ecosystem models that will provide a predictive capability for issues related to global environmental change. This proposal will add to the existing LTER project detailed studies of the biogeochemical cycling of carbon and associated bioelements. The microbiology and carbon flux component of LTER will provide measurements of a suite of core parameters relevant to the carbon cycle and will test several hypotheses pertaining to carbon flux, including bacterial productivity and nutrient regeneration.