Dynamik benthischer Ökosystemfunktionen in Abhängigkeit des Schelfeis-Zerfalls im westlichen Weddellmeer

南极半岛以东的拉森冰架一直在迅速后退，从而使威德尔海西部（拉森A区和B区）的人类生态系统受到环境条件的巨大变化：开阔水域允许更高的初级生产，更多的有机物质输出到海底，因此，许多地点的海底被rieh底栖生物群落所侵蚀。这些不同的贫困组合在贫营养条件下的冰架，这就提出了一个问题，如何在底栖动物的食物供应和社区组成的显着变化可能会影响底栖生态系统功能（BEF）？BEF的重要组成部分是有机物的降解以及相关的碳和无机营养物的矿化。在极地地区，人们对这一问题知之甚少，更不知道这些底栖生物的活动过程已经和将如何随着南极冰架的不断退缩而发生变化。因此，本项目的目的是：（1）提供第一个量化数据;（2）确定冰架丧失后拉森大陆架底栖边界通量的变化（A和B），这些变化与海底有机物和群落组成的变化有关;（3）用实验方法评价整个拉森大陆架底栖边界通量的未来变化（A、B和C）。作为“拉森大陆架海洋研究”的一部分，该项目的成果将产生一个概念模型，描述冰架退缩对拉森地区海底生态系统的影响。

The Larsen ice shelves east of the Antarctic Peninsula have been retreating rapidly, thus subjecting the manne ecosystem of the western Weddell Sea (Larsen areas A and B) to dramatic changes in environmental conditions: open water allows for higher primary production, higher export of organic matter to the seafloor, and äs a consequence, the seabed has been recolonized at many sites by rieh benthic communities. These differ frorn the impoverished assemblages found in oligotrophic conditions under the ice shelves, which raises the question, how the pronounced changes in benthic food supply and community composition may have influenced benthic ecosystem functioning (BEF)? Important BEF components are the degradation of organic matter and the associated remineralization of carbon and inorganic nutrients. Little is known about this issue in polar regions, and even less how these benthic processes have and will change in response to the continuing retreat of Antarctic ice shelves. This project therefore aims to (1) give a first quantification and (2) determine changes of benthic boundary fluxes on the Larsen shelf after loss of ice shelves (A and B) related to changes in organic matter on the seabed and community composition and (3) evaluate future changes of benthic boundary fluxes on the entire Larsen shelf (A, B, and C) using an experimental approach. As part of the 'Larsen Shelf Study of the Ocean' (LASSO), the outcome of this project will lead to a conceptual model describing the effects of ice shelf retreat on the benthic ecosystems in the Larsen region.