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

南极半岛东部的拉森冰架正在迅速退缩，从而使威德尔海西部的海洋生态系统（拉森区A和B）的环境条件发生了巨大变化：开阔的水域允许更高的初级生产，更高的有机物出口到海底，äs因此，海底在许多地点被新的底栖生物群落重新占领。这些不同于在冰架下贫营养条件下发现的贫瘠组合，这就提出了一个问题，底栖生物食物供应和群落组成的显著变化如何影响底栖生物生态系统功能（BEF）？BEF的重要组成部分是有机物的降解和相关的碳和无机营养物的再矿化。在极地地区，人们对这个问题知之甚少，更不用说这些底栖生物的过程已经和将如何响应南极冰架的持续退缩而发生变化。因此，本项目旨在(1)给出第一个量化；(2)确定冰架消失后（a和B）与海底有机物和群落组成变化相关的拉尔森冰架上底栖生物边界通量的变化；(3)利用实验方法评估整个拉尔森冰架（a、B和C）上底栖生物边界通量的未来变化。作为“海洋拉森冰架研究”（LASSO）的一部分，该项目的结果将导致一个概念性模型，描述冰架退缩对拉森地区底栖生态系统的影响。

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.