Role of meio- and macrofauna in benthic ecosystem functioning: Testing effects of different ice cover regimes

小型和大型动物在底栖生态系统功能中的作用：测试不同冰盖状况的影响

• 批准号: 365901123
• 负责人: Dr. Heike Link
• 金额: --
• 依托单位: Lehrstuhl für Meeresbiologie
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/365901123?language=en
• 关键词: Role; meio; macrofauna; benthic; ecosystem

Many ecosystems around Antarctica are undergoing rapid changes, particularly in ice cover dynamics. It is not known if and how this development influences the processes at the seafloor, the benthic functions. For a comprehensive understanding of ecosystem functioning it is, hence, necessary to determine the role of different ecosystem components (e.g. faunal community groups) for seafloor processes under changing and stable ice cover regimes. Few studies have investigated different size classes and communities of organisms, like meio- and macrofauna, in this benthic environment simultaneously. And none has studied their complementary role for benthic functions. Influences of reduced or changing ice cover on trophic interactions among and the relative importance of meio- and macrofauna taxa are not understood. How benthic boundary fluxes (ammonium, nitrate, phosphate, silicic acid, oxygen) are affected by different ice cover regimes in the Weddell Sea is unknown. And virtually nothing is known about the partitioning of organic matter remineralisation between the meiobenthic and macrobenthic community compartment in the Southern Ocean. In this 3-year project, we propose to jointly evaluate the response of benthic ecosystem functioning to ice cover regimes and their changes in the Weddell Sea and the vicinity of the Antarctic Peninsula. To better understand the particular roles of the different size compartments and their associated taxa in the sediment system we need to determine (1) the role of meio- and macrofauna community structure for food uptake and benthic remineralisation in regions with different ice regimes and (2) the effect of variations in food input as a result of changing ice regimes on this benthic function - faunal size compartment relation.The two complementary aspects will be studied as two work packages with one joint doctoral student, leading to a third synthesis work package. Samples are available from the expeditions of RV Polarstern PS 81 (22.01 to 18.03.2013) to around the Antarctic Peninsula and PS 96 (06.12.2015 to 14.02.2016) to the south eastern Weddell Sea. The sampled area includes sites with reduced, variable and lasting ice cover regime. Thus, we can study remineralisation efficiency of both benthic compartments and relate it to food web position of meio- and macrofauna taxa in different regions. Further, we experimentally test remineralisation response (benthic boundary fluxes and food uptake) at the sediment-water interface and trophic interactions under natural and replicated pulse-chase experimental conditions. In the third (synthesis) work package we will construct a conceptual model for the evaluation of benthic ecological functioning in the Southern Ocean. By combining faunal size classes and different benthic processes synchronously for the first time, it will be possible to evaluate, what the net ecological effect of changing ice cover regimes on the Weddell Sea benthic system could be.

南极洲周围的许多生态系统正在经历快速变化，特别是在冰盖动态方面。目前尚不清楚这一发展是否以及如何影响海底的进程，即海底功能。因此，为了全面了解生态系统的功能，有必要确定不同生态系统组成部分（例如动物群落）在不断变化和稳定的冰盖制度下对海底过程的作用。很少有研究同时调查这种底栖环境中不同大小的生物种类和群落，如小型和大型底栖动物。也没有人研究它们对底栖生物功能的补充作用。冰盖减少或变化对小型和大型底栖动物类群之间营养相互作用的影响以及它们的相对重要性尚不清楚。底栖边界通量（铵、硝酸盐、磷酸盐、草酸、氧）如何受到威德尔海不同冰盖状况的影响尚不清楚。事实上，人们对南大洋小型底栖动物和大型底栖动物群落隔间之间的有机物矿化分配一无所知。在这个为期3年的项目中，我们建议共同评估威德尔海和南极半岛附近的底栖生态系统功能对冰盖状况及其变化的响应。为了更好地了解不同大小的隔间及其相关类群在沉积物系统中的特殊作用，我们需要确定（1）在不同冰况的区域中，小型和大型底栖动物群落结构对食物吸收和底栖生物同化的作用，以及（2）由于冰况的变化而导致的食物输入变化对底栖生物功能的影响-这两个互补的方面将作为两个工作包与一名联合博士生一起研究，从而产生第三个综合工作包。可从前往南极半岛周围的RV Polarstern PS 81（2013年1月22日至3月18日）和前往威德尔海东南部的PS 96（2015年12月6日至2016年2月14日）探险队获得样本。取样地区包括冰盖减少、变化和持久的地点。因此，我们可以研究两个底栖舱室的矿化效率，并将其与不同区域的小型和大型底栖动物类群的食物网位置联系起来。此外，我们在实验上测试在自然和复制脉冲追逐实验条件下的沉积物-水界面和营养相互作用的矿化反应（底栖边界通量和食物吸收）。在第三个（综合）工作包中，我们将建立一个概念模型，用于评价南大洋底栖生态功能。通过首次同步结合动物群大小类别和不同的海底过程，将有可能评估冰盖状况变化对威德尔海海底系统的净生态影响。