Impact of climate variability on the bentho-pelagic coupling in a large river

底栖生物在控制河流水系浮游生物方面发挥着重要作用。底栖生物的损失程度在很大程度上取决于与气候有关的因素，即温度和降雨量（水位）。浮游生物的生长与底栖生物的丧失之间的平衡不匹配可能会严重影响生态系统的功能。本文旨在以莱茵河为模型系统，提供数据来解释和预测底栖生物对不同浮游生物类群发育的影响，以应对气候条件的变化。在正常条件下，河流中底栖生物和远洋生物群落之间的营养相互作用比静水中密切得多。将采用不同的方法，包括实地研究和底-上层耦合的实验。实验将在不同的河道中进行，包括河流旁路系统，以评估底栖生物关键物种和底栖生物群落在温度变化条件下对不同浮游生物类群的影响。将在实地调查潜在底栖动物消费者（特别是与生物膜有关的动物）的时空动态。此外，在长期取样活动的基础上，将继续分析重要浮游生物类群的动态，重点是气候变化对浮游生物组成的影响。如果底栖-远洋相互作用的匹配/不匹配发生重大变化，这将对河流系统的功能（有机化合物的降解等）产生巨大影响。我们研究的主要目的是分析可能不匹配的条件。一般认为，与湖泊或海洋系统相比，随着全球气候变化，河流系统将面临最大的环境变化。

Benthic consumers can play an important role in controlling plankton in river systems. The degree of the loss to the benthos is strongly dependent on climate related factors, i.e. temperature and rain fall (water level). Mismatches in the balance between the growth of planktonic organisms and their loss induced by the benthos might strongly influence the ecosystem function. Here we aim to provide a data to explain and predict the benthic impact on the development of different plankton groups in response to changing climate conditions using River Rhine as a model system. Under normal conditions the trophic interactions between benthic and pelagic communities in rivers are much closer than in standing waters. Different approaches including field studies as well as experiments on the bentho-pelagic coupling will be applied. The experiments will be conducted in different flow channels including river bypass systems in order to estimate the impact of benthic key species and benthic communities on the different plankton groups under changing temperature condition. The spatial and temporal dynamics of potential benthic consumers (especially among the biofilm-associated fauna) will be investigated in the field. In addition, based on a long term sampling campaign, the analysis of the dynamics of significant plankton groups will be continued with focus on the impact of climate variations on the plankton composition. If there are significant changes in the matches/mismatches of bentho-pelagic interactions this would have tremendous influences on the functioning of river systems (degradation of organic compounds, etc.). The major aim of our study will be the analysis of conditions for possible mismatches. River systems are generally expected to face the greatest environmental changes with global climatic changes compared to lake or marine systems.