In the frame of the DFG-project “PycnoTrap” on microbial aggregate degradation and carbon cycling in aquatic ecosystems we are inviting applications for a PhD position in close collaboration with a second PhD position in lake physics. The successful candidate will be part of an interdisciplinary international team with German and Siberian lakes as primary research objects. The PhD study will be focused on microbial dynamics of organic matter driving the aggregation and degradation of organic particles in thermally stratified inland waters. The approaches encompass molecular tools for analysis of microbial community composition and functions and biochemical methods to quantify organic matter sinking and turnover. The study will be performed in close collaboration with the physics and biogeochemistry teams of the project allowing for intense knowledge exchange between different scientific disciplines and researchers. The workplace is at department III (Experimental Limnology) in Stechlin-Neuglobsow (80 km north of Berlin) with frequent visits of the IGB in Berlin, where the physics team is located. Several medium-term visits to remote sites in Siberia are envisaged as part of the field work.
Inland waters such as lakes and reservoirs play a substantial role in the transport and transformation of both terrestrial and autochthonous organic carbon. The key internal pathway for aquatic carbon dynamics, i.e. sinking of particulate organic matter (POM), strongly depends on microbial degradation and vertical density stratification of the water column. Yet, the integral quantitative effects of microbial activities and water column stratification on POM transformation remain largely unknown. This project aims to shed light on the changing role of water column density gradients for POM sinking behaviour and hence its impact on microbial carbon cycling in inland waters.