Antarctic Research: Microbial-mediated soil formation in maritime Antarctica under simulated environmental conditions

At least since the convention on biodiversity in Rio de Janeiro, 1992, soils are recognized as the essential medium for sustainability on the planet. Water and nutrient supply to vegetation, natural habitat for organisms and reactor of key elements of life such as C, N and P are probably the most important functions of soils for life on earth. As such, the living soil fulfils life-support functions that sustain life also in extreme environments like the Antarctic. This offers the exceptional chance to explore diversity and functioning of microbial communities in soils and their interrelations with soil forming processes. In Antarctica, soil formation proceeds without the influence of higher vegetation and burrowing animals. Furthermore, research on microbial-mediated soil formation allows conclusions about the impact of the isolation of Antarctica on biological evolution and about the response of microbial evolution and soil formation to environmental change. The proposed project seeks to analyse microbial-mediated soil formation under simulated environmental conditions in maritime Antarctica. We focus on how microbial community structures control carbon fixation and formation of micro-aggregates as one of the major initial processes of soil formation in juvenile sediments. In this respect, we will analyse initial soils and sediments from maritime Antarctica in an integrated and interdisciplinary approach combining microbiology and soil science. At first, we will comprise molecular ecological studies and pedogenic analyses to elucidate the impact of microbial communities on early soil formation under the given environmental conditions in maritime Antarctica. This will allow analysing site variations within the microbial community composition in relation to pedogenic processes. Following, we will conduct an Environmental Simulation Experiment (EnviSimEx) in the laboratory to study the impact of environmental changes (temperature, moisture, organic matter, freeze-thaw cycling) on initial pedogenic processes and microbial communities. EnviSimEx performs with and without microorganisms and will thus help to clarify the role of microorganisms on early soil formation and its feedback processes. We will combine microbiological and pedogenic methods in an integrative approach. Real time PCR and DGGE fingerprinting as well as next generation sequencing will be applied to analyse the structure and function of microbial communities. Soil physicochemical analyses will be done to determine weathering intensity, pedogenic processes and soil properties. Cutting-edge micromorphological techniques and NanoSIMS will help to identify and characterize microbial hotspots as well as translocation and transformation processes in soils and sediments.