Microbes in poly-extreme environments and their potential roles in greenhouse gas release: Gruve 5, an acidic polar peat-draining AMD river

Peat soils store vast amounts of soil organic carbon (SOC) and are of importance with regards to climate change. We aim to identify and compare key microbial players of the soil in a peat-draining poly-extreme environment (acidic polar Acid Mine Drainage river) in Svalbard due to its physicochemical differences with other Arctic peat soils and potential significance in the production of greenhouse gases. The proposed study will identify key microbial players as well as distinguish old, peat-derived carbon from new, recently fixed carbon and quantify fluvial pathways for peat carbon loss as both organic and inorganic carbon, by comparing fluxes of carbon in POC, DOC and DIC in a poly-extreme river draining from pristine peat. DGGE and pyrosequencing will be utilised to assess microbial diversity, as well as the cultivation and short sediment cores to obtain vertical profiles of microbial distribution in the active surface layers. CO2 concentrations, 14C-DIC, 14C-DOC, 14C-POC, major ions and water isotopes will be analysed. The 14C content of POC, DOC and DIC will be determined by accelerator mass spectrometry and reported as percent Modern Carbon (pMC). Results obtained from the proposed study will be the first of its kind for poly-extreme environments and allow an assessment of their stability under changing climate and their potential relevance in terms of greenhouse gas release.