Linking Microbial Diversity and Functions across Scales and Ecosystems

Ecosystems are threatened and transformed at unprecedented rates from local to global scales due to the ever- increasing human footprint that has initiated the Anthropocene. Increasing globalisation of human affairs massively changes our Planet's biodiversity, and this trend is expected to continue over the coming decades. Human impacts on biodiversity take place against a background of highly complex ecological processes that were shaped over evolutionary times. Recent research recognises the consequences of biodiversity loss for the services and goods ecosystems provide to humans, such as food production, the maintenance of water quality and soil fertility, carbon storage, the mitigation of the effects of greenhouse gas emissions and the resistance to climate and other environmental changes. Understanding how ecological, evolutionary and socio-economic factors interact to determine biodiversity and ecosystem functioning across scales is therefore a major scientific challenge of the 21st century.

MICDIF aims at elucidating the significance of microbial diversity on ecosystem functioning by explicit coupling of microbial ecology and community structure to biogeochemistry. Despite considerable advances in biodiversity research during the past decade, which primarily dealt with plants and animals, there is an urgent need to further develop the functional role of microbial biodiversity in ecosystems.

MICDIF entails intensive theoretical work involving cutting-edge expertise from molecular biology, environmental microbiology, genomics, biogeochemistry, and advanced mathematical modelling. Rather than studying terrestrial and aquatic ecosystems in isolation, we also focus on the functional interactions across these ecosystems. This cross-system approach requires profound terrestrial and aquatic expertise. We will gradually move from simple mesocosms to more complex experimental systems, and in a last phase, we will transpose experimental knowledge to the field (the "real world"). Mathematical modelling will serve as a backbone that accompanies our experimental research at any given stage and will relate the microbial world to biogeochemical models differing in scale and societal relevance.

Research that aims to unravel the topology of causation between microbial community structure and ecosystem functioning across scales is necessarily interdisciplinary and requires a long-term basis. We believe that a National Research Network (NFN) offers the most promising platform to successfully achieve our research goals. Our proposal joins internationally leading experts in Austria, integrates related national (FWF, WWTF) and international (EU, ESF) research initiatives and will therefore achieve the critical mass to further develop and strengthen innovative and internationally competitive biodiversity - ecosystem function research in Austria.