Trade-offs Between Growth, Carbon Use Efficiency, and the Production of Extracellular Polymeric Substance and Soil Enzymes of Soil Microbes under Long-Term Warming with Different Resource Complexities

A large amount of research has demonstrated that global warming leads to changes in the structure and function of soil microbial communities. Despite the large number of studies which have identified soil microbes as key drivers of biogeochemical processes, little is known about the trade-offs between soil microbial activities under environmental change and how this will affect soil biogeochemistry.To this end, we currently develop high throughput methodology to measure growth, respiration, extracellular polymeric substance (EPS), extracellular enzyme activity (EEA) and carbon use efficiency (CUE) in pure cultures of a wide range of bacterial isolates. In response to resource quality (concentration, lability, stoichiometry), temperature and oxygen stress, we will assess trade-offs between key microbial catabolic and anabolic processes. The methodology will finally be applied to soils collected from the Achenkirch forest warming experiment in Austria to examine how complex communities and isolates from long-term warming and control soils express trait trade-offs. Isolates will be selected and checked to cover the most actively growing microbes in control and warmed soils using the qSIP method. The purpose of this study is to gain a deeper understanding of the anabolic and catabolic transitions of soil microbes under the influence of warming and, consequently, to predict the potential biogeochemical impacts of long-term warming on forest soils.