BayCEER Workshop 2022

Warming induced changes in the microbiome and carbon dynamics in the soil-plant-system of Vaccinium vitis-idaea

Plants exude up to 20% of the recently assimilated carbon into the rhizosphere, which partly leads to microbially mediated C-stabilisation in the soil. Understanding of temperature dependencies during this process and thus, the effect of global warming are scarce. We hypothesize that i) the flow of recently assimilated carbon into organic layers and soil increases with temperature, ii) microbiome composition and activities change with temperature, leading to iii) an accumulation of C in microbial biomass and specifically in C stabilizing organisms with higher temperature.

To investigate these questions, we conducted a translocation experiment in Finland exposing Lingonberries (Vaccinium vitis-idaea) and its underlaying soil to a higher temperature (+ 4 °C MAT). After three years, we applied ¹³CO₂-pulse labelling and are now analysing the δ¹³C in the soil (organic layer, mineral soil, and rhizosphere), the gas phase, and the plant. In parallel we use different methods to characterize the microbial composition and activity (16s rRNA, PLFA, chloroform-fumigation-extraction, staining to count the mycorrhizal infection, and respiration analysis). Ultimately, we will analyse the δ¹³C in the total microbial biomass and selected functional groups.

The experiments are ongoing and the latest, preliminary results will be presented.