Assessing Plant-Microbial Interactions and Organic Matter Composition in European Peatlands

Peatlands are among the most carbon-dense terrestrial ecosystems, holding approximately one-third of the global soil carbon despite covering only a small percentage of Earth's land area. However, their ability to act as carbon sinks is under threat from widespread warming and associated climate changes, which may disrupt the intricate ecological processes underpinning their functioning as carbon sinks.

Plant and microbial community interactions are central to peatland functioning, driving both primary production and decomposition, the key processes influencing carbon sequestration. Environmental and climate fluctuations often alter these community assemblages, potentially reshaping plant-microbial networks and their complexity. Despite their significance, the responses of these networks to enviro-climatic changes remain poorly understood.

To address this gap, we evaluated plant-microbial networks in fifteen European peatlands spanning a climatic and enviro-climatic gradient (incl. temperature, precipitation, nutrient deposition). Using vegetation and microbial composition data, we assessed changes in diversity within plant and microbial communities, plant-microbe networks structure, and network complexity along this gradient. Additionally, we link plant-microbe network topological characteristics to organic matter – detailed by Fourier-transform infrared (FTIR) spectroscopy – to assess the role of plant-microbe interaction on carbon cycling processes.

Preliminary analyses reveal that vegetation composition exhibits limited variation across the climate gradient, whereas microbial communities show pronounced differences. Our findings underscore the potential role of microbial communities as key drivers of ecosystem responses to environmental change, suggesting that shifts in microbial composition could have significant implications for the peatland carbon sink function under future climate scenarios.