Project Details
Projekt
Live/Dead: Contribution of soil protists to carbon cycles through microbe predation and necromass
Subject Area
Microbial Ecology and Applied Microbiology
Soil Sciences
Soil Sciences
Term
since 2025
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 554770703
Protists represent most of the eukaryotic diversity in soil, with cell numbers that can reach hundreds of thousands and more per gram of soil, and a wide range of functional groups that are closely intertwined with terrestrial carbon fluxes (i.e., heterotrophs, saprotrophs, and even phototrophs); however, their role in carbon cycling in life, as microbial predators, and especially in death, as microbial necromass (NM), remains virtually uncharacterized. Leveraging the framework of the SPP SoilSystems, this project will explore the role and contribution of protistan predation and protistan NM to soil carbon fluxes. In a set of controlled microcosm experiments, we will first characterize the consumption of protistan NM relative to fungal and bacterial NM by the soil microbiome. Through DNA-SIP with 13C-labelled protistan necromass, we will identify organismal preferences and track carbon transfer within the soil microbial trophic networks for different NM pools. Through calorimetry, we will explore how protistan NM contributes to soil energy fluxes relative to the better-known bacterial and fungal NM pools. In a second microcosm experiment, we will explore whether soil organic matter content as an important boundary condition affects consumption of protistan NM by soil microbiota and their networks. Finally, as part of the joint experiment Functional Complexity, we will identify how soil management modulates soil protistan communities, how the complexity of these communities contributes to emergent properties of the soil microbiome (i.e., resistance and resilience) through predation, and determine whether protistan community dynamics following disturbance affect carbon cycling across a complexity gradient. Taken together, these experiments, which will be conducted collaboratively within the SPP consortium, will address hypotheses A-C of SoilSystems while providing the most comprehensive analysis to date of the contribution of living and dead protists to the soil carbon cycle and energy fluxes.
DFG Programme
Priority Programmes
