Project Details
Projekt
Carbon and energy flow in the soil microbiome – functional groups, activity and interactions in trophic networks
Subject Area
Soil Sciences
Term
since 2021
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 465081540
Soil ecosystems are driven by carbon (C), nutrient and energy flows, which are essential for biogeochemical cycles. In particular the organisms in the soil microbiome are channeling these fluxes. The interacting species are embedded within complex networks, and according to their traits, determine the architecture, stability and functionality of the micro-food web. The pattern of resource utilisation result from these trophic interactions among biota within the microbiome. The major goal of the SPP “SoilSystems” is to integrate energy-based descriptions with these biotic interactions to gain a systemic concept for turnover processes in soil. Within this framework the proposed project will link C and energy flow in the soil microbiome to the structure and function of the micro-food web, using nematodes as model group. The focus is on functional traits, life strategy and trophic interactions of microbial grazers. Using 13C labelled substrates allows for budgeting C pools and fluxes as well as stable isotope probing of phospholipid fatty acids (PLFA-SIP) and DNA (DNA-SIP). Metagenome analyses are combined with DNA-SIP to assign genes of enzymes that are involved in the degradation of substrate as well as the related metabolic pathways. Moreover, nematode metabolic footprints serve as trait-based measure for production and C assimilation of higher trophic levels. Three major questions will be addressed by the project: (1) What is the impact of functional traits of bacterial grazers (e.g. feeding mode, size) and their interspecific interactions (e.g. resource competition, intraguild predation) on C and energy flow in the microbiome? (2) How does functional complexity of grazers (i.e. multitrophic interactions) change microbial activity and metabolic transformation of resources? (3) Do altered microbial turnover processes, caused by differences in e.g., energy content of substrates, affect the structural and functional organisation of higher trophic levels? The gained morphologic, isotopic, and genomic data will be combined with metagenomic (bacteria, fungi, virome), biochemical (e.g. enzymes, ergosterol) and thermodynamic approaches (heat, calorimetry) of collaborating projects. This will provide in-depth knowledge on the structure and function of the entire microbiome, and the C and energy fluxes therein. Therewith, the proposed project will bridge the gap between species and energetic based food webs and support the understanding between energy dynamics in soil and ecosystem functions.
DFG Programme
Priority Programmes
