Ecological facilitation in soil microbial communities. Ecological facilitation in soil microbial communities

Biological soil crusts (biocrusts) cover about 12% of the Earth’s land masses, thereby providing ecosystem services and affecting biogeochemical fluxes on a global scale. They comprise photoautotrophic cyanobacteria, algae, lichens and mosses, which grow together with heterotrophic microorganisms, forming a model system to study facilitative interactions and assembly principles in natural communities. According to the predominating photoautotroph, they are broadly categorized into cyanobacteria-, lichen-, and bryophyte-dominated crust types, reflecting stages of ecological succession. The aim of the current study was to examine whether these categories also include a shift in heterotrophic communities and whether this may be linked to altered physiological properties. Thus we analyzed the microbial community composition of different biocrust types and bare soil by means of qPCR and high-throughput amplicon sequencing and utilized flux measurements to investigate their physiological properties.