Contribution of biological soil crusts to soil organic matter composition and stability in temperate forests

Biological soil crusts (biocrusts) play an important role in the biogeochemical C-, N- and P-cycles but there is limited knowledge about their effect on composition stability of organic matter (OM) soil. In pine beech dominated temperate forests, different compartments biocrust, crust-adhering crust-free were analysed by pyrolysis field ionization mass spectrometry (Py-FIMS) C K-edge X-ray absorption near edge structure (XANES) spectroscopy. Phototrophic biocrust communities had been determined morphologically. Predominant tree species affected OM overriding organisms was observed. biocrusts, mineralization potential high due to a carbohydrate/ketone ratio proportion fatty acid C22:0. A free acids combination with carbohydrate identified as relative marker for biocrusts additional proportions lignin dimers specific samples under pine. pine, characterized large long-chain aliphatics from plant cuticular material. A-horizon substrate beech, compound classes not phototrophic richness, suggesting functional redundancy these regard composition. contrast substrate, C-horizon higher easily decomposable Under forest management intensity (SMI) stand age density effects species. We conclude that compartment, vegetation, horizon SMI stability, hence contributed diversity ecosystems.