Variations in cyanobacterial and algal communities and soil characteristics under biocrust development under similar environmental conditions

Aims Cyanobacterial and algal communities have a large effect on biocrust formation and development. Biocrust species and abundance vary spatially and temporally due to different environmental factors. The relationships among cyanobacterial and algal communities, and biocrust function have been studied extensively. Lacking, however, are studies of temporal changes in a similar landscape where environmental conditions are similar, but where biocrust formation is different. Methods Biocrusts of different ages were located in the Loess Plateau in an area that had experienced a landslide. We examined changes in cyanobacterial and algal communities, carbon, nutrients, and the composition of dissolved organic matter in the topsoil, and the relationships among the community and soil characteristics using redundancy analysis. Results Phormidium tenue (Cyanophyta) dominated in all biocrusts, and co-dominated in a newly formed crust with Euglena sp. (Euglenophyta). Oscillatoria sp. (Cyanophyta) increased with biocrust age. Oscillatoria was positively correlated with carbon fixation and nutrient (nitrogen and phosphorus) accumulation in topsoils. Conclusions While incubation of Phormidium tenue and Euglena sp. is suggested for rapid biocrust formation at an early stage, increasing the abundance of Phormidium tenue and Oscillatoria sp. can promote carbon fixation and nutrient (nitrogen and phosphorus) accumulation, thereby accelerating biocrusts into a later stage.