The protective role of cyanobacteria on soil stability in two Aridisols in northeastern Iran

Structure of cyanobacteria crusts are contained of a variety of species that having a range of attributes which contributed to their resilience and survival in arid and hyper-arid environments. Extracellular polymeric substances (EPS) produced by cyanobacteria have adhesive attributes that binds non-aggregated soil particles into a protective encrusted surface and reduces the destructive effects of wind and water erosion. In this study, we wanted to analyze the importance of soil cyanobacteria on soil stability over different landforms. To do this, we firstly was identified native and dominant cyanobacteria species, we measured different soil physicochemical properties related to soil stability and we explored the relationship between soil characteristics, stability and cyanobacteria presence. We found that cyanobacteria are able to colonize stable soils under arid conditions. However only few tolerant species were found on saline soils. Cyanobacteria promoted soil organic carbon and nitrogen. Moreover, EPS secreted by cyanobacteria increased soil water content and blind soil particle together, forming aggregates and increasing surface stability.The manuscript was part of the research project, funded by the Ferdowsi University of Mashhad (Project number: 2-43113)