Biomineralized sand facilitates the structural development of cyanobacterial biocrust

Abstract

Land degradation is a global problem, and effective land restoration techniques are needed. The introduction of biocrust has attracted much attention because biocrust-forming organisms have a high survival rate in harsh environments and perform various ecological functions. However, physical disturbances and low water resources impede biocrust development. In degraded areas, soil tackifiers and amendments are often applied before biocrust inoculation, but optimal methods require further research. This study examined whether biomineralization by ureolytic bacteria, one soil stabilization method, could facilitate the growth of biocrust-forming cyanobacteria and biocrust development by improving soil stability and water retention. We incubated cyanobacterial biocrusts on biomineralized sand layers, bare sand, and sand with calcium carbonate powder and, measured indicators of biocrust development, soil stability, and water infiltration. Biomineralization with the biocrust had no effect on water infiltration but improved soil stability. Biomineralization did not significantly facilitate cyanobacterial growth but did improve biocrust structure development. Our findings indicate that biomineralization can enhance the biocrust structure at least in the short term. Longer experiments are needed to clarify the negative aspect of biomineralization on cyanobacterial growth.