A review on the development and effect of biological soil crusts

Biological soil crusts are widely distributed in arid and semiarid regions, occupy approximately 40% of the total land area, and determine the main biological surface characteristics of the ecological system, thereby playing an important role in improving the ecological environment and the meadow soil nutrient regulation. Since 1960, many experts worked a lot on its ecological functions at the domestic and international levels, but soil nutrients variation characteristics and microenvironmental processes of biological soil crust development remain unclear. Therefore, this paper which based on the domestic and international research progress and achievements in this field over 50 years, had detailed a lot. In order to provide a comprehensive understanding of biological soil crusts development on the cycling process of soil fertility; further, it provides suggestions for ecosystem restoration in the degraded grasslands of the Loess Plateau, China.