Litter cover breaks soil water repellency of biocrusts, enhancing initial soil water infiltration and content in a semi-arid sandy land

Abstract

Soil biocrusts are an important type of surface cover in sandy ecosystems, covering about 12% of the terrestrial surface. The biocrusts affect the hydrological process of sandy land by means of inhibiting soil water initial infiltration and exchange in the topsoil, and thus hinder vegetation recovery of sandy land. This study was conducted to explore the response of the soil infiltration performance and soil water content underneath the biocrusts (dominated by lichen and moss) in litter cover. The differences in soil infiltration rate and soil water content among five treatments (bare sandy land, physical crusts, biocrusts, litter covered biocrusts, and litter crusts) in the Mu Us Desert were investigated by the single-rings infiltrometer and the oven-drying method. Results showed that the initial soil infiltration rate of litter covered biocrusts and litter crusts were 215% and 280% higher than that of biocrusts. The average soil water content in litter crusts (11.7%) and litter covered biocrusts (10.2%) were 3.3 and 2.9 times greater than that in biocrusts, respectively. Our results indicated that litter cover could break the water repellency of biocrusts, increase the initial soil infiltration rates, and increase the soil surface water content. This criterion will help promote ecological restoration in sandy ecosystems.