Development of artificial moss-dominated biological soil crusts and their effects on runoff and soil water content in a semi-arid environment

Artificial biological soil crusts (hereafter 'crusts') are promising candidates for the control of soil and water loss in semi-arid ecosystems. However, their hydrological functions have not yet been sufficiently investigated. In this study, runoff plots were constructed in a semi-arid environment on the Loess Plateau of China, and moss-dominated crusts were later artificially cultured. The effects of the artificial crusts on runoff and soil water content (0-90 cm) over eight years (2005-2012) were determined, depending on the differences between the artificial crusts and no crusts. The results showed that (I) artificial moss-dominated crusts primarily developed after two years and fully formed after four years in the semi-arid environment; (2) artificial crusts reduced runoff by 27% in total in the first three years after the inoculation; (3) artificial crusts decreased soil water content, and this effect increased linearly with time; and (4) artificial crusts increased water content in the upper 20 cm of soils but reduced water content in deeper (>30 cm) soils. The results indicate that it is feasible to artificially culture moss-dominated crusts in semi-arid regions. However, artificial crusts only slightly improved surface soil water conditions and greatly impaired deeper soil water conditions. (C) 2015 Elsevier Ltd. All rights reserved.