When restoring dryland ecosystems, growing biological soil crust (biocrust) may greatly change the redistribution of rainfall in layered soil. However, ecohydrological modelling studies generally ignored biocrust, and thus the ecohydrological effects of biocrust on restorations remains largely unexplored. With a long-term restoration case (located in the southeast edge of the Tengger Desert, northern China), we developed an ecohydrological model with explicit consideration of the infiltration in three layered soils (biocrust, shallow and deep sand layers) to investigate influences of biocrust on restoration dynamics in drylands.
Results/Conclusions
The infiltration in ‘annual’ layer (including both biocrust and shallow sand layers, 0 – 30 cm) and ‘shrub’ layer (30 – 150 cm) with biocrust significantly increased and decreased relative to values without biocrust, respectively. Meanwhile, biocrust significantly decreased soil water content in deep sand layer, while not shallow sand layer. As more water was used by transpiration against evaporation, the ecosystem with biocrust reached a final state of grass-dominated state (high grass cover of 40%, low shrub cover of 4%) rather than shrub-dominated state (grass cover of 2%, shrub cover of 20%). This study suggests that we need to account for the roles of biocrust on rainfall infiltration to better understand vegetation and restoration dynamics in dryland ecosystems.