Plant litter crust appear as a promising measure to combat desertification in sandy land ecosystem

Abstract

Desertification is one of the most alarming forms of land degradation that threatens the functioning of dryland ecosystems. Ecological restoration of ecosystem functioning in sandy land has become a worldwide urgent research issue. In this study, the effects of plant litter crust (plant litter from poplar leaves of the surrounding area and sand grains bonded together due to interaction of water erosion and wind erosion) on surface soil properties and the loamification process of sandy soil were assessed in a semi-arid sandy land ecosystem at the edge of Mu Us sandy land by the field experiment sampling and indoor analysis. Soil structure and nutrient content were measured at two depths (0–5 cm and 5–10 cm) of bare sandy soils (as control), the soils beneath of the biological soil crust and the three stages of plant litter crusts (1-, 3- and 5-years old). We found that plant litter crust cover significantly improved soil structure and soil moisture through increasing soil macro-aggregates, clay and silt sized grains content, and total soil porosity, and decreasing soil temperature. Significant differences were observed in the content of total nitrogen and available soil phosphorous and potassium among the different types of crust and bare sandy soil. In the 0–5 cm soil depth, the available phosphorous of 3- and 5-years litter curst were 71% and 94% higher than that of bare sandy soil, respectively. These results suggest that plant litter crust functioned as a driving force to promote the loamification process through modifying sandy soil surface properties. This study proves the critical role played by the plant litter crust in the ecological restoration of semi-arid sandy land ecosystem. Besides, the hypothesis that plant litter crusts have great potential in combating desertification is correct and should be considered as an appropriate measure for ecological restoration in sandy areas.