Towards stopping land degradation in drylands: Water‐saving techniques for cultivating biocrusts in situ

Abstract

AbstractIn recent years, inoculating sand surfaces with biocrust organisms has become one of the most promising biotechnological strategies for controlling and reversing land degradation in drylands. To fully exploit this biotechnology on a large scale in drylands, researchers must explore water‐saving techniques to incubate biocrusts in situ. To achieve this aim, we tested three methods—broadcasting dried cyanobacteria, spraying fresh cyanobacteria, and broadcasting natural biocrust fragments—to culture biocrusts in situ on the Tengger Desert in Northern China. The cover of incubated biocrust increased during the first 2 months after inoculation (from 6% to more than 20.0% in treatments using biocrust fragments); biocrust cover declined but persisted after 12 months of incubation (13.8% cover in the best treatment, natural cyanobacteria fragments). The cover of cyanobacteria was higher than the cover of lichen in our natural cyanobacteria‐lichen crust fragment treatment (NCL; p < .05) after incubating for 12 months. We highlight that cyanobacteria should be selected for biocrust incubation during the initial stages of dryland restoration. Accumulated rainfall was positively related to the cover of incubated biocrust. However, wind speed and wind erosion intensity were both negatively related to the cover of incubated biocrust. In conclusion, broadcasting biocrust fragments is a rapid, efficient, and water‐saving biotechnique to cultivate biocrusts in situ. Actions to reduce wind speed and wind erosion, such as mechanical sand fixing, can help stabilize soils and improve crust cultivation.