Effects of biological soil crust on desert insect diversity: Evidence from the Tengger Desert of northern China

Biological soil crusts are widespread in arid and semiarid regions. They are one of the major components of desert ecosystems, and their importance has been demonstrated by numerous researchers. However, little research has been carried out on the relationship between biological soil crusts and the diversity of desert insects. In this study, psammophilous Caragana korshinskii-Artemisia ordosica communities occurring on semifixed dunes and fixed dunes in the Shapotou region at the southeastern fringe of the Tengger desert are investigated. Observation sample plots and the survey quadrats were arranged in the vegetation areas with different types and coverage of biological soil crusts. The insects were surveyed in 10 m x 10 m quadrats and caught by a sampling frame and net-trap methods. The insect number was recorded and samples were collected for identification. The results show that as compared to the un-crusted vegetation area, the presence of biological soil crusts in the Tengger desert significantly increases the diversity and abundance of insect species. Diversity and abundance in the quadrats mainly covered by moss and lichen crusts are significantly higher than those in the quadrats mainly covered by cyanobacteria and algal crusts. The contribution of biological soil crusts to the diversity of insect species may be attributed to the stabilized soil surface providing suitable habitats and some food sources for the insects.