Abstract: In August 2013, a quantitative survey of types, coverage and thickness of biological soil crusts (BSCs) at east, south, west and north areas under Artemisia ordosica canopy in different degradation stages was carried on re-vegetation area established in 1990 in the Tengger Desert. The results showed that there are 3 types crusts appeared around the A. ordosica was algae crust, lichen crust and moss crust, respectively; algae crust is the most widely distributed crust type. The greatest values of BSCs coverage in reproductive ramets, semi-dead ramets and dead ramets of A. ordosica occurred in the northwest of canopy were 89.75%、98.55% and 80.40%, respectively, and the lowest values occurred in the southeast of canopy were 23.10%、35.40% and 25.44%, respectively. The greatest values of BSCs thickness of reproductive ramets, semi-dead ramets and dead ramets occurred in the northwest of canopy were 4.48mm, 6.86mm and 5.14mm, respectively, and the lowest values occurred in the southeast of canopy were 2.14mm, 3.26mm and 2.80mm, respectively. The coverage showed semi-dead ramets> reproductive ramets> dead ramets and the thickness of BSCs was showed semi-dead ramets> dead ramets> reproductive ramets. A. ordosica in different degradation stages were significantly impact on BSCs colonization and development, particularly on lichen crust and moss crust in late succession of BSCs. The micro-topography of surface landscape in arid and semi-arid regions was along with A. ordosica plant growth changing.

Key words: Artemisia ordosica, biological soil crusts, coverage, thickness