Abstract: During August to September of 2012, a survey on coverage and thickness of biological soil crusts (BSCs) was carried on a dumping site in the open pit coal mine of Heidaigou in Inner Mongolia. Fifteen woody plots with a size of 10 m × 10 m, 45 herbage plots with a size of 1.0 m × 1.0 m and 150 biological soil crusts plots with a size of 0.2 m × 0.2 m were set under five re-vegetation types of arbor, arbor + shrub, arbor + herbage (Gramineae), arbor + herbage (Leguminosae) and abandoned farmland. The results showed that the total coverage of BSCs was more than 50% under each of the five re-vegetation types. The algae crust coverage under arbor and arbor + herbage (Leguminosae) re-getations was 56% and 43%, respectively, being higher than under other re-vegetation types. The moss crust coverage under arbor + herbage (Gramineae) re-vegetation was 34%, being higher than under other re-vegetation types. The thickness of BSCs under arbor + shrub re-vegetation was 0.55 cm, being higher than under other re-vegetation types. Vegetation restoration is beneficial to BSCs colonizing and growth at the dumping site of the open pit coal mine, and re-vegetation types and vegetation coverage significantly influence BSCs coverage and thickness.

Key words: chelate resin, preconcentration, platinum group element, speciation, trace, seawater.