Decomposition and soil biota after reclamation of coal mine spoils in an arid region

Summary We compared soil biota and buried wheat straw decomposition on sites subject to topsoiling plus straw mulch reclamation procedures 1–4 years prior to our study and on an unmined site. Rates of straw decomposition were highest on the unmined site. Decomposition rates were higher on the 1- and 2-year-old sites than on the 3- and 4-year-old reclaimed spoil. Microarthropod population densities and number of taxa were greater from decomposing straw on the unmined site and lowest from straw on the 1- and 2-year-old areas. Soil bacteria, fungi, and protozoan populations on buried straw on the oldest reclaimed sites were generally equal to those on the unmined area. Nematode populations on buried straw in the unmined site and 1- and 2-year-old reclaimed sites were similar. Populations of denitrifying bacteria were larger on recently reclaimed sites than on 3- and 4-year-old sites. Decomposition and nitrogen mineralization varied as a function of the diversity and abundance of soil microarthropods. Soil microfauna can serve as an index of soil development in a disturbed arid soil.