Herbaceous Plant Diversity and Soil Physicochemical Properties under Different Artificial Forests in the Bulianta Core Mine, Inner Mongolia, China

Understory vegetation constitutes an essential component of the ecosystem within the coal mining area, disclosing the correlation between plant species composition and soil properties throughout the multi-year restoration process, and offering a theoretical framework for ecological restoration and reconstruction in the northwest wind-blown sand mining area. We investigated the coupling and coordination degree between the composition of understory vegetation and soil in Pinus sylvestris forests, Hippophae rhamnoides forests, and Prunus sibirica forests at different restoration stages (5 years, 10 years, 15 years) using field survey methods and indoor separation techniques. The results clearly indicate that: (1) After 15 years of recovery, a total of 32 species of herbs appeared in different plantations, belonging to 8 families and 21 genera, of which Artemisia scoparia had the highest importance value (42.85); (2) Significant differences were observed in herb diversity, soil physicochemical properties, and their relationships among different plantations (p < 0.05); (3) The vegetation–soil coupling coordination index of the plantations was as follows: P. sibirica forest (0.5111) > P. sylvestris forest (0.5069) > H. rhamnoides forest (0.4932). The vegetation status of the H. rhamnoides forest is a state of vegetation lagging development type of intermediate-level coordinated development, while the vegetation status of the P. sibirica forest and the P. sylvestris forest is barely harmonious. The status of the P. sibirica forest and P. sylvestris forest is better than that of H. rhamnoides forests. It is essential to enhance the management measures implemented in the Bulianta mine area. Appropriate tending, particularly the regulation of soil nutrients, might be more conducive to the restoration of vegetation and the improvement of forest ecosystem services in the mining area.