Responses of soil biochemical and microbial properties to vegetation combinations of quarry restoration strategies in mountainous areas in China

Abstract

The growing concern about the effectiveness of restoration strategies has spurred an evaluation of soil properties under different vegetation combinations. The restoration of underground microbial communities is critical to the success of restoration, however, the responses of biochemical and microbial properties to reclamation remain unknown. In this study, soil nutrients, enzyme activities and the characteristics of microbial communities of four restoration modes, CK1 (a non-restored mode) and CK2 (an original habitat mode) in a mining area of Sanhe City of Hebei Province were measured. Soil bacteria and fungi communities were analyzed by high-throughput sequencing of 16S rRNA gene fragment and internal transcribed spacer (ITS) to assess the recovery effects of different ecological restorations. Our results showed that: (1) The improved effect on soil available phosphorus (AP), available potassium (AK) and organic matter (OM) was obvious. Also, artificial and native plant combinations of Medicago sativa + local dominant natural vegetation (Nr) had the most obvious effect on soil nutrients. (2) The activities of soil urease, soil sucrase and soil phosphatase in Nr were considerably higher than those in other restoration modes (p < 0.05), while the soil catalase activity was the highest in the vegetation combinations of Medicago sativa + artificial miscellaneous grass (Mg) (p < 0.05). (3) Bacterial community structures in Nr were closest with those in CK2, whereas fungal community structures in Mg recovered the best. On the whole, the recovery rates of different indicators were ranked as follows: soil nutrients > bacteria > fungi. These results indicated that in the short term, native vegetation incorporating the planting of alfalfa significantly increased ecological restoration effects, however, a longer restoration history was required to restore the soil microbial diversity level similar to that of the original habitat.