Vegetation type affects soil enzyme activities and microbial functional diversity following re-vegetation of a severely eroded red soil in sub-tropical China

- Re-vegetation improved soil enzyme activities and microbial functional diversity.
- More than 18 years is needed for a complete restoration.
- Soil enzyme activities and microbial functional diversity varied with carbon input.
- Soil restored with L. bicolor performed better than P. massoniana and C. camphora.

The objectives of this study were to evaluate the restorative effects of re-vegetation and vegetation type on soil enzyme activities and microbial functional diversity of eroded red soil. Soil samples were collected by horizon from eroded soils that had been restored for 18 years with Cinnamomum camphora, Pinus massoniana or Lespedeza bicolor. Un-eroded soils planted with these vegetation types and an eroded bare soil served as references. Soil microbial functional diversity was assessed by the community-level physiological profiles (CLPP) using BioLog Eco-plates. Re-vegetation improved soil enzyme activities and microbial functional diversity, compared with the eroded bare soil. The soil restored with L. bicolor had the highest cellulase and β-glucosidase activities but the lowest urease activity. The soil restored with P. massoniana and C. camphora had the highest polyphenol oxidase activity and microbial functional diversity, respectively. The microbial functional diversity and community structure based on CLPP exhibited different patterns in O, A or B horizons. The varimax rotated component matrix of CLPP further indicated that the polymers, phenolic compounds and carbohydrates largely affected the microbial functional structure in O horizon, while amines, amino acids and carboxylic acids mainly affected the microbial functional structure in B horizon. We suggest that the enzyme activities and microbial functional diversity are determined by the quantity and quality of carbon inputs. Soil enzyme activities and microbial functional diversity as well as soil microbial biomass and physicochemical properties in the restored eroded soil did not completely recover to the levels of the un-eroded reference soil.