Evaluation of Soil Microbial Activity and Its Relationship with Plant Community Composition in Restored Mining Landscapes of Plateau State

Soil microbial activity is a fundamental driver of plant community recovery in restored mining landscapes, and its professional evaluation alongside plant community composition in Plateau State tin mining restoration sites provides essential feedback for adaptive management. This study evaluated soil microbial activity indicators (microbial biomass carbon, dehydrogenase activity, urease activity, and phosphatase activity) and their relationship with vascular plant community composition across three restoration age classes (0 to 3 years, 3 to 7 years, and 7 to 15 years post-restoration) in tin mining affected areas of Jos East and Barkin Ladi Local Government Areas. Vegetation plots and paired soil sampling were conducted at 18 sites. Plant community composition was assessed using standard phytosociological methods. Soil enzyme activities and microbial biomass carbon were determined using standard laboratory protocols. Pearson correlation and canonical correspondence analysis were used to assess relationships. Microbial biomass carbon increased significantly with restoration age (from 84 to 312 µg/g soil) and was strongly correlated with plant species richness (r = 0.78, p < 0.01). Dehydrogenase activity was the most sensitive indicator of early restoration trajectory. Canonical correspondence analysis revealed that phosphatase activity was the strongest environmental variable explaining plant community compositional change across the restoration gradient. Pioneer leguminous species (Tephrosia bracteolata and Leucaena leucocephala) at the youngest sites contributed disproportionately to microbial activity recovery. The study recommends microbial activity as a mandatory indicator in Plateau State mine restoration monitoring protocols alongside plant community composition. Keywords: soil microbial activity, plant community, mining restoration, Plateau State, dehydrogenase