Relationship Between Soil Bacterial Diversity and Vascular Plant Richness Along a Degradation Gradient in the Jos Plateau Montane Ecosystem

The relationship between belowground microbial diversity and aboveground plant diversity is a fundamental but poorly understood dimension of montane ecosystem function in Nigeria, and this study addresses this gap for the Jos Plateau. This study examined the relationship between soil bacterial community diversity and vascular plant species richness along a degradation gradient in the Jos Plateau montane ecosystem in Plateau State. Vegetation plots (20m x 20m) and corresponding composite soil samples were collected from 24 sites distributed across four degradation levels: intact montane forest, moderately disturbed woodland, recovering farmland fallow, and actively cultivated fields. Vascular plant species richness and functional group composition were recorded. Soil bacterial diversity was assessed using 16S rRNA amplicon sequencing (MiSeq Illumina platform), with alpha diversity measured by observed operational taxonomic units, Shannon index, and Chao1 richness estimator. Beta diversity was assessed using Bray-Curtis dissimilarity. Canonical correspondence analysis explored soil bacterial community-plant community relationships. Results showed a significant positive correlation between soil bacterial Shannon diversity and vascular plant species richness (r = 0.74, p < 0.001). Beta diversity of bacterial communities tracked plant community compositional change along the degradation gradient. Intact montane forest soils showed the highest bacterial diversity (Shannon index mean: 6.82) and greatest plant richness (mean: 48 species/plot). Cultivated field soils had significantly depleted bacterial diversity (mean: 5.14) and fewest plant species (mean: 12). Canonical correspondence analysis identified soil pH and organic carbon as shared drivers of both diversity components. The study recommends dual monitoring of soil bacterial and plant diversity in Jos Plateau ecosystem health assessments. Keywords: soil bacteria, 16S rRNA amplicon sequencing, plant species richness, Jos Plateau, degradation gradient