Influence of Species, Stand Age and Seasonal Dynamics on Soil Microbial Biomass Carbon in Restoring Limestone Mine

DOI: 10.22161/ijeab.106.10

Abstract:
This study evaluates the impacts of plantation species, stand age, and seasonal variation on soil microbial biomass carbon (MBC) in the restoration of degraded limestone mine soils at the Nandini Limestone Mines, Chhattisgarh, India. Four plantation species namely Dalbergia sissoo, Azadirachta indica, Tectona grandis, and Albizia procera were analyzed across three chronosequence ages (5, 15, and 25 years) and three seasonal periods (pre-monsoon, monsoon, and post-monsoon) at 15–30 cm soil depth. Soil microbial biomass carbon increased significantly with plantation age across all species, with Dalbergia sissoo demonstrating superior recovery from 62.85 ± 3.71 µg C g⁻¹ at 5 years to 99.34 ± 8.03 µg C g⁻¹ at 25 years (pre-monsoon), while monsoon peaks reached 117.64 ± 4.99 µg C g⁻¹. Seasonal patterns revealed dramatic moisture-driven increases, with monsoon MBC values (70–130 µg C g⁻¹) approximately two-fold higher than pre-monsoon values (40–110 µg C g⁻¹). Three-way ANOVA analysis revealed that plantation age (F₂,₇₂ = 137.87, p < 0.001), season (F₂,₇₂ = 57.67, p < 0.001), and species identity (F₃,₇₂ = 33.75, p < 0.001) all exerted significant main effects on MBC, with plantation age accounting for 47.4% of total variance, season explaining 19.8%, and species identity explaining 17.4%. All two-way and three-way interaction terms were non-significant (p > 0.36), indicating additive rather than synergistic effects. Despite substantial improvement, MBC values in 25-year plantations (mean 100 µg C g⁻¹) remained 40% depleted relative to undisturbed reference soils (157.59–170.56 µg C g⁻¹). The model explained 84.7% of total variance with minimal residual error (12.4%), demonstrating robust predictive capacity for restoration trajectories. Results demonstrate that integrating fast-growing, high-quality litter species like Dalbergia sissoo and Azadirachta indica with moisture-conserving amendments offers a promising strategy for accelerating microbial and ecosystem recovery in degraded limestone mine landscapes.

Keywords:
Soil microbes, soil carbon, biomass carbon, limestone mine, restoration.

Article Info:
Received: 21 Oct 2025; Received in revised form: 18 Nov 2025; Accepted: 26 Nov 2025; Available online: 04 Dec 2025

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