Forest Floor Biomass in Relation with Soil  Attributes under Pinus roxburghii Sarg.Plantation, North-East India

This study evaluated forest floor biomass dynamics and soil physico-chemical properties under a Pinus roxburghii plantation in Lumami, Nagaland, to understand ecosystem functioning and nutrient cycling. Forest floor biomass was quantified using 1 m² quadrats at monthly intervals, and soil samples were collected from three depths across autumn and spring seasons. Total forest floor biomass was estimated at ~12.6 t ha⁻¹, dominated by woody litter, followed by partially decomposed and fresh litter fractions, while herbaceous biomass was negligible. Seasonal patterns indicated higher litter accumulation during post-monsoon and summer, reflecting the balance between litterfall and decomposition. Soil properties showed clear vertical and seasonal gradients. Soils were acidic, with pH increasing with depth, while soil organic carbon was concentrated in the surface layer and declined downward. Moisture content was higher during autumn, and bulk density remained low, indicating favourable soil structure. The soils were predominantly sandy loam. The results demonstrate a strong coupling between forest floor biomass and soil properties, influencing nutrient cycling and carbon storage. However, the dominance of recalcitrant litter and surface-localized carbon suggests slower nutrient turnover and increased sensitivity to disturbance. These findings highlight the need to integrate litter and soil carbon pools in assessing the sustainability of pine plantation ecosystems.