Litterfall dynamics and turnover in moist deciduous forests of Eastern India: implications for nutrient cycling and sustainable forest management

Litterfall and decomposition play a key role in nutrient cycling, soil fertility, and forest regeneration in tropical ecosystems. This study assessed litterfall, decomposition rates, and nutrient dynamics in three forest types: pure Sal forest (PSF), Sal-dominated mixed forest (SDMDF), and mixed forest without Sal (MDFWS). Aboveground litterfall was measured using traps, fine root litter using soil monoliths and decomposition via litterbag incubation followed by chemical analyses of organic carbon, macronutrients, lignocellulosic fractions, and phenolic content. Annual litterfall varied significantly by forest type and season, with the highest values in SDMDF (12.78 Mg ha−¹) and lowest in MDFWS (8.93 Mg ha−¹), with leaf litter contributing over 70%. Decomposition was fastest in MDFWS due to nitrogen-rich Fabaceae litter, whereas PSF showed the slowest decay owing to high lignin and C:N ratios. Decay constants (k) ranged from 2.82 to 4.75, 1.39 to 2.32 and 1.83 to 2.69 for leaf, branch and root respectively. Nitrogen, phosphorus, and potassium exhibited a tri-phasic release pattern (rapid release, immobilisation, and remobilisation), while carbon declined steadily. Moderate litter accumulation (4.16 Mg ha−¹) and rapid nutrient turnover in MDFWS supported highest seedling survival (25.9%), establishment (10,155 ha−¹), and growth. Overall the results highlight the importance of litter quality and decomposition process in driving forest regeneration.