Litter decomposition and nutrient release dynamics under Swietenia macrophylla King plantation in the Indian sub-Himalayan region

Litter decomposition plays a pivotal role in the functioning of various ecosystems in the form of recycling nutrients. Comprehensive studies on nutrient cycling are a vital concern in the context of increasing anthropogenic imprints on bio-geochemical cycles. Present study was conducted for one year (2017-2018) under 13 years old broad leaf mahogany plantation in the sub-Himalayan region of West Bengal, India. The standard litterbag technique was used to study the decomposition and nutrient release pattern of litter. Results indicated that leaf litter had higher nutrients concentration than rachis litter except C and lignin. After one year of decomposition, an average weight of 4.33 g (21.64%) and 5.01 g (25.05%) remained in leaf litter and rachis litter, respectively. Decomposition was accelerated by warm temperature, high humidity, and enriched litter nutrient status. From the mineralization kinetics, it was noted that the decomposition rate constant (k) of leaf litter was higher than that of rachis litter. The recorded k for the first month's decomposition of leaf litter was 0.372 month(-1) and 0.114 month(-1) for rachis litter. Half-life (T-0.50) value for leaf litter was 1.868 months and 6.075 months for rachis litter. Nutrient release of nitrogen (N), phosphorous (P) and potassium (K) were observed to be 20.91 and 20.48 kg N ha(-1) ton(-1); 1.46 and 0.95 kg P ha(-1) ton(-1); 14.50 and 7.69 kg K ha(-)1 ton(-1) from leaf and rachis, respectively. The average soil pH, EC, and bulk density (BD) values indicated significant variations with increasing depth as well as comparing plantation to non-plantation sites. The plantation site almost displayed higher mean total organic carbon (TOC), N, P, and K values than non-plantation sites. The present findings can serve as baseline information for future tree-based interventions in diverse land use systems management.