Explaining trajectories of chemical changes during decomposition of tropical litter by ¹³C-CPMAS NMR, proximate and nutrients analysis

• Published in: Plant and soil Vol. 436; no. 1/2; pp. 13 - 28
• Main Authors: Sarker, Tushar C., Maisto, Giulia, De Marco, Anna, Esposito, Francesco, Panico, Speranza C., Alam, M. Firoz, Mazzoleni, Stefano, Bonanomi, Giuliano
• Format: Journal Article
• Language: English
• Published: Cham Springer Science + Business Media 01.03.2019; Springer International Publishing; Springer Nature B.V
• Subjects: Biomedical and Life Sciences; Carbon; Carbon 13; Carbon cycle; Cellulose; Decomposition; Ecology; Iron; Leaf litter; Life Sciences; Lignin; Magnesium; Magnetic resonance spectroscopy; Manganese; Nitrogen; NMR spectroscopy; Nutrient cycles; Nutrients; Organic carbon; Organic chemistry; Phosphorus; Plant Physiology; Plant Sciences; Potassium; REGULAR ARTICLE; Sodium; Soil Science & Conservation; Trajectories; Tropical forests; Zinc; C/N ratio; Proximate features; Tropical litter; Decomposition; Nutrients dynamics
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-018-03907-9

Background and aim Litter decomposition is of great concern as it plays a key role in regulating global carbon cycle and nutrient budgets, especially in tropical forests where it is very fast. Therefore, we studied the decomposition and subsequent changes in element concentrations and amounts of 11 tropical leaf litter. Methods Fresh litters were characterized in terms of elemental, proximate features, as well as organic carbon compositions by 13 C-NMR spectroscopy. Controlled litterbag decomposition was carried out for 180 days in the laboratory, bags were retrieved at three dates and analyzed for mass loss and concentration of nitrogen (N), potassium (K), sodium (Na), carbon (C), magnesium (Mg), manganese (Mn), iron (Fe), phosphorus (P), zinc (Zn), and percentage of ash, extractives, cellulose and lignin. Results Terminalia arjuna showed highest mass loss , while the lowest was observed in Shorea robusta showing significant positive correlation with litter initial K, Mg, Fe and di-O-alkyl C, O-alkyl C, while significant negative correlation with Mn, lignin and Methoxyl C, Alkyl C. Trajectories shows that Fe, Mg, K, Mn, Zn and Na concentrations increased in most of the litter types, except Terminalia arjuna and Toona ciliata, where Fe, Mg, K concentrations decreased during decomposition. Surprisingly, in most of the species with the exception of Terminalia arjuna , N concentrations decreased at a faster rate than C concentrations, resulting in an increase in C/N ratios. Expectedly, lignin progressively increased, while cellulose decreased. Conclusions Observed differences in decomposition rate and dynamics of chemical changes among litters were strongly affected by the litter type, decomposition time and their interactions.