Study on the Characteristics of Litter Production and Decomposition in Plantations of Eucalyptus grandis in Rainy Area of West China

Litter production,decomposition and nutrient release were investigated in a Eucalyptus grandis plantation in Rainy Area of West China.The results showed that: ① The annual litter production was 6 247.78 kg/hm2 in this eucalyptus plantation,leaf litter account for 94.85% of the total production,followed with twig and bark.② The leaf litter had higher decomposition rate than twig litter.39.56% of leaf litter and 56.35% of twig litter remained after 12 months decomposition,The decomposition rate in leaf litter was higher from the 5th month to the 8th month,but which in twig litter was higher from the 4th month to the 10th month compared with other decomposition stages.It would take 2.989 years and 4.783 years to decompose 95% of leaf litter and twig litter,respectively.③ After 12 months decomposition,elements release rates showed the order as: NCPK for leaf litter,and CNKP for twig litter.Elements release rates in leaf litter were higher than those in twig litter.④ The initial C/N ratios in leaf and twig litters were 43.51 and 285.78.The C/N ratios showed a decreasing trend as leave and twig litter decomposition proceeded.