Changes in relationships between initial litter quality and CO2 release during early laboratory decomposition of tropical leaf litters

The relationships between initial litter quality with respiration during the early stage of decomposition was investigated in the litters of different tropical species from natural and planted fallows, and from tree plantations. CO2 release was measured at 1- to 6-d intervals during 21 d. No significant relationship was found between total CO2 release and any initial compound content, The rate of respiration versus time showed two stages. During the first stage, CO2 release rate was high and appeared to be negatively related to polyphenols, suggesting an inhibition. During the second stage, CO2 release rate was lower and was positively related to water-soluble phenolics, and to the soluble C/soluble N ratio. Total nitrogen add lignin content did not exhibit any effect on the respiration rate at this stage. (C) Elsevier, Paris.