Evaluating Litter Yield and Decomposition for Re-Vegetated Mangroves in a Subtropical Mudflat

Field monitoring and incubation experiments were conducted to evaluate the litter yield and examine the decomposition of the litter of three representative mangrove species frequently used for mangrove re-vegetation in a subtropical mudflat on the South China coast. The results show that the litter yield of the investigated mangrove species varied significantly from season to season. The annual litter production was in the following decreasing order: Heritiera littoralis > Thespesia populnea > Kandelia obovata. Initially, rapid decomposition of easily degradable components of the litter materials resulted in a marked weight loss of the mangrove litter. There was a good linear relationship between the length of field incubation time and the litter decomposition rate for both the branch and the leaf portion of the three investigated mangrove species. Approximately 50% or more of the added mangrove litter could be decomposed within one year and the decomposed litter could be incorporated into the underlying soils and consequently affect the soil carbon dynamics. An annual soil carbon increase from 2.37 to 4.64 g/kg in the top 5 cm of the soil was recorded for the investigated mangrove species.