Litter production and litter elemental composition in two rehabilitated Kandelia obovata mangrove forests in Jiulongjiang Estuary, China

Spatial and seasonal variations in litter production and C, N, and P concentrations were compared between the 24 and 48 year old Kandelia obovata mangrove forests in the Jiulongjiang estuary, China. The 24 yr forest had significantly higher production of total, leaf and branch litter, but lower flower and fruit litter than the 48 yr forest. Total, leaf and branch litter production were significantly positively correlated to monthly temperature and rainfall. Spatial patterns of litter production among the inner, mid and outer zones in the same forest were similar to those of tree heights. C, N and P concentrations of leaf litter showed significant seasonality but varied little among these three forest zones. C/N and N/P ratios of leaf litter were significantly lower for the 24 yr forest than those for the 48 yr forest. During the entire sampling year, total litter of the 24 and 48 yr forests contained 590.31 and 437.31 g C m−2 yr−1, 8.46 and 5.47 g N m−2 yr−1, 1.92 and 1.16 g P m−2 yr−1, respectively.

► 24 yr Kandelia obovata forest produced more total, leaf and branch litter, but less flower and fruit litter than 48 yr forest.
► 24 yr K. obovata forest had significantly higher N and P concentrations of leaf litter than 48 yr forest.
► C, N and P concentrations of K. obovata leaf litter had significant seasonality with high values in cold months.