Characteristics of spatial distribution of soil organic carbon in mangrove wetlands at the estuary of Maoling River, Beibu Gulf

In this study, the vertical and horizontal distribution characteristics of 0-60 cm soil organic carbon were analyzed in the Maoling River estuary of Beibu Gulf, where Sonneratia apetala, Aegiceras corniculatum, Cyperus malaccensis, and bare flat were studied, The influence of tidal creek on the spatial distribution pattern of soil organic carbon was also explored. The results showed that the soil organic carbon content of 0-60 cm was 6.12-51.06 g/kgmean value (28.41±8.80) g/kg. The highest soil organic carbon content was Sonneratia apetala, which ranged from 14.30-78.30 g/kgmean value (37.94±6.46) g/kg, followed by Aegiceras corniculatum, and the smallest in bare flat (3.50-36.10) g/kg, with a mean value of (9.42±3.64) g/kg. The average soil organic carbon content in the vertical direction was Sonneratia apetala>Aegiceras corniculatum>Cyperus malaccensis>bare flat. The maximum values of organic carbon content were found at 40-60 cm for Sonneratia apetala and Aegiceras corniculatum, and at 0-10 cm for Cyperus malaccensis and bare flat. From the forest interior to the forest edge, the overall organic carbon content of Sonneratia apetala soil showed a gradual decrease. Within the study area, tidal channel flume is an important factor influencing the distribution of organic carbon in mangrove soils.