Soil organic carbon (SOC) figures prominently in greenhouse gas and carbon (C) mitigation projects, thus significantly affecting the global C cycle. How is the soil C storage and its spatial pattern in mangrove wetland? This study examined soil in mangrove wetlands of Qinglan Harbor in Hainan Province, China, using multi-point line surveys to sample soil in different mangrove communities and at 3 defined tidal zones for subsequent laboratory measurement of variations in Soil C storage with soil depth, community type, and tidal zone.
Results/Conclusions
We found that Soil C storage increased with increasing soil depth in Lumnitzera racemosa plots but decreased in Sonneratia alba plots. In Bruguiera sexangula plots, Soil C storage first increased with soil depth and then decreased. In high and mid tidal zones, Soil C storage was greatest in the Sonneratia caseolaris community, less in the Lumnitzera racemosa community and the least in the Sonneratia alba community. Regardless of which tidal zones the studied mangrove communities occupied, Soil C storage was greater in the lowest tidal zone that a given community occupied and decreased with higher tidal zones throughout the communities. Mean Soil C storage of 0-90 cm soil cores was 23.33 kt/km2. Our study showed that Soil C storage in a mangrove wetland varied with both soil depth and plant community type and differed between tidal levels.