Abstract: To explore the regional community characteristics and carbon accumulation function of mangroves in Shenzhen under different coastal conditions, the plant growth indexes, plant carbon content, soil physical and chemical properties and organic carbon of the main mangrove communities in three mangrove wetlands of Xiwan Mangrove, Dapeng Luzui Mountain Mangrove and Futian Mangrove National Nature Reserve in Shenzhen were measured, and the biomass and carbon density of different communities were compared. The results showed that Kandelia obovata, Sonneratia caseolaris, Sonneratia apetala were the constructive species, dominant species or associated species of mangrove communities in Shenzhen. The vegetation carbon density of K. obovata and S. caseolaris+S. apetala community in Xiwan mangrove was the highest, which was 88.03 t·hm^-2 and 233.56 t·hm^-2, respectively. The soil organic carbon and soil carbon density of Futian mangrove reserve were the highest (63.10 g·kg^-1, 134.65 t·hm^-2), but its soil water content and soil bulk density were significantly lower than those of the other two regions. The species composition and soil bulk density of mangrove community in Dapeng Luzui Mangrove were the most abundant, while the plant height, DBH and biomass of the community were smaller. The tree height, DBH and vegetation carbon density of S. apetala community were the highest among different mangrove communities, but its soil organic carbon content and soil carbon density were the lowest. The soil organic carbon content of Futian K. obovata wildwood was higher than that of other native and exotic mangroves. The organic carbon content of stems, leaves and fruits of 9 mangrove plants was the highest in K. obovata, and the lowest in Acanthus ilicifolius. Among the carbon contents of different organs, the fruit content of K. obovata and Bruguiera gymnorrhiza was the highest, and the organic carbon of stems and leaves of other mangrove plants was larger.

Key words: mangrove, biomass, soil carbon density, plant carbon content, Shenzhen