SOIL PHYSICAL AND CHEMICAL PROPERTIES EFFECT THE SOIL MICROBIAL CARBON, NITROGEN, AND PHOSPHORUS STOICHIOMETRY IN A MANGROVE FOREST, SOUTH CHINA

Mangrove wetland ecosystem is a coastal ecological key area that combines ecological characteristics of land and marine environments. This study examined soil carbon (C), nitrogen (N), and phosphorus (P) and their stoichiometry in three dominant mangrove species (Aegiceras corniculatum, Kandelia obovata, and Avicennia marina) distributed in the Guangxi Beilun Estuary Nature Reserve, China. Results showed that soil organic carbon (SOC) was highest in K. obovata, whereas soil total nitrogen (TN) and phosphorus (TP) were highest in A. corniculatum. The C:N, C:P, and N:P ratios in K. obovata were greater than those in the others. The microbial biomass C (MBC), N (MBN), and P (MBP) concentrations varied in ranges of 33.45-249.44 mg kg(-1), 5.17-9.17 mg kg(-1), and 0.17-0.43 mg kg(-1), respectively. Similar to soil C, N, and P stoichiometry, K. obovata had the highest MBC, MBC:MBN, and MBC:MBP values, whereas the highest MBN and MBN:MBP were found in A. marina, and the highest MBP was found in mudflats. Overall, this study demonstrated that the soil stoichiometry and soil microbial biomass responded differently to different plant communities and these differences might be accounted for by variations in the environmental conditions of the three communities.