Leaf litter decomposition and soil mesofauna contribution in Pisonia grandis and Guettarda speciosa plant communities in the Yongxing Island of South China Sea

Coral island is the major terrestrial ecosystem type in South China Sea. Litter decomposition is a key biogeochemical process that drives ecosystem nutrient cycling, but has not been studied in these coral islands. We set up three quadrats in each of the two plant communities dominated by Pisonia grandis and Guettarda speciosa in the Yongxing Island of South China Sea. Decomposition litterbags were deployed in the quadrats in July 2018 to quantify the litter turnover rate and nutrient release pattern. The decomposition experiment lasted for 15 months till October 2019 and we sampled 5 times within the period to weigh remaining litter mass and to analyze the chemical constitutes of the decomposing litter. The analyzed chemical elements included total carbon (TC), total nitrogen (TN), total phosphorus (TP), lignin, cellulose,