Abstract: Woth the mangrove degradation phenornenon in Dongzhai harbor on Hainan Island, we set sample plots along Changning river to investigate the mangrove degradation characteristics and soil physical and chemical properties. The results showed that the mangrove community was obviously degraded. The mortality and degradation rates were significantly negatively related to the canopy coverage, and they were also negatively related to the number of respiratory roots per unit area. Degradation rate was not significantly correlated with the bulk density, capillary porosity and the total porosity of the upper soil layer (0-30 cm). However, the degradation rate was significantly correlated with the capillary porosity of the lower soil layer (30-60 cm). Moreover, the mortality rate was significantly correlated with the bulk density, total porosity and capillary porosity of the lower soil layer. Soil chemical properties were not correlated with mangrove degradation.

Key words: nutrient heterogeneity, physiological integration, photosynthesis., Zoysia japonica