Abstract: The structural characteristics, species diversity and succession of Heritiera littoralis community in Baguang, Shenzhen were comprehensively investigated by the transect method. The protection status of the ancient trees within this community was also evaluated. Based on the habitat characteristics, this community could be classified into three habitat groups and the diversity and succession tendency of each group were analyzed. Results showed that a total of 89 woody species, belonging to 35 families and 73 genera, were recorded. Among them, H. littoralis had the highest importance values in the arbor, sapling and seedling layers, followed by Cinnamomum burmanni, Psychotria rubra and Cerbera manghas, which also had high importance values. Saplings with a height less than 2.5 m occupied 83.26% of total individuals, among which, 78.37% was H. littoralis, indicating that the succession pattern of H. littoralis followed the pyramidlike tendency. The community in the habitat group adjacent to sea (seaward habitat) had the highest diversity index, followed by the habitat group furthest away from sea (landward terrestrial habitat), and the coastal marsh wetland habitat group had the lowest value. This finding indicated that as the community developed, the diversity in the first and the last habitat groups would increase, while that in the coastal marsh wetland habitat group would gradually decline. Due to anthropogenic and natural disturbances, H. littoralis in Baguang has already exhibited some endangered signs and more protection is urgently needed.

Key words: Enhalus acoroide, clonal diversity, geneticdiversity, microsatellite, genetic differentiation.