Structure and Distribution Patterns of Ceriops tagal Populations at Different Tidal Zones of Dongzhaigang Harbor,Hainan

Key words: 
• population structure /
• distribution pattern /
• Ceriops tagal /
• tidal zone /
• Dongzhaigang Harbor

Abstract: Tidal flooding is one of the most important factors that affect the regional distribution of mangrove plants. The basal stem diameter,height,crown,density and spatial distribution patterns of Ceriops tagal populations in different tidal zones of Dongzhaigang Harbour in Hainan Island were observed and determined for comparative analysis. C. tagal populations among different tidal zones were found different obviously in the population structure,distribution and distribution pattern as the extent of tidal flooding varied. The seedling populations of C. tagal had the highest proportion in all the tidal zones and grew as stable or steady-growing populations,but their densities were highly different: 986 plants/hm² in the external tidal zone,43873 plants/hm² in the middle tidal zone,and 141360 plants/hm² in the inner tidal zone. The basal stem diameter and the crown structure of the C. tagal populations were not obviously different,but the height was obviously different: C. tagal populations tended to grow higher from the inner to the external tide zones. C. tagal populations tended to be distributed randomly and were aggregately distributed in the middle and inner tidal zones. For the dynamics of spatial distribution patterns of the C. tagal populations the seedlings were aggregately distributed while the young and mature trees were scattered randomly in the external tidal zone,but the seedlings and young trees were aggregately distributed and the mature trees randomly distributed in both the middle and inner tidal zones.