Study On Population Ecology Of The Mangrove Sonneratia Caseolaris At FuTian, ShenZhen

Sonneratia caseolaris is one of the pioneer species of mangroves. The research results on the population ecology of S. caseolaris are not only helpful to know its biological and ecological characteristics, but also to its restoration, afforestation and protection.Population structure, interspecific relationship,ecological fields, etc. were analyzed. The results are as follows:(1)The heights of individuals of S. caseolaris population ranged mostly from 6~14m. The TH values of 50%~60% of the individuals were lower than their average values. The DBH s of the individuals ranged mostly from 5~20 m or from 15~30 m. The TC values of 46%~62% of the individuals were lower than their average values. The crown structure of the population was influenced largely by density, competition of individuals for space etc., and crown diameter was largely negatively correlated with population density. S. caseolaris population was a growing one, and its survival curves had a convex shape. The population formed by natural regeneration had a clumped distribution pattern. Natural regeneration and dispersal of artificial S. caseolaris population had more or less occurred, which may increase the structural complexity and stability of the artificial population.(2)In a natural S. caseolaris + S. apetala forest, the horizontal spatial pattern of populations of S. caseolaris, S. apetala, Kandelia candel and Aegiceras corniculatum showed clumped distribution. Negative spatial correlations were found between S . caseolaris and S. apetala , S . caseolaris and K. candel , S. caseolaris and A. corniculat um , A. corniculat um and S. apetala , K. candel and A. corniculat um ,and positive spatial correlations between K. can2del and S. caseolaris. However, all these correlations were not statistically significant . In the forest, the mixed degree of S. caseolaris and K. candel and other species was moderate ,while that of S. apetala and A . cornicu2lat um and other species relatively low. Individuals of S . caseolaris and S . apetala showed a clear difference in perimeters at breast height ,while other species a moderate difference. Individuals of S. caseolaris showed a clear difference in heights , while other species a moderate difference. The spatial indices and techniques used could effectively describe the spatial characteristics of species.(3)The ecological factor field around the individuals of S. caseolaris was obvious, and its spatial distribution characteristics was the comprehensive result of the roles of the species...