Abstract: This paper analyzed the population structure of Alsophila spinulosa in seven plos by the method of spatial sere substituting for time sere,and measured its spatial distribution pattern and dynamics by applying five aggregate indices,C,K,m*,m*/m and Iδ.The spatial distribution pattern with different quadrat scale was examined,according to the map of individual location.The results indicated that the population structure of Alsophila spinulosa in the seven plots presented growing,stable,adult or senescent type,and the spatial distribution pattern was changed from clump to random with the development of Alsophila spinulosa population.The values of dispersion index Iδ of the population decreased with increasing quadrat scale.

Key words: Wet deposition, Red tide, Changjiang River estuary, Nutrient element