Abstract: In recent decade,the additive partitioning of species diversity has been revived,and used to describe a variety of diversity patterns.This paper analyzed the additive partitioning of tree species diversity in Tiantong National Forest Park,based on species richness,Shannon index and Simpson index.For species richness,small part was partitioned within plots,and most diversity was partitioned among plots or (sub-) associations.For example,in Schimeto-Castanopsietum fargesii association,only 20.3% of the species richness was assigned within plots.However,for Shannon index and Simpson index,most diversity was partitioned within plots,because these indices gave consideration to both species number and its abundance in each plot.The results of additive partitioning were also compared to those of traditional method in this paper.

Key words: Growth and decline on Nitraria community, Precipitation, Underground water level