Studies on the Interspecific Association among the Kingdonia uniflora and Its Companion Species in Taibai Mt.

Kingdonia uniflora is one kind of the endemic species in China.Based upon a 2×2 contingency table,a series of techniques including analysis of variance ratio for testing the overall association of all species,X²-test for testing the property of the interspecific association and association indices(Ochiai,Dice,Jaccard)for showing relationship degree of the interspecific association,were used to determine and measure the interspecific association among the 136 species-pair of Kingdonia uniflora and its 16 compa-nion species.The results indicated that the overall association of all species is significantly positive.All species-pair were checked by X²-test,in which 17 species-pair were observed to have very significant positive association at 0.01,6 species-pair at 0.05 and 6 species-pair revealed very significant negative association at 0.01,3 species-pair at 0.05.All species-pair were also checked by Ochiai index,majorities of species-pair were lower,and just 7 positive association species-pair overtop 0.5.These reflect the independence of species-pair.The loose interspecific association is possibly related to the development stage of communities and ecological features of species.