Species Diversity and Quantity of Shrub Layers in the Forest Main Communities of Jiulian Mountain,Jiangxi Province in South China

Field investigation was carried out for species diversity of shrub layers of the main communities in Jiulian Mountain of Jiangxi Province in south China.The main indices included the Shannon-Wiener index(SW),the simpson dominance index(SN),the homogenization index(PW) and the sum of dominance ratio(SDR) were adopted in the paper to study the species diversity and the importance of shrub layers.The results indicated that the different indices can effectively express the composition and structure characteristics of the shrub layers:(1)The value of Shannon-Wiener index was the highest in the shrub layer of form.Castanopsis fargesii(2.353) and which was the lowest in the shrub layer form.Rhododendron simiarum(0.973).(2)The results indicated that the value of homogenization indices of different kinds of population were alike,the homogenization index was the highest in Form.Phyllostachys pubeseens(0.961)and was the lowest in form.Cunninghamia lanceolata(0.564).(3)The value of simpson dominance index was the highest in the shrub layer of form.Cunninghamia lanceolata(0.431) and was the lowest in that of form.Castanopsis fargesii(0.091),the results indicated that the values of dominance indices and the values of Shannon-Wiener indices in the same shrub layer were negative correlation.According to the values of Shannon-Wiener diversity indices of different layers of all investigated communities,the results indicated that the average Shannon-Wiener diversity index was the highest in the shrub layer and was the lowest in the upper canopy layer,and the density of the population in the shrub layer was higher than in the canopy layer.There was a great difference in the species between shrub layer and canopy layer.These results indicated the trend of movement and succession of different populations in different forest communities of Jiulian Mountain.