Species diversity of various tropical forest types along the altitude gradient at Bawangling National Nature Reserve on the Hainna island of south China, were compared with four diversity indexes, Shannon Wiener's index, Simpson's index, Chao's estimator and the second order jack knife estimator. Base on these indexes, a diversity spectrum along the vertical belt were drew with the assist of spatial analysis technique of geographic information system. The results indicate that the species diversity in t...