The relationship between shrub species diversity and stand spatial structure was examined in Chinese fir public welfare forests with different stand ages (young forests, middle aged forests and near matured forests) in Fushou Forest Farm of Pingjiang County, Hunan Province of China, based on the measurements of 18 permanent plots. Five indices (mingling index, competition index, stand layer index, uniform angle scale and open degree of stand) were used to describe the spatial structure of Chinese fir stands, and four indices (Simpson diversity,...