Abstract: Two sample plots(plot Ⅰ, pure Dicranopteris dichotoma community and plot Ⅱ, D. dichotoma community under Chinese fir forest)are comparatively investigated, Because of their environmental differences, the two communities have different dynamic patterns of growth and biomass: the maximum growth speed and aboveground-underground biomass in plot Ⅰ are at September, whereas those in plot Ⅱ are at October, As multiple regression anatysis indicates, the aboveground biomass of Dicranopteris dichotoma communities is correlated with the amount of pinnules, length of petioles and environmental illumination, while the underground biomass is correlated with the abovoground biomass, amount of pinnules, length of petioles, environmental illumination and soil moisture content.

Key words: Populus cathayana, dioecious, aluminum stress, ecophysiological , characteristics