Abstract: In this paper, a quantitative analysis was conducted on the functional modules’ biomass structure and the relationships between biomass allocation and age of Acanthopanax senticosus population in three different habitats of coniferous and broad-leaved mixed forest, Quercus mongolica forest, and secondary miscellaneous forest. The results showed that the individual growth and modules’ biomass accumulation of A. senticosus population were closely related to habitat conditions. The mean values of all functional modules’ biomass under different ecological environments exhibited the same regularity, i.e., stem modules>rhizome modules >leaf modules, and there were some similarities in the whole population of A. senticosus. The individual and each module’s biomass of the population differed with the canopy density of forests, being larger in Q. mongolica forest with 40% of canopy density than in coniferous and broad-leaved mixed forest and secondary miscellaneous forest. The variations of ramet biomass allocation under different habit conditions indicated the important strategies in growth regulation and biomass allocation, i.e., more biomass was allocated to the leaves preferentially on small ramets, especially in the secondary miscellaneous forest with biggest canopy density, to ensure the full material product. There was the same regulation of heterogeneous speed growth in the relative weight increase of the leaves, stems and ramets of the population under the three habitat conditions.

Key words: Musa paradisiaca, Higher CO₂ concentration, Photosynthetic rate, Leaf nitrogen partition