Abstract: Studies on the releasing pattern of phenolics during the decomposition of Chinese fir stump root and on its allelopathy show that the phenolics contents in stump-roots decreased with their decomposition.Roots had a higher content of phenolics than heart stumps,and edge stumps had the least.The phenolics was released during decomposition,and accumulated in the soils around stump-roots.Pot culture experiment showed that phenolics affected the germination of Chinese fir seeds.The correlation analysis between the density of Chinese fir stump-root and the tree height and base diameter (BD) of its saplings proved that Chinese fir stump-roots had a negative impact on the growth of the next generation of Chinese fir plantations.It is suggested that the traditional operation of Chinese fir plantations should be reformed,and the stump-roots should be cleared from woodland before reforestation.

Key words: Stump-root, Phenolics, Chinese fir, Allelopathy, Decomposition, plant community, environmental factor., Miao Archipelago, functional diversity, species diversity, structural diversity