Abstract:

The biomass of undergrowth plant in Chinese fir plantation stands at different site indices and forest age was studied.The results showed that total biomass of undergrowth plant and biomass of shrub layer were basically increasing with forest age except poor growth of undergrowth plant in middle-aged forest, but the variation of herb layer biomass was more complicated. The accumulation quantity of litter of Chinese fir forest and its undergrowth plant at different site indices and forest ages also existed obvious difference. The accumulation quantity of Chinese fir litter was increasing with forest age, the litter quantity of undergrowth plant at 14 site indices was increasing with forest age, but at 16 and 18 site indices, the litter quantity of undergrowth plant was also increasing with forest age except in middle-aged plantation.Through the analysis of quantitative modelⅠ,the results showed that forest stand density, forest age,topography and soil conditions were important factors affecting biomass of undersgrowth plant, Chinese fir litter and undergrowth plant litter,especially forest stand density and forest age.

Key words: Chinese fir, Undergrowth plant, Litter, Biomass, Forecasting models