Abstract:

The effects of the density on the storage of biomass，carbon and nutrient elements were investigated under five kinds of Fargesia denudata communities with different density in the primitive F. denudataPicea purpurea forest in May and October，2005. At the end of growing season，the total biomass，net production，average stem biomass，carbon and nutrient storage of plant and soil all increased from (80±5) trees·m^-2 to (260±9) trees·m^-2 but decreased at (310±15) trees·m^-2，showing that the suitable stem density range was from 210 to 260 trees·m^-2 for the bamboo to grow. The order of nutrient storages was K>N>Ca>P>Mg for all bamboo communities. As a whole，for the lower density communities，carbon and nutrient were allocated more to below ground for occupying belowground spatial and nutrient resource，but more to aboveground for those with higher density to occupy aboveground spatial resource，implying that the ecological adaptive strategy of F. denudata was primarily determined by the density. Furthermore，in the system of plant and soil，the carbon storage ratio of plant to soil increased with density increasing but decreased at the highest density. Though the nutrient storages of N，P，K and Mg were abundant in soil，and the storage of available N and K had no more difference，among all densities，the storage of available P decreased with density increasing，implying that the lack of available P regulated the growth of F. denudata community.

Key words: Fargesia denudata, density, biomass, carbon, nutrient, stock