BIOMASS AND NET PRODUCTION IN A BAMBOO PHYLLOSTACHYS-BAMBUSOIDES STAND

Biomass and net production were measured in a Phyllostachys bambusoide s stand in Kyoto Prefecture, central Japan, which had carried out greg arious flowering in 1969 and has been recovering vegetatively. The cul m density fluctuated around an average value of 12 040 ha-1 during the research period (1985-91). Annual recruitment and mortality rates of culms were 1340 and 1133 ha-1, respectively. The mean diameter at brea st height increased from 7.28 cm in 1985 to 8.68 cm in 1991, and the b iomass of culms increased from 71.3 to 111.6 t h-1 over the same time period. Branch and leaf biomasses were almost constant, 10.0 and 9.4 t ha-1 on average, respectively. The leaf area index of the stand was 1 1.6 ha ha-1, which is one of the largest values found in Japanese fore sts. The belowground biomass of 32.6 t ha-1 for rhizomes and 14.8 t ha -1 for fine roots resulted in the smaller ratio of aboveground parts t o the root system (2.38) than those determined for forest stands. The amount of litterfall, excluding culms and large branches, was large (9 .13 t ha-1 year-1), corresponding to those measured in equatorial stan ds. The aboveground net production was 24.6 t ha-1 year-1, larger than the average value reported for forest stands under similar weather co nditions.